cfd simulations and validation through test data …in double -pipe counter-flow heat exchangers o f...

http://www.iaeme.com/IJMET/index.asp 818 [email protected]

International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 5, May 2017, pp. 818–831, Article ID: IJMET_08_05_089 Available online at http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=5 ISSN Print: 0976-6340 and ISSN Online: 0976-6359 © IAEME Publication Scopus Indexed

CFD SIMULATIONS AND VALIDATION THROUGH TEST DATA OF A DOUBLE PIPE

COUNTER FLOW HEAT EXCHANGER Peddi Dilleswara Rao

M. Tech, Department of Mechanical Engineering, K L University, Guntur, Andhra Pradesh, India

B. Nageswara Rao Professor, Department of Mechanical Engineering,

K L University, Guntur, Andhra Pradesh, India

ABSTRACT A comparative study is made considering the test data of a double-tube counter-

flow heat exchanger to examine the adequacy of the turbulent models in computational fluid dynamics (CFD) codes. Models of the double-pipe heat exchangers (straight-tube as well as U-tube lab models of heat exchangers) are generated using SOLIDWORKS and carried out the flow analysis using ANSYS (FLUENT). In order to examine the validity of the developed models and results of the flow simulations, the outlet temperatures of the cold and hot fluids in the heat exchanger have been obtained and selected the appropriate turbulent model which yielded results close to the measured temperatures of the outlet hot and cold fluids. Velocity, pressure and temperature distributions are presented for the specified inlet conditions. The Nusselt number is evaluated considering the dimensions and material properties of tubes, properties of hot and cold fluids, inlet temperatures and mass-flow rates. The estimates of outlet temperatures are matching well with measured ones. This study confirms the validation of numerical simulations and generated models useful in the design as well as in the performance evaluation of double-tube counter-flow heat exchangers. Keywords: ANSYS, CFD, Cold fluid, Double-pipe heat exchanger, Flow simulation, inlet temperatures, hot fluid, outlet temperatures, Solid works. Cite this Article: Peddi Dilleswara Rao and B. Nageswara Rao. CFD Simulations and Validation Through Test Data of a Double Pipe Counter Flow Heat Exchanger. International Journal of Mechanical Engineering and Technology, 8(5), 2017, pp. 818–831. http://www.iaeme.com/IJMET/issues.asp?JType=IJMET&VType=8&IType=5

Peddi Dilleswara Rao and B. Nageswara Rao


1. INTRODUCTION Several types of equipment namely, heat exchangers perform heat transfer from higher to lower temperature obeying the second law of thermodynamics in all chemical reactions and unit operations. Heat exchanger is a device utilized to exchange the heat between two fluids of different temperatures without mixing by radiation, conduction and convection. Radiation plays insignificant role and convection plays a major role in heat exchangers. Conduction takes place when the heat from the fluid temperature passes through the thin conductive solid wall. Heat exchangers are being used extensively in the chemical processing plants, steam power plants, heating and air conditioning in buildings, household refrigerators, car radiators, radiators for space vehicles and so on [1-3].They are classified according to transfer process, construction, flow arrangement (viz., parallel flow, counter flow, single-pass cross flow and multi-pass cross flow.), surface compactness, number of fluids and heat transfer mechanisms [4]. The design of heat exchangers involves cost, performance assessment (long-term), inevitable investigation of heat transfer, pressure drop and the effectiveness [5].

