Assignment 9

1- A pump delivers gasoline (S.G.=0.68) at rate of 21,m3lhr. At pump inlet (Pr=100kPa,

7t=1m,vr=3m/s) and the pump outlet (Pz=500kPa,22=4m, vz=3m/s).

How much power is required if the pump efficiency =75Yo. Also if the leakage inside

the pump (Qr) = 3% of the pump discharge, the hydraulic losses inside the pump

=7Yo of the supply head. Calculate the volumetric, hydraulic and mechanical

efficiency of the pump.

Calculate the mechanical power loss in the pump.

2- For the centrifugal pump if Q=90m'/s. The pump turns at 1170rpm and draws

water surface is at 100kPa abs.

lf the head loss from reservoir to the pump is 1.8m, where should the pump be

placed to avoid cavitation for water at t7"C (P,.p=0.8kPa abs) and for the water at

90oC where (Pr.o=80kPa abs, S.G.=0.9635). Given NPSH =3m required for the pump

taken from PPC (pump Performance curve)

3- lf the variables in turbine design arep, D, N , Q, pgH,P). Deduce the similarity laws

for this machine. Then if for a prototype turbine (D=3m, Q=15m3/s, N=1-000rpm,

H=20m) calculate the respective data for a similar 1/5 scale model when Hr=Sm.

What are the turbine respect data when the speed is doubled?

4- The net head of a pump given by manufacturer is as follow

Q (m'ls) 0 1E-6 2E-6 3E-6 4E-6 5E-6

H (m) 1..1 1, 0.8 0.6 0.35 0.3

What is the maximum achievable flow rate if we use this pump to move water for

lower reservoir to higher reservoir. The tubing is smooth with inner diameter

=5mm and total length of 28.8mm. Take F=0.02 and neglect minor losses.

0.8

l-

_il

5- A pump deliver 15001/min of water at 20oC against a pressure rate 27OkPa, kinetic

and potential energy are negligible, if the driving motor supply gkw, what is the

overall efficiency of the pump it=f the volumetric efficiency and mechanical

efficiency are 0.95 and 0.92 receptively. What would be the hydraulic efficiency of

the pump.

Also calculate QL, hs and P1

Where Plis the power loss in mechanical friction, h1 is the hydraulic lossess in the

pump.

Ain Shams University

Faculty of Engineering

New Program

ENGR 350 Fluid Mechanics IIAssignment 9

Presented to: Prof. El-Samanoudy

Presented by: Ahmed Hassan Ibrahim

P.MANF

Assignment 9

1- A pump deliversgasoline (SG=0.68)at rate of 21m3lhr. At pump inlet (P,=100kPa,

1=1m, v1=3m/s) and the pump outlet (Pz=500kh;Zz4m, v2=3m/s).

How much power is required if the pump efficiency =75o/a Also if the leakage insdethe pump (QJ = 3%of the pump discharge, the hydraulic losses inside the pump

=7ok of t he u pply head. Cal or I at e t he vol u met ri c, hydrau I ic and medran i cal

efficiency of the pump.

Cal cul at e t he mecl"ran ical power loss in the pump,\+,' -,1\ Il\J,i...'lt

f'\ - \' I I

t-. i, L"., I*,' ,, r.. l+'{

- \r\r, v-r -- -t -.:- t 7

-\eri!--.- r ':'

-'*'*'./\) ;iyl I r'.,.:.

p x,3 iiL_ -'

[,)v!

\rlt\l :-

:t"rl

I r! ,ivr.J 1', ,.i i1 1 ,

ri i.' tt ft

; '-,;,

-l' {" ;

r ll r-c,oKr- A,

66'L rn\\

\ ./ :' ,, ,.',\ I (;. : :lr )-- ;/\ /

-)-. il/

\,i*,J11.i!

