research article gravity modulation effects of
TRANSCRIPT
Research ArticleGravity Modulation Effects of Hydromagnetic Elastico-ViscousFluid Flow past a Porous Plate in Slip Flow Regime
Debasish Dey
Department of Mathematics Dibrugarh University Dibrugarh Assam 786 004 India
Correspondence should be addressed to Debasish Dey debasish41092gmailcom
Received 17 February 2014 Accepted 11 March 2014 Published 21 May 2014
Academic Editors I Hashim and Y Liu
Copyright copy 2014 Debasish DeyThis is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
The two-dimensional hydromagnetic free convective flow of elastico-viscous fluid (Walters liquid Model B1015840) with simultaneousheat and mass transfer past an infinite vertical porous plate under the influence of gravity modulation effects has been analysedGeneralized Navierrsquos boundary condition has been used to study the characteristics of slip flow regime Fluctuating characteristicsof temperature and concentration are considered in the neighbourhood of the surface having periodic suction The governingequations of fluidmotion are solved analytically by using perturbation technique Various fluid flow characteristics (velocity profileviscous drag etc) are analyzed graphically for various values of flowparameters involved in the solution A special emphasis is givenon the gravity modulation effects on both Newtonian and non-Newtonian fluids
1 Introduction
The analysis of viscoelastic fluid flow is one of the importantfields of fluid dynamics The complex stress-strain rela-tionships of viscoelastic fluid flow mechanisms are usedin geophysics chemical engineering (absorption filtration)petroleum engineering hydrology soil-physics biophysicsand paper and pulp technologyThe viscosity of the viscoelas-tic fluid signifies the physics of the energy dissipated duringthe flow and its elasticity represents the energy stored duringthe flow AsWalters liquid (Model B1015840) contains both viscosityand elasticity it is different from Newtonian fluid because theNewtonian fluid does not have the concept of elasticity as itdiscusses only the concept of energy dissipation
The phenomenon of transient free convection flow froma vertical plate has been analysed by Siegel [1] Gebhart[2] has studied the fluid motion in the presence of naturalconvection from vertical elements Chung and Anderson [3]have investigated the nature of unsteady fluid flow includingthe effects of natural convection Schetz and Eichhorn [4]have investigated the above unsteady problem in the vicinityof a doubly infinite vertical plate Goldstein and Briggs [5]have studied the problem of free convection about verticalplates and circular cylinders Two- and three-dimensional
oscillatory convection in gravitationally modulated fluidlayers have been investigated by Clever et al [6 7] A study ofthermal convection in an enclosure induced simultaneouslyby gravity and vibration has been done by Fu and Shieh [8]Convection phenomenon of material processing in space hasbeen described by Ostrach [9] Li [10] has investigated theeffect of magnetic fields on low frequency oscillating naturalconvection Deka and Soundalgekar [11] have analysed theproblem of free convection flow influenced by gravity mod-ulation by using Laplace transform technique Rajvanshi andSaini [12] have studied the free convection MHD flow pasta moving vertical porous surface with gravity modulationat constant heat flux The influence of combined heat andmass transfer and gravity modulation on unsteady flow pasta porous vertical plate in slip flow regime has been examinedby Jain and Rajvanshi [13]
In this study an analysis is carried out to study theeffects of gravity modulation on free convection unsteadyflow of a viscoelastic fluid past a vertical permeable platewith slip flow regime under the action of transverse magneticfield The velocity field and magnitude of shearing stress atthe plate are obtained and illustrated graphically to observethe viscoelastic effects in combination with other flowparameters
Hindawi Publishing CorporationISRN Applied MathematicsVolume 2014 Article ID 492906 7 pageshttpdxdoiorg1011552014492906
2 ISRN Applied Mathematics
The constitutive equation for Walters liquid (Model B1015840) is
120590119894119896= minus119901119892
119894119896+ 1205901015840
119894119896 1205901015840119894119896
= 21205780119890119894119896minus 211989601198901015840119894119896 (1)
where 120590119894119896 is the stress tensor 119901 is isotropic pressure 119892119894119896is the
metric tensor of a fixed coordinate system 119909119894 V119894is the velocity
vector and the contravariant form of 1198901015840119894119896 is given by
1198901015840119894119896
=
120597119890119894119896
120597119905
+ V119898119890119894119896119898minus V119896119898119890119894119898minus V119894119898119890119898119896 (2)
It is the convected derivative of the deformation rate tensor119890119894119896 defined by
2119890119894119896= V119894119896+ V119896119894 (3)
Here 1205780is the limiting viscosity at the small rate of shear
which is given by
1205780= int
infin
0
119873(120591) 119889120591 1198960= int
infin
0
120591119873 (120591) 119889120591 (4)
119873(120591) being the relaxation spectrumThis idealizedmodel is avalid approximation of Walters liquid (Model B1015840) taking veryshort memories into account so that terms involving
int
infin
0
119905119899119873(120591) 119889120591 119899 ge 2 (5)
have been neglectedWalter [14] reported that the mixture of polymethyl
methacrylate and pyridine at 25∘C containing 305 gm ofpolymer per litre and having density 098 gmmL fits verynearly to this model
2 Mathematical Formulation
An unsteady two-dimensional free convective flow of anelectrically conducting elastico-viscous fluid past a verticalporous plate has been analysed in the presence of gravitymodulation and slip flow regime119860magnetic field of uniformstrength 119861
0is applied in the direction normal to the plate
Induced magnetic field is neglected by assuming very smallvalues ofmagnetic Reynolds number (Crammer andPai [15])The electrical conductivity of the fluid is also assumed to beof smaller order of magnitude Let 1199091015840-axis be taken along thevertical plate and 119910
1015840-axis is taken normal to the plate Let119879119908and 119862
119908be respectively the temperature and the molar
species concentration of the fluid at the plate and let 119879infin
and 119862infin
be respectively the equilibrium temperature andequilibrium molar species concentration of the fluid Thegeometry of the problem is shown by Figure 1
g
y998400
u998400
998400
x998400
Tw and Cw
998400 = minusV0(1 + 120598Aei120596998400 t998400 )
Figure 1 Geometry of the problem
The governing equations of the fluid motion are asfollows
120597V1015840
1205971199101015840= 0 997904rArr V1015840 = minus119881
0(1 + 120598119860119890
11989412059610158401199051015840
)
1205971199061015840
1205971199051015840+ V1015840
1205971199061015840
1205971199101015840= 119892120573 (119879
1015840minus 119879infin) + 119892120573 (119862
1015840minus 119862infin) + ]
12059721199061015840
12059711991010158402
minus
1198960
120588
(
12059731199061015840
12059711991010158402
1205971199051015840
+ V101584012059731199061015840
12059711991010158403) minus
1205901198612
01199061015840
120588
1205971198791015840
1205971199051015840+ V1015840
1205971198791015840
1205971199101015840=
119870
120588119862119901
12059721198791015840
12059711991010158402
1205971198621015840
1205971199051015840+ V1015840
1205971198621015840
1205971199101015840= 119863
12059721198621015840
12059711991010158402
(6)
In fact nearly two hundred years ago Navier [16] pro-posed amore general boundary conditionwhich includes thepossibility of fluid slipNavierrsquos proposed boundary conditionassumes that the velocity at a solid surface is proportional tothe shear rate at the surface
The boundary conditions of the problem are
1199061015840= ℎ10158401205901015840
119909119910 119879
1015840= 119879119908+ 120598 (119879
119908minus 119879infin) 11989011989412059610158401199051015840
1198621015840= 119862119908+ 120598 (119862
119908minus 119862infin) 11989011989412059610158401199051015840
at 1199101015840 = 0
1199061015840997888rarr 0 119879
1015840997888rarr 119879infin 119862
1015840997888rarr 119862
infin
as 1199101015840 997888rarr infin
(7)
where 1205901015840119909119910
= 1205780(12059711990610158401205971199101015840) minus 1198960((1205972119906101584012059711991010158401205971199051015840) + V1015840(1205973119906101584012059711991010158403))
3 Method of Solution
The gravitational acceleration is considered as
119892 = 1198920minus 119894119892111989011989412059610158401199051015840
1198921= 120598119886119892
0 (8)
ISRN Applied Mathematics 3
Let us introduce the following nondimensional quantities
119910 =
11991010158401198810
] 119905 =
11990510158401198810
2
4] 120596 =
4]1205961015840
1198810
2
119906 =
1199061015840
1198810
120579 =
1198791015840minus 119879infin
119879119908minus 119879infin
119862 =
1198621015840minus 119862infin
119862119908minus 119862infin
Gr =1198920120573] (119879119908minus 119879infin)
1198810
3 Gr =
11989201205730] (119862119908minus 119862infin)
1198810
3
119872 =
1205901198612
0]
1205881198810
2 119896 =
11989601198810
2
120588]2
Pr =1205780119862119875
119870
Sc = ]119863
ℎ = ℎ10158401205881198812
0
(9)
where 119910 is the displacement variable 119905 is the time 120596 isthe frequency of oscillation 119906 is the dimension velocity 120579is the dimensionless temperature 119862 is the dimensionlessconcentration Gr is Grashof number for heat transfer Gm isGrashof number for mass transfer119872 is magnetic parameter119896 is viscoelastic parameter Pr is the Prandtl number Sc is theSchmidt number 119886 is gravity modulation parameter and ℎ isthe slip parameter
Then the nondimensional forms of the governing equa-tions of motions are as follows
1
4
120597119906
120597119905
minus (1 + 120598119860119890119894120596119905)
120597119906
120597119910
= (Gr120579 + Gm119862) (1 minus 119894120598120572119890119894120596119905) +
1205972119906
1205971199102minus119872119906
minus 119896[
1
4
1205973119906
1205971199102120597119905
minus (1 + 120598119860119890119894120596119905)
1205973119906
1205971199103]
1
4
120597120579
120597119905
minus (1 + 120598119860119890119894120596119905)
120597120579
120597119910
=
1
Pr1205972120579
1205971199102
1
4
120597119862
120597119905
minus (1 + 120598119860119890119894120596119905)
120597119862
120597119910
=
1
Pr1205972119862
1205971199102
(10)
Boundary conditions in the dimensionless form are given asfollows
119906 = ℎ [
120597119906
120597119910
minus 119896
1
4
1205972119906
120597119910120597119905
minus (1 + 120598119860119890119894120596119905)
1205972119906
1205971199102]
120579 = 1 + 120598119890119894120596119905 119862 = 1 + 120598119890
119894120596119905
at 119910 = 0
119906 997888rarr 0 120579 997888rarr 0 119862 997888rarr 0
as 119910 997888rarr infin
(11)
Assuming small amplitude of oscillations (120598 ≪ 1) in theneighbourhood of the plate the velocity temperature andconcentration are considered as
119906 = 1199060+ 1205981198901198941205961199051199061+ 119900 (120598
2)
120579 = 1205790+ 1205981198901198941205961199051205791+ 119900 (120598
2)
119862 = 1198620+ 1205981198901198941205961199051198621+ 119900 (120598
2)
(12)
Using (12) in (10) and equating the like powers of 120598 andneglecting the higher powers of 120598 we get
119896119906101584010158401015840
0+ 11990610158401015840
0+ 1199061015840
0minus119872119906
0= minus (Gr120579
0+ Gm119862
0)
119896119906101584010158401015840