Figure 1 Schematic of a double-pipe counter-flow heat exchanger

Shell- and tube- type heat exchangers are being used extensively in the process industries, whereas plate, spiral and brazed finned- type heat exchangers are used for specific applications. In double-pipe counter-flow heat exchangers of concentric tube construction, hot and cold fluids flow in an opposite direction (see Figure-1). Since the diameter of the pipes is small, they can be used in high pressure applications and also useful where a wide range of temperature is needed. The hot fluid flowing in the inner pipe of the double-pipe heat exchanger transfers the heat to the flowing cold water in the outer pipe. The system will be in a relative steady state for the controlled flow rate or inlet temperatures. Due to simplicity and a wide range of usages in chemical, food, oil and gas industries, it is formed the subject by a large number of publications relevant to the characteristics of working fluids [6-8]; heat transfer enhancement methods, viz., active methods [9, 10], passive methods [11-14], a combination of both active and passive methods namely, compound method [15, 16], geometry change [17], and using nano fluids [18-20]. Double-pipe heat exchangers have also been used in solar and geothermal applications [21, 22].In active method, an external force (for example, electromagnetic field) is applied for enhancing the heat transfer rate, whereas geometrical modifications and various inserts play a central role in the passive methods.

FLUENT, CFX, STAR CD, FIDAP, ADINA, CFD2000 and PHOENICS are frequently used commercial computational fluid dynamics (CFD) codes in the design and analysis of heat exchangers [23], which generally require large amounts of computer power, computer memory and computational time [24, 25]. In order to become an integral part of all design processes, the CFD developmental activities are progressing rapidly. Due to lack of

CFD Simulations and Validation Through Test Data of a Double Pipe Counter Flow Heat Exchanger


universally applicable turbulent models, there is a need to examine the adequacy of CFD simulations with test data [26]. Hence, validation through testing is unavoidable for any design and numerical simulations of heat exchangers [27-36].

Figure 2 Experimental setup of a double-pipe counter-flow heat exchanger

(a) Straight-tube construction; (b) U-tube construction

In order to examine the adequacy of the turbulent models in computational fluid dynamics (CFD) codes, a comparative study is made in this paper considering the test data of a double-tube counter-flow heat exchanger. Figure-2 shows experimental setup of a double-pipe heat exchanger having straight tube construction and U-tube construction. Using SOLIDWORKS straight-tube as well as U-tube lab models of double-pipe heat exchangers are generated. ANSYS (FLUENT) is utilized for carrying out the flow analysis for the specified inlet and outlet conditions. The outlet temperatures of the cold and hot fluids in the heat exchanger have been obtained and compared with the measured temperatures of the outlet hot and cold fluids to trace the appropriate turbulent model which yielded results close to the measured ones. Contour plots of velocity, pressure and temperature are presented for the specified inlet conditions. The Nusselt number is evaluated considering the dimensions and material properties of tubes, properties of hot and cold fluids, inlet temperatures and mass-flow rates. The estimates of outlet temperatures are matching well with measured ones. Validation of numerical simulations and generated models through comparison of test data in the present study will be useful in the design as well as in the performance evaluation of double-tube counter-flow heat exchangers.

2. ANALYSIS To design or assess the performance of a double-tube counter-flow heat exchanger, the total heat transfer rate has to be related to the inlet and outlet fluid temperatures, the overall heat transfer coefficient, and the heat transfer surface area.

The rate of heat transfer Q is given by [3, 37]

ln)()( TUATTCmTTCmQ mtcicopcchohiphh (1)

The logarithmic mean temperature difference (LMTD) between the hot and cold fluids,

1ln )ln()ln()( LOLO TTTTT (2)

The effectiveness is defined as 1

max QQ (3)

The maximum possible heat transfer rate,



cihip TTCmQ minmax

(4) Here, cm and hm are the mass flow rates of cold and hot fluids respectively; pcC and phC

are the specific heats of cold and hot fluids respectively; minpCm is the smaller of phhCm and

pccCm for the hot and cold fluids; hiT and ciT are the inlet temperatures of hot and cold fluids respectively; hoT and coT are the outlet temperatures of hot and cold fluids respectively;

cohi TTT 0 and cihoL TTT ; Um is the overall heat transfer coefficient;)( oit dDLA , is the total heat transfer area; id and od are the inner and outer diameters of

the inner tube respectively; iD is the inner diameter of the outer tube; 122 )( ooie ddDD , is

the equivalent diameter; oih dDD , is the hydraulic diameter; 124 ihhmh dmu and

1224 oiccmc dDmu are the average velocity of the hot and cold fluids respectively.

