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FLUIDMECHANICS &MACHINERY
MODEL EXAMINATION-I
Time: 3.00hrs Ma mar!s: "00
Da#e: "$."0."$ %ART A - "0
$' $0 mar!s( De)#: MECH
A*s+er ALL ,es#i*s:
1. What is positive displacement pump and rotodynamic pump?
2. Differentiate between pump and turbines.
3. What is percentage slip in reciprocating pump?
4. Define indicator diagram .state its uses.5. What is an air
vessel in reciprocating pump?
. What are all the main types of rotary pumps?
!. "ow are centrifugal pumps classified based on casing?#. What
is the role of a volute chamber of a centrifugal pump?
$. What are the effects of cavitation?
1%. What is meant by &anometric efficiency of the
centrifugal pump?%ART / X"1'20(
A*s+er ALL ,es#i*s:
11. 'i( 'a( Describe the wor)ing and principles of reciprocating
pump. '11(
'b( What is priming in centrifugal pump? why is it necessary?
'5(Or
'ii( 'a( What is reciprocating pump? Describe the principle and
wor)ing of a double acting
reciprocating pump with neat s)etch. '13( 'b( Define *avitation.
'3(
12. 'i( + single acting reciprocating pump running at
3%rpm,delivers %.%12m3-s of water. he
diameter of the piston is 25cm and stro)e length
5%cm.determine.'i( the theoretical discharge of thepump,'ii(
coefficient of discharge and, 'iii( slip and percentage of the
slip. '1(
Or
'ii( he diameter and stro)e of a single acting reciprocating
pump are 2%%mm and 4%%mmrespectively, the pump runs at %rpm and
lifts 12litres of water per second through a height of 25m.
he delivery pipe is 2%m long and 15%mm in diameter. /ind i(
heoretical power re0uired to run
the pump ii( ercentage of slip iii( +cceleration head at the
beginning and middle of the deliverystro)e. '1(
13. 'i( he length and diameter of a suction pipe of a single
acting reciprocating pump are 5m and
1%m respectively. he pump has a plunger of diameter 15cm and a
stro)e length of 35cm.the centreof the pump is 3m above the water
surface in the pump. he atmospheric head of is 1%.3m of water
and pump is running at 35rpm.determine. 'i( ressure head due to
acceleration at the beginning of
the suction stro)e. 'ii( &aimum pressure head due to
acceleration.'iii( pressure head in thecylinder at the beginning
and at the end of the stro)e. '1(
Or
'ii( he diameter and stro)e length of a single acting
reciprocating pump are 12cm and 2%cm
respectively. he length of suction and delivery pipes is #m and
25m respectively and theirdiameters are !.5cm. if the pump is
running at 4%rpm and suction and delivery heads are 4m and
14m respectively, find the pressure head in the cylinder
'i(at the beginning of the suction and delivery stro)e.'ii( at
the middle of the suction and delivery stro)e.
'iii( at the end of the suction and delivery stro)e.
a)e atmospheric pressure head 1%.3m of water and f%.%%$ for both
pipes. '1(
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14. 'i( 'a(plain the operation of a centrifugal pump with the
help of a neat s)etch. Write short
notes on different types of casing used in centrifugal pumps.
'1%(
'b( plain the wor)ing principles of vane pump and gear pump with
neat s)etches. '(Or
'ii( + centrifugal pump having outer diameter e0ual to 2 times
the inner diameter and running at
12%%rpm wor)s against a total head of !5m. he velocity of the
flow through the impeller is
constant and e0ual to 3m-sec. the vanes are set bac) at an angle
of 3%6 at outlet. 7f the outerdiameter of the impeller is %%mm and
width at outlet is 5%mm. Determine i( 8ane angle at inlet ii(
Wor) done per sec by the impeller iii( &anometric
efficiency. '1(
15. 'i( 'a(he impeller of a centrifugal pump has an eternal
diameter of 45%mm and internal
diameter of 2%%mm and it runs at 144%rpm. +ssuming a constant
radial flow through the impeller at
2.5m-sec. and that the vanes at eit are set bac) at an angle of
256. Determine i(7nlet vane angle ii(he angle, absolute velocity of
water at eit ma)es with the tangent and iii( he wor) done per 9
of
water. '1%(
'b( plain the wor)ing of multistage centrifugal pump with neat
s)etch. '(Or
'ii( + three stage centrifugal pump has impeller 4%cm in
diameter and 2cm wide at outlet. he
vanes are curved bac) at the outlet at 45% and reduce the
circumferential area by 1%:.the
&anometric efficiency is $%: and the overall efficiency is
#%:.determine the head generated by
the pump when running at 1%%%rpm.delivers 5% litres per second.
What should be the shafthorsepower? '1(
###All the best###