1+ 11990610158401015840
1(1 minus 119896
119894120596
4
) + 1199061015840
1minus (119872 +
119894120596
4
) 1199061
= Gr (1205721205790minus 1205791) + Gm (120572119862
0minus 1198621)
minus 1198601199061015840
0minus 119896119860119906
101584010158401015840
0
(13)
1
Pr12057910158401015840
0+ 1205791015840
0= 0
1
Pr12057910158401015840
1+ 1205791015840
1minus
119894120596
4
1205791= minus1205791015840
0
1
Sc11986210158401015840
0+ 1198621015840
0= 0
1
Sc11986210158401015840
1+ 1198621015840
1minus
119894120596
4
1198621= minus1198621015840
0
(14)
Relevant boundary conditions for solving the above equa-tions are as follows
1199060= ℎ [119906
1015840
0+ 11989611990610158401015840
0]
1199061= ℎ [119906
1015840
1minus 119896
119894120596
4
1199061015840
1minus 11986011990610158401015840
0minus 11990610158401015840
1]
1205790= 1205791= 1198620= 1198621= 1
at 119910 = 0
1199060= 1199061= 1205790= 1205791= 1198620= 1198621= 0
as 119910 997888rarr infin
(15)
Equations (14) are solved by using the boundary conditions(15) and their solutions are given by
1205790= 119890minusPr119910
1205791= 11986231198901205721119910+ 1198624119890minus1205722119910+
1198944Pr120596
119890minusPr119910
1198620= 119890minusSc119910
1198621= 11986251198901205723119910+ 1198626119890minus1205724119910+
1198944Sc120596
119890minusSc119910
(16)
The presence of elasticity in the governing fluid motionconstitutes a third-order differential equation (13) but for
4 ISRN Applied Mathematics
Newtonian fluid 119896 = 0 then the differential equation redu-ces to of order two And also it is seen that as there areinsufficient boundary conditions for solving (13) we usemultiparameter perturbation technique Since 119896 which is ameasure (dimensionless) of relaxation time is very small fora viscoelastic fluid with small memory thus following RayMahapatra and Gupta [17] and Reza and Gupta [18] we usethe multiparameter perturbation technique and we consider
1199060= 11990600+ 11989611990601+ 119900 (119896
2)
1199061= 11990610+ 11989611990611+ 119900 (119896
2)
(17)
Using the perturbation scheme (17) in (13) and equating thelike powers of 119896 and neglecting the higher orders power of 119896we get
11990610158401015840
00+ 1199061015840
00minus119872119906
00= minus (Gr120579
0+ Gm119862
0)
11990610158401015840
00+ 1199061015840
00minus119872119906
00= minus119906101584010158401015840
00
11990610158401015840
10+ 1199061015840
10minus (119872 +
119894120596
4
) 11990610
= 120572 (Gr1205790+ Gm119862
0) minus 119860119906
1015840
0minus (Gr120579
1+ Gm119862
1)
11990610158401015840
11+ 1199061015840
11minus (119872 +
119894120596
4
) 11990611
= minus1198601199061015840
01minus 119860119906101584010158401015840
00minus 119906101584010158401015840
10minus
119894120596
4
11990610158401015840
10
(18)
The modified boundary conditions for solving the aboveequations are
11990600= ℎ1199061015840
00 119906
01= ℎ [119906
1015840
01+ 11990610158401015840
00] 119906
10= ℎ1199061015840
10
11990611= ℎ [119906
1015840
11minus
119894120596
4
1199061015840
10+ 11986011990610158401015840
00+ 11990610158401015840
10]
at 119910 = 0
11990600997888rarr 0 119906
01997888rarr 0 119906
10997888rarr 0 119906
11997888rarr 0
as 119910 997888rarr infin
(19)
The solutions of (18) relevant to the above boundary condi-tions are presented as follows
11990600= 1198628119890minus1205726119910+ 1198601119890minus1198601119910+ 1198602119890minus1198602119910
11990601= 11986210119890minus1205726119910+ 1198603119910119890minus1205726119910+ 1198604119890minus1198601119910+ 1198605119890minus1198602119910
11990610= 11986212119890minus1205728119910+ (1198606+ 1198941198607) 119890minusPr119910
+ (1198608+ 1198941198609) 119890minusSc119910
+ 11989411986010119890minus1205726119910
+ (11986011+ 11989411986012) 119890minus1198601119910+ (11986013+ 11989411986014) 119890minus1198602119910
+ (11986015+ 11989411986016) 119890minus1205722119910+ (11986017+ 11989411986018) 119890minus1205724119910
11990610= 11986214119890minus1205728119910+ (11986036+ 11989411986037) 119890minus1205726119910+ 11989411986038119910119890minus1205726119910
+ (11986039+ 11989411986040) 119890minus1198601119910+ (11986041+ 11989411986042) 119890minus1198602119910
+ (11986043+ 11989411986044) 119910119890minus1205728119910+ (11986045+ 11989411986046) 119890minusPr119910
+ (11986047+ 11989411986048) 119890minusSc119910
+ (11986049+ 11989411986050) 119890minus1205722119910
+ (11986051+ 11989411986052) 119890minus1205724119910
(20)
The constants of the solutions are not presented here for thesake of brevity
Knowing the velocity field the shearing stress at the plateis defined as
Sh = [
120597119906
120597119910
minus 119896
1
4
1205972119906
120597119910120597119905
minus (1 + 120598119860119890119894120596119905)
1205972119906
1205971199102]
119910=0
(21)
The effects of gravity modulation on free convectiveflow of an elastico-viscous fluid with simultaneous heat andmass transfer past an infinite vertical porous plate under theinfluence of transverse magnetic field have been analyzedFigures 2 to 5 represent the pattern of velocity profile against119910 for various values of flow parameters involved in thesolution The effect of viscoelasticity is exhibited throughthe nondimensional parameter ldquo119896rdquo The nonzero values of119896 characterize viscoelastic fluid where 119896 = 0 character-izes Newtonian fluid flow mechanisms In this study mainemphasis is given on the effect of viscoelasticity on thegoverning fluid motion and also on the difference in flowpattern of both Newtonian and non-Newtonian fluids in thepresence of various physical properties considered in thisproblem
It is seen from Figure 2 that both Newtonian and non-Newtonian fluid flows accelerate asymptotically in the neigh-bourhood of the plate and then they experience a declinetrend as we move away from the plate The nonzero value ofvelocity profile at 119910 = 0 represents the strength of slip at theplate Also it can be concluded that the growth in viscoelas-ticity slows down the speed of fluid flow Effects of gravitymodulation parameter 119886 on the governing fluid motions areshown in Figure 3 and it is observed that as 119886 increases thespeed of fluid flow increases along with the increasing valuesof 119896 = (0 02 and 04) Application of transverse magneticfield leads to the generalization of Lorentz force and its effectis displayed by the nondimensional parameter 119872 Figure 4shows the impact of magnetic parameter on the fluid flowagainst the displacement variable 119910 As magnetic parameterincreases the strength of Lorentz force rises and as a resultthe flow is retarded It is also noticed that as119872 decreases theeffect of viscoelasticity is seen prominent
ISRN Applied Mathematics 5
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
k = 0
k = 04k = 02
Figure 2 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 119886 = 1ℎ = 01 120596 = 5 119860 = 1 120596119905 = 120587
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
a = 1 k = 0a = 1 k = 02a = 1 k = 0
a = 3 k = 04a = 3 k = 02a = 3 k = 0
Figure 3 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 ℎ = 01120596 = 5 119860 = 1 120596119905 = 120587
Grashof number is defined as the ratio of buoyancy forceto viscous force and its positive value identifies the flow pastan externally cooled plate and the negative value characterizesthe flow past an externally heated plate Figure 5 shows thatas Gr increases the resistance of fluid flow diminishes and asa consequence the speed enhances along with the increasingvalues of visco-elastic parameter Again when the flow passesan externally heated plate (Gr = minus10) a back flow is noticedin case of both Newtonian and non-Newtonian fluids
4 Results and Discussions
Knowing the velocity field it is important from a practicalpoint of view to know the effect of viscoelastic parameteron shearing stress or viscous drag Figures 6 to 8 depictthe magnitude of shearing stress at the plate of viscoelasticfluid in comparison with the Newtonian fluid for the variousvalues of flow parameters involved in the solution Thefigures notify that the growth in viscoelasticity subdues themagnitude of viscous drag at the surface Prandtl numberplays a significant role in heat transfer flow problems as it
0 2 4 6 8 10 120
05
1
15
2
25
3
35
u
y
M = 5 M = 3 M = 2 M = 1
Figure 4 Pr = 10 Sc = 7 Gm = 5 Gr = 10 119890 = 001 ℎ = 01 120596 = 5119860 = 1 120596119905 = 120587
minus3 minus2 minus1 0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
Gr = 7 Gr = 10Gr = minus10
Figure 5 Pr = 10 Sc = 7 Gm = 5 119890 = 001 ℎ = 01 120596 = 5 119860 = 1120596119905 = 120587119872 = 2
helps to study the simultaneous effect of momentum andthermal diffusion in fluid flow Effect of Prandtl number onthe magnitude of shearing stress is seen in Figure 6 and it canbe concluded that the magnitude of shearing stress increasesrapidly for Pr lt 8 of both Newtonian and non-Newtonianfluids but for higher values of Pr (gt8) it increases steadily Inmass transfer problems the importance of Schmidt numbercannot be neglected as it studies the combined effect ofmomentum and mass diffusion The same phenomenon asthat in case of growth in Prandtl number is experiencedagainst Schmidt number for various values of viscoelasticparameter (Figure 7) Effect of gravity modulation parameter119886 on the viscous drag is shown in Figure 8 and it is revealedthat as 119886 increases themagnitude of shearing stress increases
The rate of heat transfer and rate of mass transfer are notsignificantly affected by the presence of viscoelasticity of thegoverning fluid flow
5 Conclusions
From the present study we make the following conclusions
(i) Both Newtonian and non-Newtonian fluid flowsaccelerate asymptotically in the neighbourhood of theplate
(ii) Growth in viscoelasticity slows down the speed offluid flow
6 ISRN Applied Mathematics
55 6 65 7 75 8 85 9 9502468
101214161820
k = 0
k = 04k = 02
Magnitude of shearing stress
Pran
dtl n
umbe
r
Figure 6 Sc = 7 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
6 65 7 75 8 85 9 9502468
10121416
k = 0
k = 04k = 02
Magnitude of shearing stress
Schm
idt n
umbe
r
Figure 7 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
(iii) Effect of viscoelasticity is seen prominent during thelower order magnitude of magnetic parameter
(iv) A back flow is experienced in the motion governingfluid flow past an externally heated plate
(v) As gravity modulation parameter 119886 increases themagnitude of shearing stress experienced by Newto-nian as well as non-Newtonian fluid flows increase
Conflict of Interests
The author does not have any conflict of interests regardingthe publication of paper
Acknowledgment
Theauthor acknowledges Professor Rita Choudhury Depart-ment of Mathematics Gauhati University for her encourage-ment throughout this work
75 8 85 9 95 100
1
2
3
4
5
6
k = 0
k = 04k = 02
Magnitude of shearing stress
Gra
vity
mod
ulat
ion
para
met
er
Figure 8 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 Sc = 7 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
References
[1] R Siegel ldquoTransient-free convection from a vertical flat platerdquoTransactions of the American Society of Mechanical Engineersvol 80 pp 347ndash359 1958
[2] B Gebhart ldquoTransient natural convection from vertical ele-mentsrdquo Journal of Heat Transfer vol 83 pp 61ndash70 1961
[3] P M Chung and A D Anderson ldquoUnsteady laminar freeconvectionrdquo Journal of Heat Transfer vol 83 pp 474ndash478 1961
[4] J A Schetz and R Eichhorn ldquoUnsteady natural convection inthe vicinity of a doubly infinite vertical platerdquo Journal of HeatTransfer vol 84 pp 334ndash338 1962