Computational fluid dynamics (CFD) deals with numerical solution of partial differential equations governing the transport of mass, momentum, and energy in moving fluids. The law of conservation of mass yields the continuity equation. Momentum equations are arrived for velocity ( ju ) in directions )3,2,1( jx j following the Newton’s second law of motion and the Stoke’s stress laws. Energy equation for the transport temperature (T ) or enthalpy ( h) is derived utilizing the first law of thermodynamics with Fourier’s law of heat conduction

i

condi xTq , . The continuity, momentum and energy equations in moving fluids are [38,

39]

0

j

j

xu

t

(5)

iui

j

ieff

jij

iji SBxu

xxp

xuu

tu

(6)

Q

xT

xxhu

th

jeff

jj

j

, (7) Here, p is the pressure; refp TTCh , is the enthalpy; iB is the body force in directions

)3,2,1( ixi ; iuS stands for the viscous terms that are in addition to those expressed by

j

ieff

j xu

x ;Q is the volumetric rate of heat generation; eff is the effective viscosity; and

eff is the effective thermal conductivity. In laminar flows eff and eff are the fluid properties, whereas in turbulent flows they are turn out to be properties of the flow rather than those of the fluid [40]. Turbulent flows are commonly encountered in practical applications. Assuming rapid and random fluctuations about the mean value, the equations of unsteady laminar flow are converted to the time-averaged equations. The additional terms arising from this operation are the so-called Reynold’s stresses, turbulent heat flux, etc. To express these fluxes in terms of the mean properties of the flow is the task of a turbulent model. From a computational view point, a turbulent flow is equivalent to a laminar flow with complicated effective viscosity. The popular Launder and Spalding “two-equation models” of turbulence



[40] employ, as one of the equations, the equation for the kinetic energy ( k ) of the fluctuating motion, which reads

G

xk

xxuk

tk

jk

ji

i

(8) Here k is the diffusion coefficient for k , G is the rate of generation of turbulence energy,

and is the kinematic rate of dissipation. The quantity )( G is the net source term in the equation. A similar differential equation governs the variable .Model of the heat exchanger can be done using SOLIDWORKS whereas flow analysis can be carried out using ANSYS (FLUENT), which consists of turbulent models namely, k standard model, RNGk model, k standard model, etc [41]. Due to lack of universally applicable turbulent models there is a need for comparison of CFD simulations with test data and design validation through testing is unavoidable.

3. NUMERICAL SIMULATIONS Potrascioiu and Radulescu [42] have conducted tests on double-pipe heat exchangers for the specified inlet temperatures and measured the outlet temperatures of the cold and hot fluids. Their numerical simulations are comparable with test data. Their mathematical model contains an equation of the heat balance associated to hot and cold fluids, mass-flow rates, inlet and unknown outlet temperatures. They also equated the rate of heat transfer Q with the product of the overall heat transfer coefficient mU , total heat transfer area tA and the logarithmic mean temperature difference lnT . They have obtained two non-linear equations and solved them through an iterative process for the outlet temperatures of the cold and hot fluids. They have conducted two types of tests. In case-I, length of the heat exchanger ( L ) is 750mm having 1mm thick inner and outer tubes, whose inner diameters are 10mm and 20mm respectively. Mass flow rate of hot fluid hm varies from 0.0380 to 0.0405kg/sec, whereas that of cold fluid cm varies from 0.0333 to 0.0527kg/secat 10.6 0Cinlet temperature of cold fluid and varying inlet temperature of the hot fluid from 70.2 to 72.7 0C. Table-1 gives thermal properties of the fluid (water) to be specified while carrying out analysis using ANSYS (FLUENT). In case-II, length of the heat exchanger ( L ) is 935mm having 1mm thick inner and outer tubes, whose inner diameters are 12mm and 26mm respectively. Mass flow rate of hot fluid hm varies from 0.0527 to 0.0680kg/sec, whereas that of cold fluid cmvaries from 0.0255 to 0.0611kg/secat55.30Cinlet temperature of the hot fluid and varying inlet temperature of the cold fluid from 10.7 to11.80C.In numerical simulations, thermal properties of water specified for case-II are given in Table-2.



