me 421 assignment
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8/6/2019 ME 421 Assignment
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ME 421
ASSIGNMENT
)ep+t - : Mach an'tul EnE rteri
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r.Jl
Ilangladcsh Univcrsity of Enginccring & '['ccbnoltigyDcpartrncnt of Mcchanical llnginecring
M F-421llroblcms for Assign ntclr t
A.ict clisch:rrgirtg {).{}5 rn'/.s oJ-rvatcr hers a r,clocity ol'lJO ni/s and impingcs witlror-rtsliilck oti ti scrics of'cut'vcil vatres r,vhjch rnovc il thc srimc dircction as thc jct. 'l'lrcsirapc ol'caeh vatrc is sticlt tirat, it, w'tiulcl. if stationary. c{eflect Lire .ict thx>Lrgir i5,5".Sur{'acc t'csisti.tt"tr-:c teduccs the rclalivc vclr:city b\, 15"1, as walcr llora,s acros.s thcvancs.Irind thc lwo vclocitics ol'thc rrancs rvhich givc:r hyclraulic cfficicticy of 80'% and lbr-tltc klrvct' o,{'thesc lwo sltcccis {lnd ttrc foice oii \ianes in ancl riorrna] to [rc directiourrf' I lrcil rrnlrrcr I rr
A.jcl of weitci issLiing lionr a l6 nLnt clieuleiu tx'yzzlc sr.rilccs rvitirout silocl< a Jrxcdcill'vcd siir{'tcc which i,s.sil shai;cil thai it del'lccts 1!rr; ici'rlri'o-irgh 150", {.hc vclocit},ertcxit lrcing 90'% o{' jet vclocitl,, owing to surJacc fj'ictiolr. 'l'hc fbr.ce rxr tltc surJace is250N irr- tl-ic. clircction o{' lhe .jet wiren the cluantity clischargccl fionr ihc uozzlc is{}.006 nr3li. and hcaci art thc r,lxtzt,le t-rni.ry is 30nr. lvL,'orl,ing ?i'orl thc firsr l;r'incipicobtaiu (a) tlrc.jct velocity, (b) the co-cI{rcicnt o|vclocity from the nozzic.
A.!ct ciiscirarging 0.15 mrls cf r.vatci witli vclocity 60 m/s impinges rvitl'Lur-rr slrock ona sct'ics oJ:curveti vzu-ics which nrovcs iii lhc sernre clir.cclion a,s lhc .ici. 'l'hc shapc o{each vane is such tJrat it woulcl, if stationary, dellect the iet througb thc anglc of 160".Sirri'ace tiction t'cdrices tlrc rclativc vclocity by 8'% as waterpasses acrrfis tlrc rrancsant'l thetc is a firtlrer lvinrlagc
ioss ctprivalurt to O S(;;) rletrc ol'water. u is thc varrcveiot,iiy irirrti (a) veiocii-y oi, iirc vancs corr:cs1r
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Problem t. BAspt+rnpq;qry,,t,
0 No no
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Vu,U,- VqrJJt_Llork Cona pu ?,Lrtia ua*\b Por r-zand - e
[v, - lu-o.v+ U.uil]uz- t"7z (v,-u)u
thLrs, dfidortcg, rL:
at V,'
K\ne;vic energ?d Suqplied bt6 iat' : -T I
Mass
Force
per sec-oard
+ \,:
-) tt: 52.\mf s, 27.6rn/s
of uaAer sbrikrnZ on 1ho va'rle' fl - P I: l0OO < O-O 5: e0 k{s
aca'rng on hhe uane )n ahe d''recaor'- ol movtort'
F - m Qra,* Vnz)
- gc *f,ao t- 2v-a- a'7v (Set -22 a)7: 4362 "6 Al: g"gt
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Problom 2 A
Assumpbtorts: t) Sbmdg ProPor Pie^s2) Preeaure abn o*Pheti c'
Daba Forco eLerbod on bhe sLLrface' F:Diseha rgo, g - o- o 06 n3/ sHoad ab rloz
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/\lca,l Vt : CV \[;t
=+ 2e42-cv@=) Cv: O. g 65
V ilav Uetocib A, V, : 2 3.42 n7sCoe-f f idexb of ve(oc)D6, CV: O.ga
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Problam g,BAssurnpbi ons: t) rrl o nczzle loss
z) gbeadu uttiform prope-rPios3) Pressure abm espherie
Daba- daD vOloabA, Vt : 6C m/sDischarga, g : C"l5 rn3/svano a!Ce,,,6 -- lgc"* t6c -- 2c"
-\,,---
\ -__\ * ---.-
Jl- ---.f--- 7 // -^*__--,."1r- - r--i 2** -r -1t''):*- :- *l. Ur l-Vr, Jtr, om, Vel oc\b g briqnEte,
vr,
: \/- uVrr:g.g2'yrt: o"g z lv,-u)VuJr: Vt : 6Crn/sVur: U- VyrcosL}" : lt-- O-92 (V,- u) cps 20"
:.:- f1- O.g6(V-u)
Nork dcno b6 Udber Per ut-niA uaglv Per sac-pnd
-Vn,t-ti -VurLtt
I
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I
-lhereforQ, u&f u( u-torkdo no per unia uetVhb pe.r awndt @(v,-u) t^ o5E
B
Kinabic. e ery-lhus, eF{icrencry,
of bhe dov '=-+- #a: zIr.aaA,*q,i-oou"l,-.