[5] R J Goldstein and D G Briggs ldquoTransient-free convectionabout vertical plates and circular cylindersrdquo Journal of HeatTransfer vol 86 pp 490ndash500 1964
[6] R Clever G Schubert and F H Busse ldquoTwo-dimensionaloscillatory convection in a gravitationally modulated fluidlayerrdquo Journal of Fluid Mechanics vol 253 pp 663ndash680 1993
[7] R Clever G Schubert and F H Busse ldquoThree-dimensionaloscillatory convection in a gravitational modulated fluid layerrdquoPhysics of Fluids A vol 5 no 10 pp 2430ndash2437 1992
[8] W S Fu and W J Shieh ldquoA study of thermal convection inan enclosure induced simultaneously by gravity and vibrationrdquoInternational Journal of Heat and Mass Transfer vol 35 no 7pp 1695ndash1710 1992
[9] S Ostrach ldquoConvection phenomena of importance for materi-als processing in spacerdquo in Proceedings of the COSPAR Sympo-sium on Materials Sciences in Space pp 3ndash33 Philadelphia PaUSA 1976
[10] B Q Li ldquoThe effect of magnetic fields on low frequency oscil-lating natural convectionrdquo International Journal of EngineeringScience vol 34 no 12 pp 1369ndash1383 1996
[11] R K Deka and V M Soundalgekar ldquoGravity modulationeffects on transient-free convection flow past an infinite verticalisothermal platerdquoDefence Science Journal vol 56 no 4 pp 477ndash483 2006
[12] S C Rajvanshi and B S Saini ldquoFree convection MHD flowpast a moving vertical porous surface with gravity modulationat constant heat fluxrdquo International Journal of Theoretical andApplied Sciences vol 2 no 1 pp 29ndash33 2010
[13] S R Jain and S C Rajvanshi ldquoInfluence of gravity modulationviscous heating and concentration on flow past a vertical
ISRN Applied Mathematics 7
plate in slip flow regime with periodic temperature variationsrdquoInternational Journal of Theoretical and Applied Science vol 3no 1 pp 16ndash22 2011
[14] K Walter ldquoNon-Newtonian effects in some elastico-viscousliquids whose behavior at small rates of shear is characterizedby a general linear equation of staterdquo The Quarterly Journal ofMechanics and Applied Mathematics vol 15 pp 63ndash76 1962
[15] K R Crammer and S Pai Magneto-Fluid Dynamics for Engi-neers and Applied Physicist McGraw- Hill New York NY USA1973
[16] C L M H Navier Memoirs de LrsquoAcademie Royale des Sciencesde Lrsquoinstitut de France vol 1 1823
[17] T R Mahapatra and A S Gupta ldquoStagnation-point flow ofa viscoelastic fluid towards a stretching surfacerdquo InternationalJournal of Non-Linear Mechanics vol 39 no 5 pp 811ndash8202004
[18] M Reza and A S Gupta ldquoMomentum and heat transfer in theflow of a viscoelastic fluid past a porous flat plate subject tosuction or blowingrdquoWorld Academy of Science Engineering andTechnology vol 23 pp 960ndash963 2008
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2 ISRN Applied Mathematics
The constitutive equation for Walters liquid (Model B1015840) is
120590119894119896= minus119901119892
119894119896+ 1205901015840
119894119896 1205901015840119894119896
= 21205780119890119894119896minus 211989601198901015840119894119896 (1)
where 120590119894119896 is the stress tensor 119901 is isotropic pressure 119892119894119896is the
metric tensor of a fixed coordinate system 119909119894 V119894is the velocity
vector and the contravariant form of 1198901015840119894119896 is given by
1198901015840119894119896
=
120597119890119894119896
120597119905
+ V119898119890119894119896119898minus V119896119898119890119894119898minus V119894119898119890119898119896 (2)
It is the convected derivative of the deformation rate tensor119890119894119896 defined by
2119890119894119896= V119894119896+ V119896119894 (3)
Here 1205780is the limiting viscosity at the small rate of shear
which is given by
1205780= int
infin
0
119873(120591) 119889120591 1198960= int
infin
0
120591119873 (120591) 119889120591 (4)
119873(120591) being the relaxation spectrumThis idealizedmodel is avalid approximation of Walters liquid (Model B1015840) taking veryshort memories into account so that terms involving
int
infin
0
119905119899119873(120591) 119889120591 119899 ge 2 (5)
have been neglectedWalter [14] reported that the mixture of polymethyl
methacrylate and pyridine at 25∘C containing 305 gm ofpolymer per litre and having density 098 gmmL fits verynearly to this model
2 Mathematical Formulation
An unsteady two-dimensional free convective flow of anelectrically conducting elastico-viscous fluid past a verticalporous plate has been analysed in the presence of gravitymodulation and slip flow regime119860magnetic field of uniformstrength 119861
0is applied in the direction normal to the plate
Induced magnetic field is neglected by assuming very smallvalues ofmagnetic Reynolds number (Crammer andPai [15])The electrical conductivity of the fluid is also assumed to beof smaller order of magnitude Let 1199091015840-axis be taken along thevertical plate and 119910
1015840-axis is taken normal to the plate Let119879119908and 119862
119908be respectively the temperature and the molar
species concentration of the fluid at the plate and let 119879infin
and 119862infin
be respectively the equilibrium temperature andequilibrium molar species concentration of the fluid Thegeometry of the problem is shown by Figure 1
g
y998400
u998400
998400
x998400
Tw and Cw
998400 = minusV0(1 + 120598Aei120596998400 t998400 )
Figure 1 Geometry of the problem
The governing equations of the fluid motion are asfollows
120597V1015840
1205971199101015840= 0 997904rArr V1015840 = minus119881
0(1 + 120598119860119890
11989412059610158401199051015840
)
1205971199061015840
1205971199051015840+ V1015840
1205971199061015840
1205971199101015840= 119892120573 (119879
1015840minus 119879infin) + 119892120573 (119862
1015840minus 119862infin) + ]
12059721199061015840
12059711991010158402
minus
1198960
120588
(
12059731199061015840
12059711991010158402
1205971199051015840
+ V101584012059731199061015840
12059711991010158403) minus
1205901198612
01199061015840
120588
1205971198791015840
1205971199051015840+ V1015840
1205971198791015840
1205971199101015840=
119870
120588119862119901
12059721198791015840
12059711991010158402
1205971198621015840
1205971199051015840+ V1015840
1205971198621015840
1205971199101015840= 119863
12059721198621015840
12059711991010158402
(6)
In fact nearly two hundred years ago Navier [16] pro-posed amore general boundary conditionwhich includes thepossibility of fluid slipNavierrsquos proposed boundary conditionassumes that the velocity at a solid surface is proportional tothe shear rate at the surface
The boundary conditions of the problem are
1199061015840= ℎ10158401205901015840
119909119910 119879
1015840= 119879119908+ 120598 (119879
119908minus 119879infin) 11989011989412059610158401199051015840
1198621015840= 119862119908+ 120598 (119862
119908minus 119862infin) 11989011989412059610158401199051015840
at 1199101015840 = 0
1199061015840997888rarr 0 119879
1015840997888rarr 119879infin 119862
1015840997888rarr 119862
infin
as 1199101015840 997888rarr infin
(7)
where 1205901015840119909119910
= 1205780(12059711990610158401205971199101015840) minus 1198960((1205972119906101584012059711991010158401205971199051015840) + V1015840(1205973119906101584012059711991010158403))
3 Method of Solution
The gravitational acceleration is considered as
119892 = 1198920minus 119894119892111989011989412059610158401199051015840
1198921= 120598119886119892
0 (8)
ISRN Applied Mathematics 3
Let us introduce the following nondimensional quantities
119910 =
11991010158401198810
] 119905 =
11990510158401198810
2
4] 120596 =
4]1205961015840
1198810
2
119906 =
1199061015840
1198810
120579 =
1198791015840minus 119879infin
119879119908minus 119879infin
119862 =
1198621015840minus 119862infin
119862119908minus 119862infin
Gr =1198920120573] (119879119908minus 119879infin)
1198810
3 Gr =
11989201205730] (119862119908minus 119862infin)
1198810
3
119872 =
1205901198612
0]
1205881198810
2 119896 =
11989601198810
2
120588]2
Pr =1205780119862119875
119870
Sc = ]119863
ℎ = ℎ10158401205881198812
0
(9)
where 119910 is the displacement variable 119905 is the time 120596 isthe frequency of oscillation 119906 is the dimension velocity 120579is the dimensionless temperature 119862 is the dimensionlessconcentration Gr is Grashof number for heat transfer Gm isGrashof number for mass transfer119872 is magnetic parameter119896 is viscoelastic parameter Pr is the Prandtl number Sc is theSchmidt number 119886 is gravity modulation parameter and ℎ isthe slip parameter
Then the nondimensional forms of the governing equa-tions of motions are as follows
1
4
120597119906
120597119905
minus (1 + 120598119860119890119894120596119905)
120597119906
120597119910
= (Gr120579 + Gm119862) (1 minus 119894120598120572119890119894120596119905) +
1205972119906
1205971199102minus119872119906
minus 119896[
1
4
1205973119906
1205971199102120597119905
minus (1 + 120598119860119890119894120596119905)
1205973119906
1205971199103]
1
4
120597120579
120597119905
minus (1 + 120598119860119890119894120596119905)
120597120579
120597119910
=
1
Pr1205972120579
1205971199102
1
4
120597119862
120597119905
minus (1 + 120598119860119890119894120596119905)
120597119862
120597119910
=
1
Pr1205972119862
1205971199102
(10)
Boundary conditions in the dimensionless form are given asfollows
119906 = ℎ [
120597119906
120597119910
minus 119896
1
4
1205972119906
120597119910120597119905
minus (1 + 120598119860119890119894120596119905)
1205972119906
1205971199102]
120579 = 1 + 120598119890119894120596119905 119862 = 1 + 120598119890
119894120596119905
at 119910 = 0
119906 997888rarr 0 120579 997888rarr 0 119862 997888rarr 0
as 119910 997888rarr infin
(11)
Assuming small amplitude of oscillations (120598 ≪ 1) in theneighbourhood of the plate the velocity temperature andconcentration are considered as
119906 = 1199060+ 1205981198901198941205961199051199061+ 119900 (120598
2)
120579 = 1205790+ 1205981198901198941205961199051205791+ 119900 (120598
2)
119862 = 1198620+ 1205981198901198941205961199051198621+ 119900 (120598
2)
(12)
Using (12) in (10) and equating the like powers of 120598 andneglecting the higher powers of 120598 we get
119896119906101584010158401015840
0+ 11990610158401015840
0+ 1199061015840
0minus119872119906
0= minus (Gr120579
0+ Gm119862
0)
119896119906101584010158401015840
1+ 11990610158401015840
1(1 minus 119896
119894120596
4
) + 1199061015840
1minus (119872 +
119894120596
4
) 1199061
= Gr (1205721205790minus 1205791) + Gm (120572119862
0minus 1198621)
minus 1198601199061015840
0minus 119896119860119906
101584010158401015840
0
(13)
1
Pr12057910158401015840
0+ 1205791015840
0= 0
1
Pr12057910158401015840
1+ 1205791015840
1minus
119894120596
4
1205791= minus1205791015840
0
1
Sc11986210158401015840
0+ 1198621015840
0= 0
1
Sc11986210158401015840
1+ 1198621015840
1minus
119894120596
4
1198621= minus1198621015840
0
(14)
Relevant boundary conditions for solving the above equa-tions are as follows
1199060= ℎ [119906
1015840
0+ 11989611990610158401015840
0]
1199061= ℎ [119906
1015840
1minus 119896
119894120596
4
1199061015840
1minus 11986011990610158401015840
0minus 11990610158401015840
1]
1205790= 1205791= 1198620= 1198621= 1
at 119910 = 0
1199060= 1199061= 1205790= 1205791= 1198620= 1198621= 0
as 119910 997888rarr infin
(15)
Equations (14) are solved by using the boundary conditions(15) and their solutions are given by
1205790= 119890minusPr119910
1205791= 11986231198901205721119910+ 1198624119890minus1205722119910+
1198944Pr120596
119890minusPr119910
1198620= 119890minusSc119910
1198621= 11986251198901205723119910+ 1198626119890minus1205724119910+
1198944Sc120596
119890minusSc119910