Table 1 Thermal properties of water specified in the numerical simulations of a double-pipe heat exchanger for case-I conditions.

Temperature (°C)

ρ(kg/ ) (J/kg. K)

μ (cP)

(W/m.K)

Pr

10.6 999.40 4088.7 12.458 0.5890 8.6415 70.4 977.12 4066.9 3.917 0.6630 2.4027 70.2 977.20 4066.9 3.928 0.6620 2.4097 70.2 977.20 4067.0 3.928 0.6628 2.4097 70.5 977.66 4067.0 3.911 0.6631 2.3992 71.1 976.71 4067.0 3.880 0.6635 2.3783 71.0 976.77 4067.0 3.885 0.6634 2.3817 71.4 976.53 4067.1 3.864 0.6639 2.3676 71.2 976.65 4067.1 3.875 0.6639 2.3748 72.0 976.18 4067.2 3.873 0.6642 2.3475 72.7 975.76 4067.4 3.798 0.6648 2.3241

[http://www.mhtl.uwaterloo.ca/old/onlinetools/airprop/airprop.html]

Table 2 Thermal properties of water specified in the numerical simulations of a double-pipe heat exchanger for case-II conditions.

Temperature (°C)

ρ(kg/ ) (J/kg. K)

μ (cP)

(W/m.K)

Pr

55.3 985.21 4065.8 4.8799 0.6495 3.055 10.7 999.47 4088.5 12.42 0.5890 8.615 10.9 999.44 4088.1 12.35 0.5899 8.562 11.0 999.43 4087.9 12.32 0.5801 8.532 11.5 999.35 4087.1 12.15 0.5909 8.402 11.6 999.34 4086.9 12.12 0.5911 8.382 11.7 999.32 4086.8 12.09 0.5912 8.356 11.7 999.32 4086.8 12.09 0.5912 8.356 11.8 999.31 4086.6 12.05 0.5914 8.331 11.8 999.31 4086.6 12.05 0.5914 8.331

[http://www.mhtl.uwaterloo.ca/old/onlinetools/airprop/airprop.html] Figure-3 shows the double-pipe heat exchanger (straight tube) model generated using

SOLIDWORKS. Velocity and temperature distributions in the counter flow simulations using the k turbulent model of SOLIDWORKS for the inlet conditions ( hiT =70.2°C, =10.6°C,

mhu =140lt/hr, mcu =130lt/hr) are shown in Figures 4 and 5 respectively. Another U-tube model for double-pipe heat exchanger (see Figure-6) is analysed for the inlet conditions ( hiT=50°C, =27°C, mhu =300lt/hr, mcu =140lt/hr). Figure-7 shows the velocity and temperature distributions. Analysis results of k-ε model of SOLIDWORKS are found to be reasonably in good agreement with the measured results at the outlets of the double-pipe heat exchanger.



Figure 3 Straight tube model generated using SOLIDWORKS

Figure 4 Velocity distribution in straight tube model simulated using the k turbulent model of SOLIDWORKS

Figure 5 Temperature distribution in straight tube model simulated using the k turbulent model of SOLIDWORKS.

Figure 6 Straight tube model generated using SOLIDWORKS



Figure 7 Velocity and temperature distribution in U- tube model simulated using the k turbulent model of SOLIDWORKS.

Meshing of the three-dimensional model done by ANSYS FLUENT 15.0 software package is shown in Figure-8. Steel pipe properties specified are: Density, ρ = 8030kg/m3; Specific heat, = 502.48J/kg. K; Thermal conductivity, = 16.27W/m. K. Velocity is specified for the mass flow rates at the inlet of the inner tube and annulus tube of the double-pipe heat exchanger. Pressure is used for the outlet of inner tube and annulus tube. No-slip condition is applied at tube walls. Thermal properties of cold and hot water in Tables 1 and 2 are considered. Inlet and outlet conditions of the annulus tube are specified in reverse to the direction of inner tube for the counter-flow arrangement.