1r1

lt -.^1I t- r"i fi1

: +' ,,"jt/

\ -r'- i- .) i I

| '1",r, t

h._.\\ ,'11 \

qlvolun,r{i

.)r,:- ' .:\)

,]-Y t' lr !ri-

, rl \ ':) -lu, -\-1

-ll_- t--t-h5 h1

= C,t3 = g3'/-

t l*..t*^,.* t,.,rr^-,,. L u*hw"lri c

/n --7 *Il )tU, I"l =r t-/

,/\ttttI, h*chornl . 4(

t

{)L^n'

{^\ U,I.*-i-J \

0. \Rl\ts1

tsX o-17 )

'/,

vn€ .. !t*ic Co't3' = \

l2.rh^^,.a

r\II v^t.ho. i.<..f

lC, Srr{p fta

arJI -*.L-? a--)-). | --)

: )-"J6+ kW

Pr \D ,L (-I\ S1 ru:fi i

+- ,,L,

fu r,-, i

,2,\(

('\.

2nJ

, --].-- | I

N!-.r ti*:7-/*(

rl ,

2- br the centrifugal pump if Q=90m3/s. The pump turnsat 1170rpm and draws

water surfae is at 100k1% abs.

lf the head lossfrom reservoir to the purnp is 1.8m, where should the pump be

placed to avoid cavitation for water al 17"C (P,*=O.8kFa abs) and for the water at

90'C where (R+=8OkPa abs, SG,=0.9635). Gven NPSH =3m required for the pump

taken from PPC(pump furformance curve)

&,(

\/', ,, r r/ ,r\J\l\t' | -

r,(,

5-'l t yir'

J ' \.--, I t.* 'ffi

\iib'+.*,,.-*-- *-*_r--..._'{

(:

i

hL'1L- ,,

t"'.

-j "-rr,.". a.._)" , ,)i, :;

no.{ro ,

lf the variables in turbine design ar*,D, N , Q, pgH,p). Deduce the similarity larus

for this machine. Then if for a prototype turbine (F3m, Q=15m3/s, N=1000rpm,H=20m) calculate the respedive data for a similar 1i 5 scale model when Hr=Sm,What aretheturbine respeq datawhen thespeed isdoubled?

P= I(D,3o/V, r,s-\[\, Q\ifie^gi *ll$ ,, 't 1 r

R\-)l)rtv:a:

r(g::1 f1!*y ( /- -*.

\ ^-/

V^*i*b\ix\ unJr^*,,r*f o(

fits, *t

=C{'A lLt,*-, /V/ ^\Qt,

"\nir-) (r J

- tx

ffi\\l

sJ)

a-tl*l

AL -*L-r *q

L *-l- -'

= fl L -(J*-e

; fit'T *3("' \ /?.)u/\\an \ ; \'t

rf ?...,:fl= : 6- $= 3 {*,6rn\

I -''r ' )\ - 7\{'1"'-J t'L_.r -_y IbiL)'iL.iI):

ri "l{iTLC,{,t - cr f}r =,--,1

ll-ll\

HI

L**1-

I

(\\

\(-)\()

d/\*(,)I

t- --(J-r| *'..s

11-LoT'.\

^l I, r 2

- --51 \

ML t ))*_-_--> l.J,

= f{"L"To

tl'\ \ * (J

l,)!ri1

i--: r

\l

: "--*

i

I

I::!

'"ffiI;t, L

i-t-

( *=.r, lvi t,ttf, p) =

( ,, ,r-A0" ,.T t'1'or ( I )t' ,

.---b lX jq + lkl ; is

F *?:x c1 + lrcz +2-;r --\ V \*;? *,-!{i) ;

aI\13

u-^v l- v

L"ro--T

= ()I

=i l'i :'---I

\ valrF \\ r '*'

FJ-)I

i

Iit-

DI Pr-fol"6,f r

i)YltI I44s clL.t l

'wzr r) ;"-LXt: v

__+ _\ xLzl +

Tlz =

. rl:,-. lt

- tYl'i.-tt-+!l 1

*/_ _,'\. /J.

r \/,,' x., '-

*2 xl

]", l/r ;:r-Jel

rTr = (+il - [&#). \ll-{ * = b-\l p-r = 1s*

_\ tnF-___=__

^?tJ- X l0or

11yn^

(D\Ih

{1-!.:) .-2;;

\n.ra^l(r, 5 nn'/5

O rp^

\

I-_+_ _ I

l,J''' f ,,,oJ,

\tllr1_.