(16)
The presence of elasticity in the governing fluid motionconstitutes a third-order differential equation (13) but for
4 ISRN Applied Mathematics
Newtonian fluid 119896 = 0 then the differential equation redu-ces to of order two And also it is seen that as there areinsufficient boundary conditions for solving (13) we usemultiparameter perturbation technique Since 119896 which is ameasure (dimensionless) of relaxation time is very small fora viscoelastic fluid with small memory thus following RayMahapatra and Gupta [17] and Reza and Gupta [18] we usethe multiparameter perturbation technique and we consider
1199060= 11990600+ 11989611990601+ 119900 (119896
2)
1199061= 11990610+ 11989611990611+ 119900 (119896
2)
(17)
Using the perturbation scheme (17) in (13) and equating thelike powers of 119896 and neglecting the higher orders power of 119896we get
11990610158401015840
00+ 1199061015840
00minus119872119906
00= minus (Gr120579
0+ Gm119862
0)
11990610158401015840
00+ 1199061015840
00minus119872119906
00= minus119906101584010158401015840
00
11990610158401015840
10+ 1199061015840
10minus (119872 +
119894120596
4
) 11990610
= 120572 (Gr1205790+ Gm119862
0) minus 119860119906
1015840
0minus (Gr120579
1+ Gm119862
1)
11990610158401015840
11+ 1199061015840
11minus (119872 +
119894120596
4
) 11990611
= minus1198601199061015840
01minus 119860119906101584010158401015840
00minus 119906101584010158401015840
10minus
119894120596
4
11990610158401015840
10
(18)
The modified boundary conditions for solving the aboveequations are
11990600= ℎ1199061015840
00 119906
01= ℎ [119906
1015840
01+ 11990610158401015840
00] 119906
10= ℎ1199061015840
10
11990611= ℎ [119906
1015840
11minus
119894120596
4
1199061015840
10+ 11986011990610158401015840
00+ 11990610158401015840
10]
at 119910 = 0
11990600997888rarr 0 119906
01997888rarr 0 119906
10997888rarr 0 119906
11997888rarr 0
as 119910 997888rarr infin
(19)
The solutions of (18) relevant to the above boundary condi-tions are presented as follows
11990600= 1198628119890minus1205726119910+ 1198601119890minus1198601119910+ 1198602119890minus1198602119910
11990601= 11986210119890minus1205726119910+ 1198603119910119890minus1205726119910+ 1198604119890minus1198601119910+ 1198605119890minus1198602119910
11990610= 11986212119890minus1205728119910+ (1198606+ 1198941198607) 119890minusPr119910
+ (1198608+ 1198941198609) 119890minusSc119910
+ 11989411986010119890minus1205726119910
+ (11986011+ 11989411986012) 119890minus1198601119910+ (11986013+ 11989411986014) 119890minus1198602119910
+ (11986015+ 11989411986016) 119890minus1205722119910+ (11986017+ 11989411986018) 119890minus1205724119910
11990610= 11986214119890minus1205728119910+ (11986036+ 11989411986037) 119890minus1205726119910+ 11989411986038119910119890minus1205726119910
+ (11986039+ 11989411986040) 119890minus1198601119910+ (11986041+ 11989411986042) 119890minus1198602119910
+ (11986043+ 11989411986044) 119910119890minus1205728119910+ (11986045+ 11989411986046) 119890minusPr119910
+ (11986047+ 11989411986048) 119890minusSc119910
+ (11986049+ 11989411986050) 119890minus1205722119910
+ (11986051+ 11989411986052) 119890minus1205724119910
(20)
The constants of the solutions are not presented here for thesake of brevity
Knowing the velocity field the shearing stress at the plateis defined as
Sh = [
120597119906
120597119910
minus 119896
1
4
1205972119906
120597119910120597119905
minus (1 + 120598119860119890119894120596119905)
1205972119906
1205971199102]
119910=0
(21)
The effects of gravity modulation on free convectiveflow of an elastico-viscous fluid with simultaneous heat andmass transfer past an infinite vertical porous plate under theinfluence of transverse magnetic field have been analyzedFigures 2 to 5 represent the pattern of velocity profile against119910 for various values of flow parameters involved in thesolution The effect of viscoelasticity is exhibited throughthe nondimensional parameter ldquo119896rdquo The nonzero values of119896 characterize viscoelastic fluid where 119896 = 0 character-izes Newtonian fluid flow mechanisms In this study mainemphasis is given on the effect of viscoelasticity on thegoverning fluid motion and also on the difference in flowpattern of both Newtonian and non-Newtonian fluids in thepresence of various physical properties considered in thisproblem
It is seen from Figure 2 that both Newtonian and non-Newtonian fluid flows accelerate asymptotically in the neigh-bourhood of the plate and then they experience a declinetrend as we move away from the plate The nonzero value ofvelocity profile at 119910 = 0 represents the strength of slip at theplate Also it can be concluded that the growth in viscoelas-ticity slows down the speed of fluid flow Effects of gravitymodulation parameter 119886 on the governing fluid motions areshown in Figure 3 and it is observed that as 119886 increases thespeed of fluid flow increases along with the increasing valuesof 119896 = (0 02 and 04) Application of transverse magneticfield leads to the generalization of Lorentz force and its effectis displayed by the nondimensional parameter 119872 Figure 4shows the impact of magnetic parameter on the fluid flowagainst the displacement variable 119910 As magnetic parameterincreases the strength of Lorentz force rises and as a resultthe flow is retarded It is also noticed that as119872 decreases theeffect of viscoelasticity is seen prominent
ISRN Applied Mathematics 5
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
k = 0
k = 04k = 02
Figure 2 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 119886 = 1ℎ = 01 120596 = 5 119860 = 1 120596119905 = 120587
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
a = 1 k = 0a = 1 k = 02a = 1 k = 0
a = 3 k = 04a = 3 k = 02a = 3 k = 0
Figure 3 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 ℎ = 01120596 = 5 119860 = 1 120596119905 = 120587
Grashof number is defined as the ratio of buoyancy forceto viscous force and its positive value identifies the flow pastan externally cooled plate and the negative value characterizesthe flow past an externally heated plate Figure 5 shows thatas Gr increases the resistance of fluid flow diminishes and asa consequence the speed enhances along with the increasingvalues of visco-elastic parameter Again when the flow passesan externally heated plate (Gr = minus10) a back flow is noticedin case of both Newtonian and non-Newtonian fluids
4 Results and Discussions
Knowing the velocity field it is important from a practicalpoint of view to know the effect of viscoelastic parameteron shearing stress or viscous drag Figures 6 to 8 depictthe magnitude of shearing stress at the plate of viscoelasticfluid in comparison with the Newtonian fluid for the variousvalues of flow parameters involved in the solution Thefigures notify that the growth in viscoelasticity subdues themagnitude of viscous drag at the surface Prandtl numberplays a significant role in heat transfer flow problems as it
0 2 4 6 8 10 120
05
1
15
2
25
3
35
u
y
M = 5 M = 3 M = 2 M = 1
Figure 4 Pr = 10 Sc = 7 Gm = 5 Gr = 10 119890 = 001 ℎ = 01 120596 = 5119860 = 1 120596119905 = 120587
minus3 minus2 minus1 0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
Gr = 7 Gr = 10Gr = minus10
Figure 5 Pr = 10 Sc = 7 Gm = 5 119890 = 001 ℎ = 01 120596 = 5 119860 = 1120596119905 = 120587119872 = 2
helps to study the simultaneous effect of momentum andthermal diffusion in fluid flow Effect of Prandtl number onthe magnitude of shearing stress is seen in Figure 6 and it canbe concluded that the magnitude of shearing stress increasesrapidly for Pr lt 8 of both Newtonian and non-Newtonianfluids but for higher values of Pr (gt8) it increases steadily Inmass transfer problems the importance of Schmidt numbercannot be neglected as it studies the combined effect ofmomentum and mass diffusion The same phenomenon asthat in case of growth in Prandtl number is experiencedagainst Schmidt number for various values of viscoelasticparameter (Figure 7) Effect of gravity modulation parameter119886 on the viscous drag is shown in Figure 8 and it is revealedthat as 119886 increases themagnitude of shearing stress increases
The rate of heat transfer and rate of mass transfer are notsignificantly affected by the presence of viscoelasticity of thegoverning fluid flow
5 Conclusions
From the present study we make the following conclusions
(i) Both Newtonian and non-Newtonian fluid flowsaccelerate asymptotically in the neighbourhood of theplate
(ii) Growth in viscoelasticity slows down the speed offluid flow
6 ISRN Applied Mathematics
55 6 65 7 75 8 85 9 9502468
101214161820
k = 0
k = 04k = 02
Magnitude of shearing stress
Pran
dtl n
umbe
r
Figure 6 Sc = 7 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
6 65 7 75 8 85 9 9502468
10121416
k = 0
k = 04k = 02
Magnitude of shearing stress
Schm
idt n
umbe
r
Figure 7 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
(iii) Effect of viscoelasticity is seen prominent during thelower order magnitude of magnetic parameter
(iv) A back flow is experienced in the motion governingfluid flow past an externally heated plate
(v) As gravity modulation parameter 119886 increases themagnitude of shearing stress experienced by Newto-nian as well as non-Newtonian fluid flows increase
Conflict of Interests
The author does not have any conflict of interests regardingthe publication of paper
Acknowledgment
Theauthor acknowledges Professor Rita Choudhury Depart-ment of Mathematics Gauhati University for her encourage-ment throughout this work
75 8 85 9 95 100
1
2
3
4
5
6
k = 0
k = 04k = 02
Magnitude of shearing stress
Gra
vity
mod
ulat
ion
para
met
er
Figure 8 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 Sc = 7 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
References
[1] R Siegel ldquoTransient-free convection from a vertical flat platerdquoTransactions of the American Society of Mechanical Engineersvol 80 pp 347ndash359 1958
[2] B Gebhart ldquoTransient natural convection from vertical ele-mentsrdquo Journal of Heat Transfer vol 83 pp 61ndash70 1961
[3] P M Chung and A D Anderson ldquoUnsteady laminar freeconvectionrdquo Journal of Heat Transfer vol 83 pp 474ndash478 1961
[4] J A Schetz and R Eichhorn ldquoUnsteady natural convection inthe vicinity of a doubly infinite vertical platerdquo Journal of HeatTransfer vol 84 pp 334ndash338 1962
[5] R J Goldstein and D G Briggs ldquoTransient-free convectionabout vertical plates and circular cylindersrdquo Journal of HeatTransfer vol 86 pp 490ndash500 1964
[6] R Clever G Schubert and F H Busse ldquoTwo-dimensionaloscillatory convection in a gravitationally modulated fluidlayerrdquo Journal of Fluid Mechanics vol 253 pp 663ndash680 1993
[7] R Clever G Schubert and F H Busse ldquoThree-dimensionaloscillatory convection in a gravitational modulated fluid layerrdquoPhysics of Fluids A vol 5 no 10 pp 2430ndash2437 1992
[8] W S Fu and W J Shieh ldquoA study of thermal convection inan enclosure induced simultaneously by gravity and vibrationrdquoInternational Journal of Heat and Mass Transfer vol 35 no 7pp 1695ndash1710 1992
[9] S Ostrach ldquoConvection phenomena of importance for materi-als processing in spacerdquo in Proceedings of the COSPAR Sympo-sium on Materials Sciences in Space pp 3ndash33 Philadelphia PaUSA 1976
[10] B Q Li ldquoThe effect of magnetic fields on low frequency oscil-lating natural convectionrdquo International Journal of EngineeringScience vol 34 no 12 pp 1369ndash1383 1996
[11] R K Deka and V M Soundalgekar ldquoGravity modulationeffects on transient-free convection flow past an infinite verticalisothermal platerdquoDefence Science Journal vol 56 no 4 pp 477ndash483 2006
[12] S C Rajvanshi and B S Saini ldquoFree convection MHD flowpast a moving vertical porous surface with gravity modulationat constant heat fluxrdquo International Journal of Theoretical andApplied Sciences vol 2 no 1 pp 29ndash33 2010
[13] S R Jain and S C Rajvanshi ldquoInfluence of gravity modulationviscous heating and concentration on flow past a vertical
ISRN Applied Mathematics 7
plate in slip flow regime with periodic temperature variationsrdquoInternational Journal of Theoretical and Applied Science vol 3no 1 pp 16ndash22 2011
[14] K Walter ldquoNon-Newtonian effects in some elastico-viscousliquids whose behavior at small rates of shear is characterizedby a general linear equation of staterdquo The Quarterly Journal ofMechanics and Applied Mathematics vol 15 pp 63ndash76 1962
[15] K R Crammer and S Pai Magneto-Fluid Dynamics for Engi-neers and Applied Physicist McGraw- Hill New York NY USA1973
[16] C L M H Navier Memoirs de LrsquoAcademie Royale des Sciencesde Lrsquoinstitut de France vol 1 1823
[17] T R Mahapatra and A S Gupta ldquoStagnation-point flow ofa viscoelastic fluid towards a stretching surfacerdquo InternationalJournal of Non-Linear Mechanics vol 39 no 5 pp 811ndash8202004
[18] M Reza and A S Gupta ldquoMomentum and heat transfer in theflow of a viscoelastic fluid past a porous flat plate subject tosuction or blowingrdquoWorld Academy of Science Engineering andTechnology vol 23 pp 960ndash963 2008
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
ISRN Applied Mathematics 3
Let us introduce the following nondimensional quantities
119910 =
11991010158401198810
] 119905 =
11990510158401198810
2
4] 120596 =
4]1205961015840
1198810
2
119906 =
1199061015840
1198810
120579 =
1198791015840minus 119879infin
119879119908minus 119879infin
119862 =
1198621015840minus 119862infin
119862119908minus 119862infin
Gr =1198920120573] (119879119908minus 119879infin)
1198810
3 Gr =
11989201205730] (119862119908minus 119862infin)
1198810
3
119872 =
1205901198612
0]
1205881198810
2 119896 =
11989601198810
2
120588]2
Pr =1205780119862119875
119870
Sc = ]119863
ℎ = ℎ10158401205881198812
0
(9)
where 119910 is the displacement variable 119905 is the time 120596 isthe frequency of oscillation 119906 is the dimension velocity 120579is the dimensionless temperature 119862 is the dimensionlessconcentration Gr is Grashof number for heat transfer Gm isGrashof number for mass transfer119872 is magnetic parameter119896 is viscoelastic parameter Pr is the Prandtl number Sc is theSchmidt number 119886 is gravity modulation parameter and ℎ isthe slip parameter
Then the nondimensional forms of the governing equa-tions of motions are as follows
1
4
120597119906
120597119905
minus (1 + 120598119860119890119894120596119905)
120597119906
120597119910
= (Gr120579 + Gm119862) (1 minus 119894120598120572119890119894120596119905) +
1205972119906
1205971199102minus119872119906
minus 119896[
1
4
1205973119906
1205971199102120597119905
minus (1 + 120598119860119890119894120596119905)
1205973119906
1205971199103]
1
4
120597120579
120597119905
minus (1 + 120598119860119890119894120596119905)
120597120579
120597119910
=
1
Pr1205972120579
1205971199102
1
4
120597119862
120597119905
minus (1 + 120598119860119890119894120596119905)
120597119862
120597119910
=
1
Pr1205972119862
1205971199102
(10)
Boundary conditions in the dimensionless form are given asfollows
119906 = ℎ [
120597119906
120597119910
minus 119896
1
4
1205972119906
120597119910120597119905
minus (1 + 120598119860119890119894120596119905)
1205972119906
1205971199102]
120579 = 1 + 120598119890119894120596119905 119862 = 1 + 120598119890
119894120596119905
at 119910 = 0
119906 997888rarr 0 120579 997888rarr 0 119862 997888rarr 0
as 119910 997888rarr infin
(11)
Assuming small amplitude of oscillations (120598 ≪ 1) in theneighbourhood of the plate the velocity temperature andconcentration are considered as
119906 = 1199060+ 1205981198901198941205961199051199061+ 119900 (120598
2)
120579 = 1205790+ 1205981198901198941205961199051205791+ 119900 (120598
2)
119862 = 1198620+ 1205981198901198941205961199051198621+ 119900 (120598
2)
(12)
Using (12) in (10) and equating the like powers of 120598 andneglecting the higher powers of 120598 we get
119896119906101584010158401015840
0+ 11990610158401015840
0+ 1199061015840
0minus119872119906
0= minus (Gr120579
0+ Gm119862
0)
119896119906101584010158401015840
1+ 11990610158401015840
1(1 minus 119896
119894120596
4
) + 1199061015840
1minus (119872 +
119894120596
4
) 1199061
= Gr (1205721205790minus 1205791) + Gm (120572119862
0minus 1198621)
minus 1198601199061015840
0minus 119896119860119906
101584010158401015840
0
(13)
1
Pr12057910158401015840
0+ 1205791015840
0= 0
1
Pr12057910158401015840
1+ 1205791015840
1minus
119894120596
4
1205791= minus1205791015840
0
1
Sc11986210158401015840
0+ 1198621015840
0= 0
1
Sc11986210158401015840
1+ 1198621015840
1minus
119894120596
4
1198621= minus1198621015840
0
(14)
Relevant boundary conditions for solving the above equa-tions are as follows
1199060= ℎ [119906
1015840
0+ 11989611990610158401015840
0]
1199061= ℎ [119906
1015840
1minus 119896
119894120596
4
1199061015840
1minus 11986011990610158401015840
0minus 11990610158401015840
1]
1205790= 1205791= 1198620= 1198621= 1
at 119910 = 0
1199060= 1199061= 1205790= 1205791= 1198620= 1198621= 0
as 119910 997888rarr infin
(15)
Equations (14) are solved by using the boundary conditions(15) and their solutions are given by
1205790= 119890minusPr119910
1205791= 11986231198901205721119910+ 1198624119890minus1205722119910+
1198944Pr120596
119890minusPr119910
1198620= 119890minusSc119910
1198621= 11986251198901205723119910+ 1198626119890minus1205724119910+
1198944Sc120596
119890minusSc119910
(16)
The presence of elasticity in the governing fluid motionconstitutes a third-order differential equation (13) but for
4 ISRN Applied Mathematics
Newtonian fluid 119896 = 0 then the differential equation redu-ces to of order two And also it is seen that as there areinsufficient boundary conditions for solving (13) we usemultiparameter perturbation technique Since 119896 which is ameasure (dimensionless) of relaxation time is very small fora viscoelastic fluid with small memory thus following RayMahapatra and Gupta [17] and Reza and Gupta [18] we usethe multiparameter perturbation technique and we consider
1199060= 11990600+ 11989611990601+ 119900 (119896
2)
1199061= 11990610+ 11989611990611+ 119900 (119896
2)
(17)
Using the perturbation scheme (17) in (13) and equating thelike powers of 119896 and neglecting the higher orders power of 119896we get
11990610158401015840
00+ 1199061015840
00minus119872119906
00= minus (Gr120579
0+ Gm119862
0)
11990610158401015840
00+ 1199061015840
00minus119872119906
00= minus119906101584010158401015840
00
11990610158401015840
10+ 1199061015840
10minus (119872 +
119894120596
4
) 11990610
= 120572 (Gr1205790+ Gm119862
0) minus 119860119906
1015840
0minus (Gr120579
1+ Gm119862
1)
11990610158401015840
11+ 1199061015840
11minus (119872 +
119894120596
4
) 11990611
= minus1198601199061015840
01minus 119860119906101584010158401015840
00minus 119906101584010158401015840
10minus
119894120596
4
11990610158401015840
10
(18)
The modified boundary conditions for solving the aboveequations are
11990600= ℎ1199061015840
00 119906
01= ℎ [119906
1015840
01+ 11990610158401015840
00] 119906
10= ℎ1199061015840
10
11990611= ℎ [119906
1015840
11minus
119894120596
4
1199061015840
10+ 11986011990610158401015840
00+ 11990610158401015840
10]
at 119910 = 0
11990600997888rarr 0 119906
01997888rarr 0 119906
10997888rarr 0 119906
11997888rarr 0
as 119910 997888rarr infin
(19)
The solutions of (18) relevant to the above boundary condi-tions are presented as follows
11990600= 1198628119890minus1205726119910+ 1198601119890minus1198601119910+ 1198602119890minus1198602119910
11990601= 11986210119890minus1205726119910+ 1198603119910119890minus1205726119910+ 1198604119890minus1198601119910+ 1198605119890minus1198602119910
11990610= 11986212119890minus1205728119910+ (1198606+ 1198941198607) 119890minusPr119910
+ (1198608+ 1198941198609) 119890minusSc119910
+ 11989411986010119890minus1205726119910
+ (11986011+ 11989411986012) 119890minus1198601119910+ (11986013+ 11989411986014) 119890minus1198602119910
+ (11986015+ 11989411986016) 119890minus1205722119910+ (11986017+ 11989411986018) 119890minus1205724119910
11990610= 11986214119890minus1205728119910+ (11986036+ 11989411986037) 119890minus1205726119910+ 11989411986038119910119890minus1205726119910
+ (11986039+ 11989411986040) 119890minus1198601119910+ (11986041+ 11989411986042) 119890minus1198602119910
+ (11986043+ 11989411986044) 119910119890minus1205728119910+ (11986045+ 11989411986046) 119890minusPr119910
+ (11986047+ 11989411986048) 119890minusSc119910
+ (11986049+ 11989411986050) 119890minus1205722119910
+ (11986051+ 11989411986052) 119890minus1205724119910
(20)
The constants of the solutions are not presented here for thesake of brevity
Knowing the velocity field the shearing stress at the plateis defined as
Sh = [
120597119906
120597119910
minus 119896
1
4
1205972119906
120597119910120597119905
minus (1 + 120598119860119890119894120596119905)
1205972119906
1205971199102]
119910=0
(21)
The effects of gravity modulation on free convectiveflow of an elastico-viscous fluid with simultaneous heat andmass transfer past an infinite vertical porous plate under theinfluence of transverse magnetic field have been analyzedFigures 2 to 5 represent the pattern of velocity profile against119910 for various values of flow parameters involved in thesolution The effect of viscoelasticity is exhibited throughthe nondimensional parameter ldquo119896rdquo The nonzero values of119896 characterize viscoelastic fluid where 119896 = 0 character-izes Newtonian fluid flow mechanisms In this study mainemphasis is given on the effect of viscoelasticity on thegoverning fluid motion and also on the difference in flowpattern of both Newtonian and non-Newtonian fluids in thepresence of various physical properties considered in thisproblem
It is seen from Figure 2 that both Newtonian and non-Newtonian fluid flows accelerate asymptotically in the neigh-bourhood of the plate and then they experience a declinetrend as we move away from the plate The nonzero value ofvelocity profile at 119910 = 0 represents the strength of slip at theplate Also it can be concluded that the growth in viscoelas-ticity slows down the speed of fluid flow Effects of gravitymodulation parameter 119886 on the governing fluid motions areshown in Figure 3 and it is observed that as 119886 increases thespeed of fluid flow increases along with the increasing valuesof 119896 = (0 02 and 04) Application of transverse magneticfield leads to the generalization of Lorentz force and its effectis displayed by the nondimensional parameter 119872 Figure 4shows the impact of magnetic parameter on the fluid flowagainst the displacement variable 119910 As magnetic parameterincreases the strength of Lorentz force rises and as a resultthe flow is retarded It is also noticed that as119872 decreases theeffect of viscoelasticity is seen prominent
ISRN Applied Mathematics 5
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
k = 0
k = 04k = 02
Figure 2 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 119886 = 1ℎ = 01 120596 = 5 119860 = 1 120596119905 = 120587
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
a = 1 k = 0a = 1 k = 02a = 1 k = 0
a = 3 k = 04a = 3 k = 02a = 3 k = 0
Figure 3 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 ℎ = 01120596 = 5 119860 = 1 120596119905 = 120587
Grashof number is defined as the ratio of buoyancy forceto viscous force and its positive value identifies the flow pastan externally cooled plate and the negative value characterizesthe flow past an externally heated plate Figure 5 shows thatas Gr increases the resistance of fluid flow diminishes and asa consequence the speed enhances along with the increasingvalues of visco-elastic parameter Again when the flow passesan externally heated plate (Gr = minus10) a back flow is noticedin case of both Newtonian and non-Newtonian fluids
4 Results and Discussions
Knowing the velocity field it is important from a practicalpoint of view to know the effect of viscoelastic parameteron shearing stress or viscous drag Figures 6 to 8 depictthe magnitude of shearing stress at the plate of viscoelasticfluid in comparison with the Newtonian fluid for the variousvalues of flow parameters involved in the solution Thefigures notify that the growth in viscoelasticity subdues themagnitude of viscous drag at the surface Prandtl numberplays a significant role in heat transfer flow problems as it
0 2 4 6 8 10 120
05
1
15
2
25
3
35
u
y
M = 5 M = 3 M = 2 M = 1
Figure 4 Pr = 10 Sc = 7 Gm = 5 Gr = 10 119890 = 001 ℎ = 01 120596 = 5119860 = 1 120596119905 = 120587
minus3 minus2 minus1 0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
Gr = 7 Gr = 10Gr = minus10
Figure 5 Pr = 10 Sc = 7 Gm = 5 119890 = 001 ℎ = 01 120596 = 5 119860 = 1120596119905 = 120587119872 = 2
helps to study the simultaneous effect of momentum andthermal diffusion in fluid flow Effect of Prandtl number onthe magnitude of shearing stress is seen in Figure 6 and it canbe concluded that the magnitude of shearing stress increasesrapidly for Pr lt 8 of both Newtonian and non-Newtonianfluids but for higher values of Pr (gt8) it increases steadily Inmass transfer problems the importance of Schmidt numbercannot be neglected as it studies the combined effect ofmomentum and mass diffusion The same phenomenon asthat in case of growth in Prandtl number is experiencedagainst Schmidt number for various values of viscoelasticparameter (Figure 7) Effect of gravity modulation parameter119886 on the viscous drag is shown in Figure 8 and it is revealedthat as 119886 increases themagnitude of shearing stress increases
The rate of heat transfer and rate of mass transfer are notsignificantly affected by the presence of viscoelasticity of thegoverning fluid flow
5 Conclusions
From the present study we make the following conclusions
(i) Both Newtonian and non-Newtonian fluid flowsaccelerate asymptotically in the neighbourhood of theplate
(ii) Growth in viscoelasticity slows down the speed offluid flow
6 ISRN Applied Mathematics
55 6 65 7 75 8 85 9 9502468
101214161820
k = 0
k = 04k = 02
Magnitude of shearing stress
Pran
dtl n
umbe
r
Figure 6 Sc = 7 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
6 65 7 75 8 85 9 9502468
10121416
k = 0
k = 04k = 02
Magnitude of shearing stress
Schm
idt n
umbe
r
Figure 7 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
(iii) Effect of viscoelasticity is seen prominent during thelower order magnitude of magnetic parameter
(iv) A back flow is experienced in the motion governingfluid flow past an externally heated plate
(v) As gravity modulation parameter 119886 increases themagnitude of shearing stress experienced by Newto-nian as well as non-Newtonian fluid flows increase
Conflict of Interests
The author does not have any conflict of interests regardingthe publication of paper
Acknowledgment
Theauthor acknowledges Professor Rita Choudhury Depart-ment of Mathematics Gauhati University for her encourage-ment throughout this work
75 8 85 9 95 100
1
2
3
4
5
6
k = 0
k = 04k = 02
Magnitude of shearing stress
Gra
vity
mod
ulat
ion
para
met
er
Figure 8 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 Sc = 7 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
References
[1] R Siegel ldquoTransient-free convection from a vertical flat platerdquoTransactions of the American Society of Mechanical Engineersvol 80 pp 347ndash359 1958
[2] B Gebhart ldquoTransient natural convection from vertical ele-mentsrdquo Journal of Heat Transfer vol 83 pp 61ndash70 1961
[3] P M Chung and A D Anderson ldquoUnsteady laminar freeconvectionrdquo Journal of Heat Transfer vol 83 pp 474ndash478 1961
[4] J A Schetz and R Eichhorn ldquoUnsteady natural convection inthe vicinity of a doubly infinite vertical platerdquo Journal of HeatTransfer vol 84 pp 334ndash338 1962
[5] R J Goldstein and D G Briggs ldquoTransient-free convectionabout vertical plates and circular cylindersrdquo Journal of HeatTransfer vol 86 pp 490ndash500 1964
[6] R Clever G Schubert and F H Busse ldquoTwo-dimensionaloscillatory convection in a gravitationally modulated fluidlayerrdquo Journal of Fluid Mechanics vol 253 pp 663ndash680 1993
[7] R Clever G Schubert and F H Busse ldquoThree-dimensionaloscillatory convection in a gravitational modulated fluid layerrdquoPhysics of Fluids A vol 5 no 10 pp 2430ndash2437 1992
[8] W S Fu and W J Shieh ldquoA study of thermal convection inan enclosure induced simultaneously by gravity and vibrationrdquoInternational Journal of Heat and Mass Transfer vol 35 no 7pp 1695ndash1710 1992
[9] S Ostrach ldquoConvection phenomena of importance for materi-als processing in spacerdquo in Proceedings of the COSPAR Sympo-sium on Materials Sciences in Space pp 3ndash33 Philadelphia PaUSA 1976
[10] B Q Li ldquoThe effect of magnetic fields on low frequency oscil-lating natural convectionrdquo International Journal of EngineeringScience vol 34 no 12 pp 1369ndash1383 1996
[11] R K Deka and V M Soundalgekar ldquoGravity modulationeffects on transient-free convection flow past an infinite verticalisothermal platerdquoDefence Science Journal vol 56 no 4 pp 477ndash483 2006
[12] S C Rajvanshi and B S Saini ldquoFree convection MHD flowpast a moving vertical porous surface with gravity modulationat constant heat fluxrdquo International Journal of Theoretical andApplied Sciences vol 2 no 1 pp 29ndash33 2010
[13] S R Jain and S C Rajvanshi ldquoInfluence of gravity modulationviscous heating and concentration on flow past a vertical
ISRN Applied Mathematics 7
plate in slip flow regime with periodic temperature variationsrdquoInternational Journal of Theoretical and Applied Science vol 3no 1 pp 16ndash22 2011
[14] K Walter ldquoNon-Newtonian effects in some elastico-viscousliquids whose behavior at small rates of shear is characterizedby a general linear equation of staterdquo The Quarterly Journal ofMechanics and Applied Mathematics vol 15 pp 63ndash76 1962
[15] K R Crammer and S Pai Magneto-Fluid Dynamics for Engi-neers and Applied Physicist McGraw- Hill New York NY USA1973
[16] C L M H Navier Memoirs de LrsquoAcademie Royale des Sciencesde Lrsquoinstitut de France vol 1 1823
[17] T R Mahapatra and A S Gupta ldquoStagnation-point flow ofa viscoelastic fluid towards a stretching surfacerdquo InternationalJournal of Non-Linear Mechanics vol 39 no 5 pp 811ndash8202004
[18] M Reza and A S Gupta ldquoMomentum and heat transfer in theflow of a viscoelastic fluid past a porous flat plate subject tosuction or blowingrdquoWorld Academy of Science Engineering andTechnology vol 23 pp 960ndash963 2008
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
4 ISRN Applied Mathematics
Newtonian fluid 119896 = 0 then the differential equation redu-ces to of order two And also it is seen that as there areinsufficient boundary conditions for solving (13) we usemultiparameter perturbation technique Since 119896 which is ameasure (dimensionless) of relaxation time is very small fora viscoelastic fluid with small memory thus following RayMahapatra and Gupta [17] and Reza and Gupta [18] we usethe multiparameter perturbation technique and we consider
1199060= 11990600+ 11989611990601+ 119900 (119896
2)
1199061= 11990610+ 11989611990611+ 119900 (119896
2)
(17)
Using the perturbation scheme (17) in (13) and equating thelike powers of 119896 and neglecting the higher orders power of 119896we get
11990610158401015840
00+ 1199061015840
00minus119872119906
00= minus (Gr120579
0+ Gm119862
0)
11990610158401015840
00+ 1199061015840
00minus119872119906
00= minus119906101584010158401015840
00
11990610158401015840
10+ 1199061015840
10minus (119872 +
119894120596
4
) 11990610
= 120572 (Gr1205790+ Gm119862
0) minus 119860119906
1015840
0minus (Gr120579
1+ Gm119862
1)
11990610158401015840
11+ 1199061015840
11minus (119872 +
119894120596
4
) 11990611
= minus1198601199061015840
01minus 119860119906101584010158401015840
00minus 119906101584010158401015840
10minus
119894120596
4
11990610158401015840
10
(18)
The modified boundary conditions for solving the aboveequations are
11990600= ℎ1199061015840
00 119906
01= ℎ [119906
1015840
01+ 11990610158401015840
00] 119906
10= ℎ1199061015840
10
11990611= ℎ [119906
1015840
11minus
119894120596
4
1199061015840
10+ 11986011990610158401015840
00+ 11990610158401015840
10]
at 119910 = 0
11990600997888rarr 0 119906
01997888rarr 0 119906
10997888rarr 0 119906
11997888rarr 0
as 119910 997888rarr infin
(19)
The solutions of (18) relevant to the above boundary condi-tions are presented as follows
11990600= 1198628119890minus1205726119910+ 1198601119890minus1198601119910+ 1198602119890minus1198602119910
11990601= 11986210119890minus1205726119910+ 1198603119910119890minus1205726119910+ 1198604119890minus1198601119910+ 1198605119890minus1198602119910
11990610= 11986212119890minus1205728119910+ (1198606+ 1198941198607) 119890minusPr119910
+ (1198608+ 1198941198609) 119890minusSc119910
+ 11989411986010119890minus1205726119910
+ (11986011+ 11989411986012) 119890minus1198601119910+ (11986013+ 11989411986014) 119890minus1198602119910
+ (11986015+ 11989411986016) 119890minus1205722119910+ (11986017+ 11989411986018) 119890minus1205724119910
11990610= 11986214119890minus1205728119910+ (11986036+ 11989411986037) 119890minus1205726119910+ 11989411986038119910119890minus1205726119910
+ (11986039+ 11989411986040) 119890minus1198601119910+ (11986041+ 11989411986042) 119890minus1198602119910
+ (11986043+ 11989411986044) 119910119890minus1205728119910+ (11986045+ 11989411986046) 119890minusPr119910
+ (11986047+ 11989411986048) 119890minusSc119910
+ (11986049+ 11989411986050) 119890minus1205722119910
+ (11986051+ 11989411986052) 119890minus1205724119910
(20)
The constants of the solutions are not presented here for thesake of brevity
Knowing the velocity field the shearing stress at the plateis defined as
Sh = [
120597119906
120597119910
minus 119896
1
4
1205972119906
120597119910120597119905
minus (1 + 120598119860119890119894120596119905)
1205972119906
1205971199102]
119910=0
(21)
The effects of gravity modulation on free convectiveflow of an elastico-viscous fluid with simultaneous heat andmass transfer past an infinite vertical porous plate under theinfluence of transverse magnetic field have been analyzedFigures 2 to 5 represent the pattern of velocity profile against119910 for various values of flow parameters involved in thesolution The effect of viscoelasticity is exhibited throughthe nondimensional parameter ldquo119896rdquo The nonzero values of119896 characterize viscoelastic fluid where 119896 = 0 character-izes Newtonian fluid flow mechanisms In this study mainemphasis is given on the effect of viscoelasticity on thegoverning fluid motion and also on the difference in flowpattern of both Newtonian and non-Newtonian fluids in thepresence of various physical properties considered in thisproblem