Cut-cell approach is adopted while meshing. Rectangular cells are used for mesh process in tube wall and fluid domain. The 3D model consists of 238810 elements with 280983 nodes. ANSYS FLUENT 15.0 follows finite volume formulation for the governing equations of the flow. Equations of momentum, turbulent dissipation rate and temperature terms are modelled by the second-order upwind scheme. Solution method for pressure velocity coupling scheme adopts SIMPLE algorithm. Convergence of the solution is limited by setting the relative residual as 610 for all variables.

Figure 8 Meshing of the three-dimensional model of a double-pipe heat exchanger done by ANSYS FLUENT 15.0



A comparative study is made on turbulent models (namely, k standard model, RNGk model, k standard model)to examine the variation of hot and cold fluid

temperature along the length of the heat exchanger. It can be seen from Figures 9 and 10 that k standard model yields the results close to the test results.Figure-11showscomparison

turbulent models in variation of Nusselt number along the length of the inner pipe heat exchanger. Since, k standard model represents the actual flow behaviour, Nusselt number corresponding to this model is more appropriate. Velocity and pressure contour plots along the length of the heat exchanger are shown in Figure-12.

Table-3 presents a comparison on outlet temperature of hot and cold fluids estimated from familiar turbulent models of ANSYS (FLUENT) for the inlet temperature of cold fluid, =10.60C. It is noted that the results obtained using k standard model are reasonably in good agreement with test results. Comparative study is made on the estimation of outlet temperature of hot and cold fluids from k standard model of ANSYS (FLUENT) for the inlet temperature of hot fluid, =55.30C in Table-4. The estimates of outlet temperature of hot and cold fluids are found to be reasonably in good agreement with test results.

Modelling of the heat exchanger can be done using SOLIDWORKS whereas flow analysis can be carried out using ANSYS (FLUENT). Analysis results using k standard turbulent model of ANSYS (FLUENT) in the present study are close to the test data.

Figure 9 Comparison turbulent models invariation of hot fluid temperature along the length of the inner pipe heat exchanger.

Figure 10 Comparison turbulent models invariation of cold fluid temperature along the length of outer pipe heat exchanger.



Figure 11 Comparison turbulent models invariation of Nusselt number along the length of the inner pipe heat exchanger.

Figure 12 Velocity and pressure contour plots along the length of the heat exchanger

Table 3 Comparison on outlet temperature of hot and cold fluids estimated from familiar turbulent models of ANSYS (FLUENT) for the inlet temperature of cold fluid, =10.60C

Temperature (0C) Test [42]

Inlet velocity (m/s)

Turbulent models of ANSYS (FLUENT) k standard k RNG k standard

70.2 61.2 23.0 0.5287 0.1660 55.81 25.64 52.34 23.42 60.4 22.71 70.2 61.2 22.4 0.5214 0.1798 55.91 25.85 52.45 23.95 60.6 22.87 70.4 61.4 24.2 0.5286 0.1936 54.69 26.65 53.16 22.22 59.55 24.63 70.5 60.8 22.0 0.5142 0.2075 54.17 24.16 52.94 23.18 58.42 24.83 71.0 61.2 21.4 0.5072 0.2213 55.59 23.71 53.21 23.51 58.46 21.31 71.1 61.2 21.4 0.5144 0.2213 55.56 23.33 54.56 20.33 58.71 21.52 71.2 61.2 20.9 0.5036 0.2351 56.04 23.92 54.27 22.12 59.35 20.47 71.4 61.3 20.9 0.5108 0.2351 57.06 23.75 55.02 21.93 59.41 20.62 72.0 61.7 20.4 0.4966 0.2490 56.83 23.77 55.59 21.26 59.57 20.72 72.7 62.3 20.0 0.4968 0.2628 57.57 22.02 55.99 21.36 59.89 21.15



Table 4 Comparison on outlet temperature of hot and cold fluids estimated from k standard model of ANSYS (FLUENT) for the inlet temperature of hot fluid, =55.30C

Temperature (0C) Test [42]

Inlet velocity (m/s) Turbulent model k standard

10.7 47.5 17.7 0.6113 0.1290 49.16 20.94 10.9 48.2 18.6 0.5988 0.1622 49.05 20.41 11.0 48.5 19.7 0.5738 0.1357 49.21 21.10 11.5 49.2 22.0 0.5489 0.0951 49.71 23.84 11.6 49.4 23.3 0.4740 0.0737 49.87 24.25 11.7 49.9 25.4 0.5738 0.0678 49.91 26.41 11.7 49.6 25.2 0.5364 0.0678 49.49 26.24 11.8 49.5 25.1 0.5239 0.0678 50.73 26.05 11.8 49.2 24.5 0.4740 0.0678 50.97 26.63

4. CONCLUSION This paper examines the adequacy of the turbulent models in computational fluid dynamics (CFD) codes through comparison of test data of a double-tube counter-flow heat exchanger. Using SOLIDWORKS straight-tube as well as U-tube lab models of heat exchangers are generated and carried out the flow analysis using ANSYS (FLUENT). The outlet temperatures of the cold and hot fluids in the heat exchanger have been obtained and selected the appropriate turbulent model which yielded results close to test data. Velocity, pressure and temperature distributions are presented for the specified inlet conditions. The Nusselt number is evaluated considering the dimensions and material properties of tubes, properties of hot and cold fluids, inlet temperatures and mass-flow rates. The estimates of outlet temperatures are matching well with measured ones using k standard turbulent model of ANSYS (FLUENT). There is no universal turbulent model existing. The designer has to select a suitable model through comparison with test data. This study confirms the validation of numerical simulations and generated models useful in the design as well as in the performance evaluation of double-tube counter-flow heat exchangers.

REFERENCES [1] A.P. Fraas, “Heat Exchanger Design”, Wiley India Private Limited, New Delhi, India

(2011).

[2] S.B. Thakore and B.I. Bhatt, “Introduction to Process Engineering and Design”, McGraw-Hill Education (India) Private Limited, New Delhi, India (2015).

[3] O.Y. Dutta, T.Therisa and B. Nageswara Rao, “Design validation through testing of a double-tube counter-flow heat exchanger”, International Journal of Control Theory and Applications, Vol.10, No.1, pp.399-409 (2017).

[4] R. K. Shah, "Heat Exchangers", in Encyclopedia of Energy Technology and the Environment, edited by A. Bisio and S. G. Boots, pp. 1651-1670, John Wiley & Sons, New York, 1994.

[5] M. Omide, M. Farhadi and M. Jafari, “A Comprehensive review on double pipe heat exchangers”, Applied Thermal Engineering, Vol.110, pp.1075-1090 (2017).

[6] M. Sheikholeslami, M. Gorji-Bandpy and D. Ganji, “Fluid flow and heat transfer in an air-to-water double-pipe heat exchanger”, The European Physical Journal Plus, Vol.130, pp 1–12 (2015)



[7] M. Sheikholeslami, M. Jafaryar, F. Farkhadnia, M. Gorji-Bandpy and D.D. Ganji, “Investigation of turbulent flow and heat transfer in an air to water double pipe heat exchanger”, Neural Computing and Applications, Vol. 26, pp.941–947 (2015)

[8] Ting Ma, Wen-xiao Chu, Xiang-yang Xu, Yi-tung Chen and Qiu-wang Wang, “An experimental study on heat transfer between supercritical carbon dioxide and water near the pseudo-critical temperature in a double pipe heat exchanger”, International Journal of Heat and Mass Transfer, Vol.93, pp.379–387 (2016)

[9] W. El-Maghlany, E. Eid, M. Teamah, and I. Shahrour, “Experimental study for double pipe heat exchanger with rotating inner pipe”, International Journal of Advanced Scientific and Technical Research, Vol.4, No.2, pp.507–524 (2012).