-
: e z2 (#) - 4"zz (?;)'For marrP ef ficiencs4, +F = e
+ e12 Vt - 4 -22 x2LL : O-9 $: 26"45m/s
' Marea eff ictenu6, ,L= 372 (#f)^-4.zzffif:O"82 or A2Z
ouDpub pober -[' "^r|-r" -ao#l^
: zZ 563 ln: !Z"66klA
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ProbLan 4 A
Aseump2ions: l) Alo fio zz(e. /oss2) svrardg, lu.i lorm ProParDie'\3) Pr e*aw e att mo.spheri c
Daaq Velouutyof 6elt ab inleD. V -VOm/sDiameae-r of EeD. d -- OO nmAngJe., 0= (gO"- l 5O": eC"
\ \ \\.\\ ---
\u --.-
, .-+ \t\tt \//\,//\/'\-12__
Leu, t L: uQlocjv\ of bladeFrom vdoan4 vrianQ]4 'Vr
-V,- u
Vus,: V r :75rn/sVrz: A.TVrr : O'gU,*4VuJr: 1A - V r^rc,os OC
- e 1a' o-9 (v,* rt) c,os ai== t-L- O.V I (V,- u)
F$;
Norx dono par seconql : + (V^,?Lt- v''t'u): # Lv,- lu- o'78(vr- u)JJu
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: t.zB(V,-u)u+Kinobic enevgb sttP pliQd Per &ond, : + # U,'-Therefore) effic.iexcS r) - Nort< done- Per aecord(t xi"
2xt .7I (V,* u)tt::
: 3.60(,- #)+l:or, max! elfieienctdr # - O
+ o6u(+-#) :c,+ tL: 3V" 5 rn/s
Forco acuing on hhe btade Fx,: + (V^,- Vutr)T AV rz5- ov,b+o 7b(+r47elg Lro -\-'''r't) t v
s.B/ n *@.os)\zo >< c6 "15Q.&t
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Problom 5.8Assurnpbions: r) No nozzle /osS
I sueaaA uY",form ProParPia'-s3) ere*eur Q Qb mosPh ar't c
Daua:
\/vl_,_,_-1.- ---.
:ill*--!r--l*Yn.l
Lob' ou'bleb va$o uobaa6 L]-: ut:u2-F r o m , ve)o ei h6 bri orqle, V^ ,: V t
Vtrt : v,* u
Vr2: O-9Vrr ': A'g (V ,-u)Vnz: tL* UrzOosd
: tL_ O.g Vr, CosO: u-O. g (v;u) cos3o": U- o.78 (V,-u)
dev vetociV\tblade ouateb
Vt: 4 5n/sangle.,0: / 8i - tSco: 30-lut-lI vru,lI r--' l
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Problorn A.AAssuynpUiorts, /) N o noz
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lA ork dono par s>econd - m (V*,+ Vslr) tr
N\ndAAe lass : rr1 x O'45 +1t*e-lul norK dono: t-8 m (v,^u)u - o- \em
Kine,bie energbsu1Pt?ad :
*^V'DJor,- dorio PQJ secondE+ric\encry, ry a
2x l-8 m (v,-*)u- a'45 * 4nV?
3.6(v,-u)u- o-45 r*z
: rAp +lu-
o"B(v,-4il
- t.E m (v,-U)u
v,tdrl, : O
IL
#2
For rrlaxtmurn ell iiertc\, duo,6 (u-7u) - O.gtL- o=)
)V,r--_-:L/" - 2.25
65 - 2B-BA nlsz.z5
porco aovinA on bho v&nr-.,s. in bhe d\roc'bioru of moarcn'
F=1.8m(V*zr): l. ? x 35. 5l x (65- 21-8;9): )2"{3N