It is seen from Figure 2 that both Newtonian and non-Newtonian fluid flows accelerate asymptotically in the neigh-bourhood of the plate and then they experience a declinetrend as we move away from the plate The nonzero value ofvelocity profile at 119910 = 0 represents the strength of slip at theplate Also it can be concluded that the growth in viscoelas-ticity slows down the speed of fluid flow Effects of gravitymodulation parameter 119886 on the governing fluid motions areshown in Figure 3 and it is observed that as 119886 increases thespeed of fluid flow increases along with the increasing valuesof 119896 = (0 02 and 04) Application of transverse magneticfield leads to the generalization of Lorentz force and its effectis displayed by the nondimensional parameter 119872 Figure 4shows the impact of magnetic parameter on the fluid flowagainst the displacement variable 119910 As magnetic parameterincreases the strength of Lorentz force rises and as a resultthe flow is retarded It is also noticed that as119872 decreases theeffect of viscoelasticity is seen prominent
ISRN Applied Mathematics 5
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
k = 0
k = 04k = 02
Figure 2 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 119886 = 1ℎ = 01 120596 = 5 119860 = 1 120596119905 = 120587
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
a = 1 k = 0a = 1 k = 02a = 1 k = 0
a = 3 k = 04a = 3 k = 02a = 3 k = 0
Figure 3 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 ℎ = 01120596 = 5 119860 = 1 120596119905 = 120587
Grashof number is defined as the ratio of buoyancy forceto viscous force and its positive value identifies the flow pastan externally cooled plate and the negative value characterizesthe flow past an externally heated plate Figure 5 shows thatas Gr increases the resistance of fluid flow diminishes and asa consequence the speed enhances along with the increasingvalues of visco-elastic parameter Again when the flow passesan externally heated plate (Gr = minus10) a back flow is noticedin case of both Newtonian and non-Newtonian fluids
4 Results and Discussions
Knowing the velocity field it is important from a practicalpoint of view to know the effect of viscoelastic parameteron shearing stress or viscous drag Figures 6 to 8 depictthe magnitude of shearing stress at the plate of viscoelasticfluid in comparison with the Newtonian fluid for the variousvalues of flow parameters involved in the solution Thefigures notify that the growth in viscoelasticity subdues themagnitude of viscous drag at the surface Prandtl numberplays a significant role in heat transfer flow problems as it
0 2 4 6 8 10 120
05
1
15
2
25
3
35
u
y
M = 5 M = 3 M = 2 M = 1
Figure 4 Pr = 10 Sc = 7 Gm = 5 Gr = 10 119890 = 001 ℎ = 01 120596 = 5119860 = 1 120596119905 = 120587
minus3 minus2 minus1 0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
Gr = 7 Gr = 10Gr = minus10
Figure 5 Pr = 10 Sc = 7 Gm = 5 119890 = 001 ℎ = 01 120596 = 5 119860 = 1120596119905 = 120587119872 = 2
helps to study the simultaneous effect of momentum andthermal diffusion in fluid flow Effect of Prandtl number onthe magnitude of shearing stress is seen in Figure 6 and it canbe concluded that the magnitude of shearing stress increasesrapidly for Pr lt 8 of both Newtonian and non-Newtonianfluids but for higher values of Pr (gt8) it increases steadily Inmass transfer problems the importance of Schmidt numbercannot be neglected as it studies the combined effect ofmomentum and mass diffusion The same phenomenon asthat in case of growth in Prandtl number is experiencedagainst Schmidt number for various values of viscoelasticparameter (Figure 7) Effect of gravity modulation parameter119886 on the viscous drag is shown in Figure 8 and it is revealedthat as 119886 increases themagnitude of shearing stress increases
The rate of heat transfer and rate of mass transfer are notsignificantly affected by the presence of viscoelasticity of thegoverning fluid flow
5 Conclusions
From the present study we make the following conclusions
(i) Both Newtonian and non-Newtonian fluid flowsaccelerate asymptotically in the neighbourhood of theplate
(ii) Growth in viscoelasticity slows down the speed offluid flow
6 ISRN Applied Mathematics
55 6 65 7 75 8 85 9 9502468
101214161820
k = 0
k = 04k = 02
Magnitude of shearing stress
Pran
dtl n
umbe
r
Figure 6 Sc = 7 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
6 65 7 75 8 85 9 9502468
10121416
k = 0
k = 04k = 02
Magnitude of shearing stress
Schm
idt n
umbe
r
Figure 7 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
(iii) Effect of viscoelasticity is seen prominent during thelower order magnitude of magnetic parameter
(iv) A back flow is experienced in the motion governingfluid flow past an externally heated plate
(v) As gravity modulation parameter 119886 increases themagnitude of shearing stress experienced by Newto-nian as well as non-Newtonian fluid flows increase
Conflict of Interests
The author does not have any conflict of interests regardingthe publication of paper
Acknowledgment
Theauthor acknowledges Professor Rita Choudhury Depart-ment of Mathematics Gauhati University for her encourage-ment throughout this work
75 8 85 9 95 100
1
2
3
4
5
6
k = 0
k = 04k = 02
Magnitude of shearing stress
Gra
vity
mod
ulat
ion
para
met
er
Figure 8 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 Sc = 7 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
References
[1] R Siegel ldquoTransient-free convection from a vertical flat platerdquoTransactions of the American Society of Mechanical Engineersvol 80 pp 347ndash359 1958
[2] B Gebhart ldquoTransient natural convection from vertical ele-mentsrdquo Journal of Heat Transfer vol 83 pp 61ndash70 1961
[3] P M Chung and A D Anderson ldquoUnsteady laminar freeconvectionrdquo Journal of Heat Transfer vol 83 pp 474ndash478 1961
[4] J A Schetz and R Eichhorn ldquoUnsteady natural convection inthe vicinity of a doubly infinite vertical platerdquo Journal of HeatTransfer vol 84 pp 334ndash338 1962
[5] R J Goldstein and D G Briggs ldquoTransient-free convectionabout vertical plates and circular cylindersrdquo Journal of HeatTransfer vol 86 pp 490ndash500 1964
[6] R Clever G Schubert and F H Busse ldquoTwo-dimensionaloscillatory convection in a gravitationally modulated fluidlayerrdquo Journal of Fluid Mechanics vol 253 pp 663ndash680 1993
[7] R Clever G Schubert and F H Busse ldquoThree-dimensionaloscillatory convection in a gravitational modulated fluid layerrdquoPhysics of Fluids A vol 5 no 10 pp 2430ndash2437 1992
[8] W S Fu and W J Shieh ldquoA study of thermal convection inan enclosure induced simultaneously by gravity and vibrationrdquoInternational Journal of Heat and Mass Transfer vol 35 no 7pp 1695ndash1710 1992
[9] S Ostrach ldquoConvection phenomena of importance for materi-als processing in spacerdquo in Proceedings of the COSPAR Sympo-sium on Materials Sciences in Space pp 3ndash33 Philadelphia PaUSA 1976
[10] B Q Li ldquoThe effect of magnetic fields on low frequency oscil-lating natural convectionrdquo International Journal of EngineeringScience vol 34 no 12 pp 1369ndash1383 1996
[11] R K Deka and V M Soundalgekar ldquoGravity modulationeffects on transient-free convection flow past an infinite verticalisothermal platerdquoDefence Science Journal vol 56 no 4 pp 477ndash483 2006
[12] S C Rajvanshi and B S Saini ldquoFree convection MHD flowpast a moving vertical porous surface with gravity modulationat constant heat fluxrdquo International Journal of Theoretical andApplied Sciences vol 2 no 1 pp 29ndash33 2010
[13] S R Jain and S C Rajvanshi ldquoInfluence of gravity modulationviscous heating and concentration on flow past a vertical
ISRN Applied Mathematics 7
plate in slip flow regime with periodic temperature variationsrdquoInternational Journal of Theoretical and Applied Science vol 3no 1 pp 16ndash22 2011
[14] K Walter ldquoNon-Newtonian effects in some elastico-viscousliquids whose behavior at small rates of shear is characterizedby a general linear equation of staterdquo The Quarterly Journal ofMechanics and Applied Mathematics vol 15 pp 63ndash76 1962
[15] K R Crammer and S Pai Magneto-Fluid Dynamics for Engi-neers and Applied Physicist McGraw- Hill New York NY USA1973
[16] C L M H Navier Memoirs de LrsquoAcademie Royale des Sciencesde Lrsquoinstitut de France vol 1 1823
[17] T R Mahapatra and A S Gupta ldquoStagnation-point flow ofa viscoelastic fluid towards a stretching surfacerdquo InternationalJournal of Non-Linear Mechanics vol 39 no 5 pp 811ndash8202004
[18] M Reza and A S Gupta ldquoMomentum and heat transfer in theflow of a viscoelastic fluid past a porous flat plate subject tosuction or blowingrdquoWorld Academy of Science Engineering andTechnology vol 23 pp 960ndash963 2008
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
ISRN Applied Mathematics 5
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
k = 0
k = 04k = 02
Figure 2 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 119886 = 1ℎ = 01 120596 = 5 119860 = 1 120596119905 = 120587
0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
a = 1 k = 0a = 1 k = 02a = 1 k = 0
a = 3 k = 04a = 3 k = 02a = 3 k = 0
Figure 3 Pr = 10 Sc = 7 Gm = 5 Gr = 10119872 = 2 119890 = 001 ℎ = 01120596 = 5 119860 = 1 120596119905 = 120587
Grashof number is defined as the ratio of buoyancy forceto viscous force and its positive value identifies the flow pastan externally cooled plate and the negative value characterizesthe flow past an externally heated plate Figure 5 shows thatas Gr increases the resistance of fluid flow diminishes and asa consequence the speed enhances along with the increasingvalues of visco-elastic parameter Again when the flow passesan externally heated plate (Gr = minus10) a back flow is noticedin case of both Newtonian and non-Newtonian fluids
4 Results and Discussions
Knowing the velocity field it is important from a practicalpoint of view to know the effect of viscoelastic parameteron shearing stress or viscous drag Figures 6 to 8 depictthe magnitude of shearing stress at the plate of viscoelasticfluid in comparison with the Newtonian fluid for the variousvalues of flow parameters involved in the solution Thefigures notify that the growth in viscoelasticity subdues themagnitude of viscous drag at the surface Prandtl numberplays a significant role in heat transfer flow problems as it
0 2 4 6 8 10 120
05
1
15
2
25
3
35
u
y
M = 5 M = 3 M = 2 M = 1
Figure 4 Pr = 10 Sc = 7 Gm = 5 Gr = 10 119890 = 001 ℎ = 01 120596 = 5119860 = 1 120596119905 = 120587
minus3 minus2 minus1 0 1 2 3 4 5 6 70
05
1
15
2
25
3
35
u
y
Gr = 7 Gr = 10Gr = minus10
Figure 5 Pr = 10 Sc = 7 Gm = 5 119890 = 001 ℎ = 01 120596 = 5 119860 = 1120596119905 = 120587119872 = 2
helps to study the simultaneous effect of momentum andthermal diffusion in fluid flow Effect of Prandtl number onthe magnitude of shearing stress is seen in Figure 6 and it canbe concluded that the magnitude of shearing stress increasesrapidly for Pr lt 8 of both Newtonian and non-Newtonianfluids but for higher values of Pr (gt8) it increases steadily Inmass transfer problems the importance of Schmidt numbercannot be neglected as it studies the combined effect ofmomentum and mass diffusion The same phenomenon asthat in case of growth in Prandtl number is experiencedagainst Schmidt number for various values of viscoelasticparameter (Figure 7) Effect of gravity modulation parameter119886 on the viscous drag is shown in Figure 8 and it is revealedthat as 119886 increases themagnitude of shearing stress increases
The rate of heat transfer and rate of mass transfer are notsignificantly affected by the presence of viscoelasticity of thegoverning fluid flow
5 Conclusions
From the present study we make the following conclusions
(i) Both Newtonian and non-Newtonian fluid flowsaccelerate asymptotically in the neighbourhood of theplate
(ii) Growth in viscoelasticity slows down the speed offluid flow
6 ISRN Applied Mathematics
55 6 65 7 75 8 85 9 9502468
101214161820
k = 0
k = 04k = 02
Magnitude of shearing stress
Pran
dtl n
umbe
r
Figure 6 Sc = 7 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
6 65 7 75 8 85 9 9502468
10121416
k = 0
k = 04k = 02
Magnitude of shearing stress
Schm
idt n
umbe
r
Figure 7 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
(iii) Effect of viscoelasticity is seen prominent during thelower order magnitude of magnetic parameter
(iv) A back flow is experienced in the motion governingfluid flow past an externally heated plate
(v) As gravity modulation parameter 119886 increases themagnitude of shearing stress experienced by Newto-nian as well as non-Newtonian fluid flows increase
Conflict of Interests
The author does not have any conflict of interests regardingthe publication of paper
Acknowledgment
Theauthor acknowledges Professor Rita Choudhury Depart-ment of Mathematics Gauhati University for her encourage-ment throughout this work
75 8 85 9 95 100
1
2
3
4
5
6
k = 0
k = 04k = 02
Magnitude of shearing stress
Gra
vity
mod
ulat
ion
para
met
er
Figure 8 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 Sc = 7 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
References
[1] R Siegel ldquoTransient-free convection from a vertical flat platerdquoTransactions of the American Society of Mechanical Engineersvol 80 pp 347ndash359 1958
[2] B Gebhart ldquoTransient natural convection from vertical ele-mentsrdquo Journal of Heat Transfer vol 83 pp 61ndash70 1961
[3] P M Chung and A D Anderson ldquoUnsteady laminar freeconvectionrdquo Journal of Heat Transfer vol 83 pp 474ndash478 1961
[4] J A Schetz and R Eichhorn ldquoUnsteady natural convection inthe vicinity of a doubly infinite vertical platerdquo Journal of HeatTransfer vol 84 pp 334ndash338 1962
[5] R J Goldstein and D G Briggs ldquoTransient-free convectionabout vertical plates and circular cylindersrdquo Journal of HeatTransfer vol 86 pp 490ndash500 1964
[6] R Clever G Schubert and F H Busse ldquoTwo-dimensionaloscillatory convection in a gravitationally modulated fluidlayerrdquo Journal of Fluid Mechanics vol 253 pp 663ndash680 1993
[7] R Clever G Schubert and F H Busse ldquoThree-dimensionaloscillatory convection in a gravitational modulated fluid layerrdquoPhysics of Fluids A vol 5 no 10 pp 2430ndash2437 1992
[8] W S Fu and W J Shieh ldquoA study of thermal convection inan enclosure induced simultaneously by gravity and vibrationrdquoInternational Journal of Heat and Mass Transfer vol 35 no 7pp 1695ndash1710 1992
[9] S Ostrach ldquoConvection phenomena of importance for materi-als processing in spacerdquo in Proceedings of the COSPAR Sympo-sium on Materials Sciences in Space pp 3ndash33 Philadelphia PaUSA 1976
[10] B Q Li ldquoThe effect of magnetic fields on low frequency oscil-lating natural convectionrdquo International Journal of EngineeringScience vol 34 no 12 pp 1369ndash1383 1996
[11] R K Deka and V M Soundalgekar ldquoGravity modulationeffects on transient-free convection flow past an infinite verticalisothermal platerdquoDefence Science Journal vol 56 no 4 pp 477ndash483 2006
[12] S C Rajvanshi and B S Saini ldquoFree convection MHD flowpast a moving vertical porous surface with gravity modulationat constant heat fluxrdquo International Journal of Theoretical andApplied Sciences vol 2 no 1 pp 29ndash33 2010
[13] S R Jain and S C Rajvanshi ldquoInfluence of gravity modulationviscous heating and concentration on flow past a vertical
ISRN Applied Mathematics 7
plate in slip flow regime with periodic temperature variationsrdquoInternational Journal of Theoretical and Applied Science vol 3no 1 pp 16ndash22 2011
[14] K Walter ldquoNon-Newtonian effects in some elastico-viscousliquids whose behavior at small rates of shear is characterizedby a general linear equation of staterdquo The Quarterly Journal ofMechanics and Applied Mathematics vol 15 pp 63ndash76 1962
[15] K R Crammer and S Pai Magneto-Fluid Dynamics for Engi-neers and Applied Physicist McGraw- Hill New York NY USA1973
[16] C L M H Navier Memoirs de LrsquoAcademie Royale des Sciencesde Lrsquoinstitut de France vol 1 1823
[17] T R Mahapatra and A S Gupta ldquoStagnation-point flow ofa viscoelastic fluid towards a stretching surfacerdquo InternationalJournal of Non-Linear Mechanics vol 39 no 5 pp 811ndash8202004
[18] M Reza and A S Gupta ldquoMomentum and heat transfer in theflow of a viscoelastic fluid past a porous flat plate subject tosuction or blowingrdquoWorld Academy of Science Engineering andTechnology vol 23 pp 960ndash963 2008
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
6 ISRN Applied Mathematics
55 6 65 7 75 8 85 9 9502468
101214161820
k = 0
k = 04k = 02
Magnitude of shearing stress
Pran
dtl n
umbe
r
Figure 6 Sc = 7 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
6 65 7 75 8 85 9 9502468
10121416
k = 0
k = 04k = 02
Magnitude of shearing stress
Schm
idt n
umbe
r
Figure 7 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 119886 = 1 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
(iii) Effect of viscoelasticity is seen prominent during thelower order magnitude of magnetic parameter
(iv) A back flow is experienced in the motion governingfluid flow past an externally heated plate
(v) As gravity modulation parameter 119886 increases themagnitude of shearing stress experienced by Newto-nian as well as non-Newtonian fluid flows increase
Conflict of Interests
The author does not have any conflict of interests regardingthe publication of paper
Acknowledgment
Theauthor acknowledges Professor Rita Choudhury Depart-ment of Mathematics Gauhati University for her encourage-ment throughout this work
75 8 85 9 95 100
1
2
3
4
5
6
k = 0
k = 04k = 02
Magnitude of shearing stress
Gra
vity
mod
ulat
ion
para
met
er
Figure 8 Pr = 10 Gm = 10 Gr = 7119872 = 2 119890 = 001 Sc = 7 ℎ = 03120596 = 5 119860 = 6 120596119905 = 120587
References
[1] R Siegel ldquoTransient-free convection from a vertical flat platerdquoTransactions of the American Society of Mechanical Engineersvol 80 pp 347ndash359 1958
[2] B Gebhart ldquoTransient natural convection from vertical ele-mentsrdquo Journal of Heat Transfer vol 83 pp 61ndash70 1961
[3] P M Chung and A D Anderson ldquoUnsteady laminar freeconvectionrdquo Journal of Heat Transfer vol 83 pp 474ndash478 1961
[4] J A Schetz and R Eichhorn ldquoUnsteady natural convection inthe vicinity of a doubly infinite vertical platerdquo Journal of HeatTransfer vol 84 pp 334ndash338 1962
[5] R J Goldstein and D G Briggs ldquoTransient-free convectionabout vertical plates and circular cylindersrdquo Journal of HeatTransfer vol 86 pp 490ndash500 1964
[6] R Clever G Schubert and F H Busse ldquoTwo-dimensionaloscillatory convection in a gravitationally modulated fluidlayerrdquo Journal of Fluid Mechanics vol 253 pp 663ndash680 1993
[7] R Clever G Schubert and F H Busse ldquoThree-dimensionaloscillatory convection in a gravitational modulated fluid layerrdquoPhysics of Fluids A vol 5 no 10 pp 2430ndash2437 1992
[8] W S Fu and W J Shieh ldquoA study of thermal convection inan enclosure induced simultaneously by gravity and vibrationrdquoInternational Journal of Heat and Mass Transfer vol 35 no 7pp 1695ndash1710 1992
[9] S Ostrach ldquoConvection phenomena of importance for materi-als processing in spacerdquo in Proceedings of the COSPAR Sympo-sium on Materials Sciences in Space pp 3ndash33 Philadelphia PaUSA 1976
[10] B Q Li ldquoThe effect of magnetic fields on low frequency oscil-lating natural convectionrdquo International Journal of EngineeringScience vol 34 no 12 pp 1369ndash1383 1996
[11] R K Deka and V M Soundalgekar ldquoGravity modulationeffects on transient-free convection flow past an infinite verticalisothermal platerdquoDefence Science Journal vol 56 no 4 pp 477ndash483 2006
[12] S C Rajvanshi and B S Saini ldquoFree convection MHD flowpast a moving vertical porous surface with gravity modulationat constant heat fluxrdquo International Journal of Theoretical andApplied Sciences vol 2 no 1 pp 29ndash33 2010
[13] S R Jain and S C Rajvanshi ldquoInfluence of gravity modulationviscous heating and concentration on flow past a vertical
ISRN Applied Mathematics 7
plate in slip flow regime with periodic temperature variationsrdquoInternational Journal of Theoretical and Applied Science vol 3no 1 pp 16ndash22 2011
[14] K Walter ldquoNon-Newtonian effects in some elastico-viscousliquids whose behavior at small rates of shear is characterizedby a general linear equation of staterdquo The Quarterly Journal ofMechanics and Applied Mathematics vol 15 pp 63ndash76 1962
[15] K R Crammer and S Pai Magneto-Fluid Dynamics for Engi-neers and Applied Physicist McGraw- Hill New York NY USA1973
[16] C L M H Navier Memoirs de LrsquoAcademie Royale des Sciencesde Lrsquoinstitut de France vol 1 1823
[17] T R Mahapatra and A S Gupta ldquoStagnation-point flow ofa viscoelastic fluid towards a stretching surfacerdquo InternationalJournal of Non-Linear Mechanics vol 39 no 5 pp 811ndash8202004
[18] M Reza and A S Gupta ldquoMomentum and heat transfer in theflow of a viscoelastic fluid past a porous flat plate subject tosuction or blowingrdquoWorld Academy of Science Engineering andTechnology vol 23 pp 960ndash963 2008
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
ISRN Applied Mathematics 7
plate in slip flow regime with periodic temperature variationsrdquoInternational Journal of Theoretical and Applied Science vol 3no 1 pp 16ndash22 2011
[14] K Walter ldquoNon-Newtonian effects in some elastico-viscousliquids whose behavior at small rates of shear is characterizedby a general linear equation of staterdquo The Quarterly Journal ofMechanics and Applied Mathematics vol 15 pp 63ndash76 1962
[15] K R Crammer and S Pai Magneto-Fluid Dynamics for Engi-neers and Applied Physicist McGraw- Hill New York NY USA1973
[16] C L M H Navier Memoirs de LrsquoAcademie Royale des Sciencesde Lrsquoinstitut de France vol 1 1823
[17] T R Mahapatra and A S Gupta ldquoStagnation-point flow ofa viscoelastic fluid towards a stretching surfacerdquo InternationalJournal of Non-Linear Mechanics vol 39 no 5 pp 811ndash8202004
[18] M Reza and A S Gupta ldquoMomentum and heat transfer in theflow of a viscoelastic fluid past a porous flat plate subject tosuction or blowingrdquoWorld Academy of Science Engineering andTechnology vol 23 pp 960ndash963 2008
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical Problems in Engineering
Hindawi Publishing Corporationhttpwwwhindawicom
Differential EquationsInternational Journal of
Volume 2014
Applied MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Probability and StatisticsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Mathematical PhysicsAdvances in
Complex AnalysisJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
OptimizationJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CombinatoricsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Operations ResearchAdvances in
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Function Spaces
Abstract and Applied AnalysisHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of Mathematics and Mathematical Sciences
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Algebra
Discrete Dynamics in Nature and Society
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Decision SciencesAdvances in
Discrete MathematicsJournal of
Hindawi Publishing Corporationhttpwwwhindawicom
Volume 2014 Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Stochastic AnalysisInternational Journal of