[10] Z. Zhang, Y. Ding, C. Guan, H. Yan and W. Yang, “Heat transfer enhancement in double-pipe heat exchanger by means of rotor-assembled strands”, Chemical Engineering Process, Vol. 60, pp. 26-33 (2012)

[11] R.L. Mohanty, S. Bashyam and D. Das, “Numerical analysis of double pipe heat exchanger using heat transfer augmentation techniques”, International Journal of Plastics Technology, Vol.18, pp.337–348 (2014)

[12] M. Taghilou, B. Ghadimi, M. Seyyedvalilu, Optimization of double pipe fin-pin heat exchanger using entropy generation minimization, International Journal of Engineering Transactions C: Aspects, Vol. 27, No.9, pp. 1431–1438 (2014).

[13] Huai-Zhi, Han, Bing-Xi Li, Hao Wu, Wei Shao, “Multi-objective shape optimization of double pipe heat exchanger with inner corrugated tube using RSM method”, International Journal of Thermal Sciences, Vol. 90, pp. 173–186 (2015).

[14] Z. Iqbal, K. Syed, M. Ishaq, “Fin design for conjugate heat transfer optimization in double pipe”, International Journal of Thermal Sciences, Vol.94, pp.242–258 (2015)

[15] W. Duangthongsuk, S. Wongwises, “An experimental investigation of the heat transfer and pressure drop characteristics of a circular tube fitted with rotating turbine-type swirl generators, Experimental Thermal and Fluid Science”, Vol.45, pp. 8– 15 (2013).

[16] M. Shewale Omkar, A. Mane Pravin, A.H. GazgeSajid, A. Pasanna Pradeep, “Experimental investigation of double-pipe heat exchanger with helical fins on the inner rotating tube”, International Journal of Research in Engineering and Technology, Vol.3, No.7, pp.98–102 (2014).

[17] R. Yang and F.P. Chiang, “An experimental heat transfer study for periodically varying-curvature curved-pipe”, International Journal of Heat and Mass Transfer, Vol.45, pp. 3199–3204 (2002)

[18] M. Sarafraz, and F. Hormozi, “Intensification of forced convection heat transfer using biological nanofluid in a double-pipe heat exchanger”, Experimental Thermal and Fluid Science, Vol. 66, pp. 279–289 (2015)

[19] P.D. Prasad, A. Gupta and K. Deepak, “Investigation of trapezoidal-cut twisted tape insert in a double pipe U-tube heat exchanger using Al2O3-water nanofluid”, Procedia Material Science, Vol.10, pp.50–63 (2015).

[20] A. Shakiba and K. Vahedi, “Numerical analysis of magnetic field effects on hydrothermal behavior of a magnetic nanofluid in a double pipe heat exchanger”, Journal of Magnetism and Magnetic Materials, Vol. 402, pp. 131–142 (2016).

[21] J.D. Tempelton, F. Hassani and S.A. Ghoreishi-Madiseh, “Study of effective solar energy storage using a double pipe geothermal heat exchanger”, Renewable Energy, Vol. 86, pp. 173–181 (2016)



[22] G. Galoppi, D. Biliotti, G. Ferrara, E. Carnevale and L. Ferrari, “Feasibility study of a geothermal power plant with a double-pipe heat exchanger”, Energy Procedia, Vol. 81, pp. 193–204 (2015)

[23] E. Ozden, I. Tari, “Shell side CFD analysis of a small shell-and-tube heat exchanger”, Energy Conversion & Management, Vol.51, pp.1004-1014 (2010).

[24] B. Sunden, “Computational heat transfer in heat exchangers”, Heat Transfer Engineering, Vol.28, pp. 895–897 (2007)

[25] B. Sunden, “Computational fluid dynamics in research and design of heat exchangers”, Heat Transfer Engineering, Vol.28, pp. 898–910 (2007)

[26] M. M. Aslam Bhutta, N. Hayat, M. H. Bashir, A. R. Khan, K. N. Ahmad and S. Khan, “CFD applications in various heat exchangers design: A review”, Applied Thermal Engineering, Vol.32, pp. 1-12 (2012).

[27] R.K. Shah and D.P. Sekulic, “Fundamentals of Heat Exchanger Design”, John Wiley & Sons, Inc., New Jersey (2003).

[28] Milind V. R., Madhukar S. T., “Water-to water heat transfer in tube–tube heat exchanger: Experimental and analytical study”, Applied Thermal Engineering,Vol.25,pp. 2715-2729 (2005).

[29] K.P. Mohajeri, I. Mirzaie, N. Pourmah mound, M. Rahimi and S.Majidyfar, “Numerical study of single-phase forced convective heat transfer with flow friction in round tube heat exchangers”, World Academy of Science, Engineering and Technology, Vol.70, No.47, pp.345-351 (2010).

[30] C. Patrascioiu and D. Mihaescu, “The steady state modelling and simulation of the chemical multivariable systems - Case studies”, Proceedings of 20th European Symposium on Computer Aided Process Engineering, Ischia, Italy, Computer Aided Chemical Engineering,Vol.28, pp.1657-1662 (2010).

[31] H. Zheng, J. Bai, J. Wei and L. Huang, “Numerical simulation about heat transfer coefficient for the double-pipe heat exchangers”, Applied Mechanics and Materials, Vol. 71-78, pp.2477-2580 (2011).

[32] H. Kahalerras and N. Targui, “Analysis of fluid flow and heat transfer in a double pipe heat exchanger with porous structures”, Energy Conversion and Management, Vol.49, No.11, pp.3217-3229 (2008).

[33] S. Eiamsa-ard, S. Pethkool, C. Thianpong and P.Promvonge, “Turbulent flow heat transfer and pressure loss in a double pipe heat exchanger with louvered strip inserts”, International Communications in Heat and Mass Transfer, Vol.35, pp.120–129 (2008)

[34] N. Sahiti, F. Durst and F. Dewan, “Heat transfer enhancement by pin elements”, International Journal of Heat and Mass Transfer, Vol.48, pp.4738–4747 (2005).

[35] Yonghua You, Aiwu Fan, Wei Liu and Suyi Huang, “Thermo-hydraulic characteristics of laminar flow in an enhanced tube with conical strip inserts”, International Journal of Thermal Sciences,Vol.61, pp.28-37 (2012)

[36] Patrascioiu C, Radulescu S “Modelling and simulation of the double tube heat exchanger-Case studies”, In: Advances in Fluid Mechanics, Heat & Mass Transfer,pp.35– 41 (2012)

[37] M. Necati Ozisik, “Basic Heat Transfer”, McGraw-Hill, Inc. (1997).

[38] S.V. Patankar, “Numerical Heat Transfer and Fluid Flow”, Series in Computational Methods in Mechanics and Thermal Sciences, Hemisphere Publishing Corporation, Printed and bound in India by Replika Press Private Limited (2016).

[39] Anil Waman Date, “Introduction to Computational Fluid Dynamics”, Cambridge University Press, New York (2005)



[40] B.E. Launder and D.B. Spalding, “Mathematical Models of Turbulence”, Academic Press, New York (1972)

[41] ANSYS Inc, “Theory guide”, section-4.4.1.1-4.4.1.2, (August 2015).

[42] C. Patrascioiu and S. Radulescu, Modeling and simulation of the double tube heat exchanger case studies. In: Advances in Fluid Mechanics, Heat and Mass Transfer, pp 35–41 (2012).

[43] Shyam Narayan Shukla, Ruchi Khare and Vishnu Prasad, Performance Evaluation of Turbulence Models for Flow Simulation of Double Suction Centrifugal Pump. International Journal of Civil Engineering and Technology, 7(6), 2016, pp.01–10.

[44] Abhay Sehgal, Vinay Aggarwal and Satbir S. Sehgal, Computational Analysis of Stepped and Straight Microchannel Heat Sink. International Journal of Mechanical Engineering and Technology, 8(2), 2017, pp. 256–262.

cfd simulations and validation through test data …in double -pipe counter-flow heat exchangers o f...

Documents