D'N',lr*,,,;n,

P\-_\D,NJ7

= ''YQ LItl.t

--r / )rj:, ,-.,\

= (3 xr uri)i ri)(2"): 2L+3, l,W: .'".{,lJr,)'l- ', ,-'j f,:r}

&

1_o

a /\ A'2z_ \t

tr t3,V

t)I1-)

<.

4X'Lc"&u *

'. I-l \-) tn-'I \U-l

i3 \\ L5/V l,'r o \''-

\z7J-lZ { t5 r

I

irt\ I\\

\r

{, rs) (rd3 k\l/

I

:*:

t\\tt1

)*/A

'r {.-}-

tc

z1

Z

r,l

\xlr,t\)

/_

/v'i{,

((.)

)K\\C\._,).

i

/ '<-> ll \ '/ --::rt-'{ \ * il*--l---?-_-\ * \\-;Jrf--z11lr / \\*-*4. Lj )V / I \

-\>t'

p,

(

_TI-L

KW

(lqr*.E X Zg+3

O ,z -,+4\-,)-'i

4- The net head of a pump given by manufacturer isasfollowQ(m"/s) l0

What is the maximum adrievable f low rate if we use this pump to move water forlower reservoir to higher reservoir. The tubing is srnooth with inner diameter

=Smm and total len$h of 28.8mffi. Take F=0.02and negled minor losses.

ll_r-l

rlltT-l .'4:-

U\tri,il

t-

* ..''\, ii"

-t rl!

'( V _t ..,' i:.Tl\ --

\ r.uri l-,.^'t Lr, _j^ 1.., ,+

x"

ritlt

{ -'r.

/ll-JI l-,,^.\/lL/

1

r\i r- ".1 i,;.

r)

i f -"Jl'n

\i'\-,-\/\.-l\

ii-'\ lI i-;.&,j i J

1i* i']l:r,.,.,.\:

{}

tcl

i*.1

ttr

l'iI

I

IiE

I ,rtI

iir \ I'tI

III

I1

I

'vI,l\TI

I

!

€

V

ei"e"r

____r__**+*l

5- Apump deliver 1500umin of water at 20'C again$ a pressLrre raleZ7)kPa, kineticand pofienliel,pno*.flg,1egligible, if the driving motor sLrpply gkw, what istheoverall'effiodncyhnd meclranical efficiency are 0.96 and 0.92 receptively, W-rat

would be the hydraulic efficiency of the pump.

Also calculate Q1_, hl and ftWhere Pl isthe power loss in meciranical fridion, hl isthe hydraulic lossess in thepump.

\

=(, )

I

il-)

NP\-1 P,,*P

z\

f *Yi--vi \ *{. 4\*-i*j - \.'*!

i -. I *;'.^. .,.._) L-_

6

r)tp

-...-l)Yw

-.---7<l.-__IJt=

$

rr i ..... I,, ' ,r t {

I,\ ?lt3 *!

: o'h-1,/\{i

Ldur*{r'., f * *.i,.,\i

\/\/\rr\-i,(-]c li u/'\

YilI

II

r/ IrlLhw,l"on,l.'.

'tt!l\

\i,Li\ ,,i t( t; a1l s; i

t t i 3:7+5f-- \)o/,\A

Lp

'<t.-.'\ i l'J'-l 3

1,.("

L

oLhSJn-,.t,. r -z\ r^J. (:\')

li -i,.. ;

Il I,r- l"u.t"\ ,r h,\1 -zh:

1

n---/1.3

t\ :.- rn

n{r,,- r'-n'..ha^\c <i-/

c) , a.: "i-

f)f-,f :il

I * --1i.i..

.t. lttt1"-A^\.n --lt) "r ,. ,\/, t^ i ltr I- NVV

f)Y&i.r

::\

-'t. \

- hg

/ ...I

r,

11"

2ao K r,o\3.rr Y r 63

2--1. Snrr

= __X_Qlj

,'*1.: