fm qpaper nit raipur mech 5th sem

8/8/2019 FM Qpaper Nit Raipur Mech 5th Sem

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NATIONAL INSTITUTE OF TECHNOLOGYRAIPUR

CSVTU SCHEME

Semecter: B.E. V Sem. Branch: Mechanical Engg.$ublect: Fluid Machinery

UNIT - I

Boundary Layer TheolyBoundary layer definition and characteristics, momentum equation, Laminar and turbulent boundary Layer, Totaldrag, separation and control.

Flow arcund submerge bodies

Force exerted by flowing fluid on a body: Drag and lift, stream lined and bluff body, Drag on sphere and cylinder,circulation and lift on circular cylinder, lift of an air foil.

UNIT - II

lmpact of Free Jets

lmpulse momentum principle, force exerted by the jet on stationary flat and curved plate, hinged plate, moving plateand moving curve vanes, jet propulsion of ship.

,

lmpulse Turbine

Classification of turbine, impulse turbine, Pelton wheel, Construction working, work done, head efficiency andDesign aspects, Goveming of impulse turbine.

uNtT - illReaction Turbine

Radial flow reaction turbine, Francis turbine: construction, working, workdone, efficiency, design aspect, advantages& disadvantages over pelton wheel.

Axial flow reaction turbine

Propeller and Kaplan turbine, bulb or tubular turbine, draft tube, specific speed, unit quantities, cavitation, degree ofreaction, performance characteristias, surge tanks, governing of reaction turbine.

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Gentrifugal Pumps

Classiflcation of Pumps, Centrifugal pump, Construction, working, workdone, heads, efficiencies, multistagecentrifugal pump, pump in series and parallel, specific speed, characteristic, net positive suction head, cavitation.

UNIT-V

Reciprocating Pumps

Classiflcation, component and working, single acting and double acting, discharge, workdone and power required,coefficient of discharge, indicator diagram, air vessels.

Fluid system

Hydraulic accumulator, Hydraulic intensifier, Hydraulic Press, hydraulic crane, hydraulic lift, hydraulic Ram,hydraulic coupling, hydraulic torque converter, air lift pump, jet pump.


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Code M88514S VT I)

Time: Three hours

S.Ja *h,{Fifth Sem) Examination Nov-Dec 0{}Subject: Fluid Machinery ir

Mechanical EngineeringMax, Marks B0Min. Marks 2B

Note: Affera pt arry two parts from wch question excEt from quertUnile and 4 from rnhich

attenryt any vne part, Assunte any suitable data if required. {I a. Find the following UounOury layer param"t"ru fo, the veloqlty distribution prescribed,i

Iav*=[{tlu: (i) displacement thickness and momentumthiol$ness (ii) energy thickness," Uo \.d/1-

\ v --'--or

AIso calculate ttre energl,loss due to boundary layer if at a partipular section the boundarylayer thickness is 3,0 cm and the free sheam velooity 12 m/s, il 08

1 b. A kite having dimensions 0.9 x 0.9 m and weighing 7.5 N is mailitained in air at an angle of10o to the horizontal. The string attached to the kite is inclined to [he horizo ntal at 45o and atthis position, the drag and lift coefficients are estimated to be 0.6 [na O.a respectively. Makecalculations fol the wind speed and tension in the string. Take pu; 4 t.t tgl*t 08

1 c. Find the expression for lift on cylinder, I

2 a, Astationary vane having an inlet angle of zero degree and an Jutlet angle of 25o ,..rrrl"t,water at velocity of 50 m/s. Determine the components of force actingflon it in the direction of thejet velocity and normal to it. Also find the resultant force in magnitrlae and direction per kg of

il

flow IIf the vane stated above is moving with a velocity of 20 m/s in the Jhreotion ofthe jet calculatethe force components in the direction of vane velocity and across it,f also the resultant force inmagnitude and direction. Calculate the work done and power developef per kg of flow. 16

oRl2 b. The following are the design parameters of a large Pelton turbine:

I

Head at diskibutor = 630 m; discharge = 12.5 nr'/s; power 65 M\b; speed of rotation = 500li

r.p,m; runner diameter = L96 m; number ofjets = 4;jet diameter = 19{ mm; angle tluough which

rn{ of theturbine

= 96%o.

Determine the hydrbulic powbr.losses in the distribritor noiz.le assemblf and the buckets.' ' l63 a. (i) Define the terms unit speed, unit power and specific speed as

"ipd* connection

with operation of hydraulic turbine, fl OO(ii) Explain the lerm degree of reaction as applied tolhydraulic turdine. Is it possible to have a

turbine with 100 o/o degreeof reaction? If not why? i 04

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3 i). A reaction turbine dorks at 450 r.p.m. under a head of 120 nr,. Its diameter at iniet is 1.2 nr

and the flow area is p.+ m'. fhe angles made by absolute and relative velocities at illlet are?.0o rlnd 60o rcspectivBly with the turgerttial velociff: Deterirriue;

(i) the volume flo*"dt.,

(ii) the polver developecl, and (iii) tire hydraulic efficiency 083 c. Write short notes on ftany twol

I(i) Draft tube (ii) I'{a[n and operating characteristics of a hyilraulic turbine

(iii) Cavitation in tu{bines OBI

4 a" Draw a neat sketch r:[ centrifugal pump and explairi ffdvt it'operates. ' 1 5ll fifloR

4 b. Write a ncte on centiifirgai purrrp troubles and its remeclies 16il

5 a. (i) Pind the amount $ work saved against friction by fitting air vessel in a sirrgle08 stage reciprocatingipump.

(ii) Define the terms CIlip and cavitation witlt regards to reciprocating purnp. 0B5 b. A single acting reoig,irocating plrmp has a pJunger of d.ianieter 80 mm and stroke length 150mm. It takes i'rs suppty ftwater frorn a sump 3 m beiovr the pump through a pipe 4.5 m long 30mm diameter, It deliversirvater to a tark 12 m above the pump through a pipe 25 mm diameter

I

snd 15 m long. If the separation occurs at 78.48 kN/m2 below atmospheric pressure; finC themaxintum speed at wnic{ the pump may be operateri without separation, assume plurrger to havesirnple hannonio n:stion.l 08.5 c. Explain with a neat sfietch the working of

(i) hyclraulic couplinj (ii) Air liff. pump 0B


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CSVTU

Time: Three Hours

Code: ME 09514B. Tech. (Fifth Semester) Examination hlov-Dsc 2009

Subject: Fluid MachineryBranch: Mechanical Engg.

Max Marks: 80

Min Pass Marks: 28Note:

Q,l

Solve all the questions Internal Choice(s) are given. Assume suitable data if required.

Part'a' is compulsory. Solve either Part b or Part c.

If the velocity distribution in the boundary layer is given by +=2rl-rl'u*where ry =4........... (with all usual notations). Obtain the expression of boun{ary6

layer thickness at any location; shear drag (local)coefficient and Average dragcoefficient over the plate.

What is Van Karman Integral momentum equation? Derive it's formula.A flat plate 2m long and 1.5m wide is towed at 30 km/hr in water. The drag and liftcoefficient are 0.2 and 0.6 respectively. Calculate

-(i) the resultant force on plate(ii) the power required to keep the plate in motion.

Q.2 Part 'a' is compulsory. Solve either Part b or Part c.(a) (i) V/hV Pelton turbine is known as impulse turbine.

(ii) What will happen if splitter does not function properly?(iii)Showthat Vr2: Vrl in Pelton turbine (with usual notation)(iv) What is hydraulic loss in Pelton turbine, in which part and'why it takes place?

t0

06b)

".H

06

10

',The net hFl

ead on the Pelton wheel is 55 1m and discharge through the jet is 0.05|m3/s.L,If the Pelton wheel has velocity (Blade velocity) of 22 m/s, find the power

developed by the wheel. Assume outlet blade angle 150 and

Cv for jet = 0.98. Neglect the blade friction. 06Vvr

A vertical Jet is issuing upwards from a nozzle with velocity of l1 nVs. The fluid isoil ( p= 800 t gl*') and the nozzle exit diameter is 7,5 cm. A flat horizontal plate

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3\f

(c)


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Q.3

(a)

bJof weight 400 N is supported by means of Jet only. Determine the equilibriumheight of the plate above nozzle exit at which it is balanced. Neglect all losses.

Partoa'is compulsory. Solve any one Part b or c.

(i) What will happen if a draft tube from the Francis turbine is removedo other

conditions remain unchanged ?(ii) How is the guide blade passage, why it is so?(iii)Whether Vr2 is higher lower or equal to Vr1 and why in Francis turbine.

(iv) What is the main difference between the Kaplon and Propeler turbine, which is

more efficient.

An inward flow reaction turbine has an inlet guide vane angle of 300 and inlet Blade

angle of 1200. The breadth of the runner at inlet is a quarter of the diameter andthere is no whirl velocity at outiet. The net head is 15 m and speed is 1000 rpm. The

hydraulic and overall efficiencies arc 88Yo and 85% respectively. Find the power

developed by turbine.J.. , '*l ;(c) A Francis Turbine has an inlet diameter of irh and an outlet diameter of 1.2 m. The

runner rotates at a speed of 250 rpm with a discharge of 8 'rir3/sec. The Vanes areradia,! at- the inlet-and the-discharge is radial-af outlet. Calcuiatd the guide Vane

angle at the inlet and blade angle at the outlet.

Q.4 (a) How the height of pump from sump level is decided. Whether there is any limitation

of location of pump from sump level (i.e. height), justify your answer\mathematically.

il

, (.bl) The diameter of an impeller of a centrifugal pump is 350 mm with,outer width ofl," 50 inm. tump runs at tdbO rpm against a total head of'15 m. If Vane angle at outlet

is 350 and manometric efficiency is 80% Determine:r

(i) Velocity of flow at SuUet (ii) velocity of wx#leaving the Vane (iii) Anglemade by absolute velocity at outlet with direJHon of motion.

OR(c) A centrifugat pump lifts water under a static fr."a ;b i"t m of which 4 m is suctionhead. Suction and delivery pipes are both of 150 mm diameter having lengths suchthat they cause head loss of 1.5 m and 7 m in suction and delivery pipesrespectively. Impeller dia and width at outlet are 38 cm and 2:.5 mmrespectively.

06

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06

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N

Pump speed is tZijO rpm, outlet Blade angle is 380. and manometric efficiency is80%. Determine the discharge and pressure at suction and delivery sides of pump. 10

Q.5 (a) What are the causes of, acceleration head in rbciprocating pump? Why it is notpresent in centrifugal pump. How acceleration head governs the speed and discharge

of the reciprocating pump. Derive the formula for acceleration head in suction pipe.Whether it is positive or negative. 06

OR

(b) Explain briefly the working of torque converter, also draw characteristic curve. 06(c) Following are the data for a single acting single cylinder reciprocating pump -

stroke:400 mm LSpeed: 30 rpm r{Dia of piston:200 mm 9static suction head:3 m ltsstatic delivery head:29 p ltdlength of suction pipe: 5 m Lg

length of delivery pipe :20 m LaDiaof suctio-1nine: 100 mm 3s )':

Dia of delivery pipe: 100 ** dt

,Darcy's friction factor for both pipe : 0.015 $Atm pressure: 10 m of water. Hat ^Determine the pressure headq at the beginning, middle and end of delivery stroke,

work done during the suction and delivery strokes and the power required to drive

l0he pump.


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,ilsvgil

'F;sme: EEeree F{saprs

F{*fe: SsE.ve afty tw* parts of, eaeh question.

B. Eech. { F'ifth Semester} Hxaminaion Apr-May 20lSSubj ect: FEuid VlachineryBranch: HEechanical Engg.

Code: ME 09514

Max Marks: 80

Min Pass Marks: 28

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Q.2 ia)

ibi

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a 1 { Cutruiate the Displacement thickness and momentum thickness in terms of nominalthickness ( t ) of boundary iayer, whose velocity profile is

Lt-

3 izj -1[a)t.... ...with ztsusctl nctation,r* Zi,b) 2l\6)(b) Calcuiate the friction drag on one side of a flat plate 15 cm wide and 45 cm long

placed iongitudinally in a stream of oil of relative density 0.925 and kinematicviscocity 0.9 stoke, flowing with free stream velocity of 6 m/s. Aiso find the boundaryla3rer tirickness and shear stress at tratiing ecge.

A chimney has a diameter of 2.5 m and is 50 m tall. Calculate the Bending moment atthe base of chimney when air blsws across it at 80 km/hr. -,.

or t - \Take Ce: 0.33 md pof air :7.2Kg1m3. ' 1-"" 08

.Jl rA 10-cm diameter jet of water strikes a curved vane with velocity of 25 m/s. The iniet'/nangie of vane is zero and outlet angle is)30u. Determine the resultant force on the vane,

when the vane is stationary.

Show that the efficiency of Pelton turbine is maximum when speed Ratio

A Pelton wheel 2.5 mdiameter operates under the following conditions:Net available head:300 m,

speed:300 rpm

Cv:0.98,

Blade friction coefficient : 0.95Jet is deflected by i650.Diameter of Jet :20 cmMechanical effriiency : 0.95Determine the power-d,e-veloped by turbine and hydraulic efficiency.

Q^3 {a) (i) Exptrain function of draft tube.

08

08

is 0.5. 08

08

04

04ii) What are differences between an impuise arrtd aReaction turbine?

PTO


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. -''1- "{t dlYlbT An inward flow reaction turbine has inlet and outlet diameters of 1.2 and 0.61nrespectively. The breadth at inlet is 0f5 m and at outlet it is 935 m. At a speed of 250rpm. The relative velocity at entrance is 3.5:n/s. The vane is radial at entry. Calculate:(i)Absoiute velocity at entrance and it's inclination to the tangent of the runner.

{ii)Discharge (iii) Flow velocity at outlet.

-4d The output of a Francis turbine is 8 MW when discharge is :O mjisec and speed 200rpm. The diameter of the runner at inlet is 3m and breadth of openings at inlet is 0.9 m.

Find the guide blade angle. The outlet is without whirl. Neglect the mechanical losses.

(i) Expiain "Priming" of a centrifugal pump. -,.'{ii;E:


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AICTE

Time: Three Hours

B.Tech (Sixth Semester) Examination Nov-Dec. 2008Subject: Fluid Mechanids and Machines

Branch: Mechanical Engineering

Code:086025,.S

Max Marks:100Minimum Pass Marks:35

NOTE: Solve all the qaestioni. Internal choice is mentioned with question'

Q.1 Ig) A stationery vane having an Inlet angle of zero degree and outlet angle of 25"receives water at velocity of 25mls..determines the components of force acting on

it in the direction of the jet velocity and normal to it.

(ii) If the vane mentioned above is moving with velocity 20mls in the direction of. jet calculate the forcqcomponents in the direction of vane velocity and across it.

Also calculate the work done and power developed per Kg of flow.

OR

O) , A jet of water having a velocity of 40m/s strikes a curved rSo., which is movingwith velocity of 20m/s. The jet makes an angle of 3O"with the direction of motion

of vane at inlet and leaves at an angle of 90o to the direction of motion of vane at

outlet. Determine the vane angies at Inlet and Outlet. Draw the velocity Triangies.

Q.2 Solve any two partsr(Q/ A truck having projected area of 5.5n] travelling at 70Km&r has a totai

resistance of 2000N of this 20% is due to rolling friction and l0Vo due to surface

friction. The rest is due to drag find the drag coefficient. Take p :1.22Kg1m3 far

air. I o(b) Find the optimum speed ratio. At which wheel efficiency is maximum. For pelton

10Turbine.

g) A pelton wheel has gross head of 510m. One-third of gross head is lost in frictionin penstock. The discharge is 2.2m3ls and jet is deflected by 165" . Determine thehy&aulic efficiency of pelton wheel. l0

(a) Explain the purpose of fitting a draft table to Francis turbine. What will happen ifdraft tube is removed from Francis Turbine?

20

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Q,3

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(b)

(c)

A Francis turbine works at 450rpm under a head of 120m. It's diameter at illet is1.2m and flow area is 0.4m2. The angle made by absolute and relative velocitiesat inlet are 20o and 60o respectively with the tangential velocity. Determine the

.powerdeveloped and hydraulic effi.ciency.

oR+An inward flow reaction turbine has an extemal diameter of lm and its breadth atinlet is 250mm. If the velocity of flow at inlet is 2mls find the discharge;assuming l0% of the flow area is blocked by blade thickness. If the speed of therunner is 210rpm and guide blade angle is 10o, find the vane angle at inlet. wheelvelocity at inlet and absolute velocity of water at inlet. 12What is priming of a centrifugal pumps, why is it necessary. 06A centrifugal pumpito air.rr*ge 0.118 m3/s at a speed of 1450 rpm against ahead of 25m. The impeller diameter is 250mm, its width at outlet is 50 mmmanometric efficiency is 75%. Determine the vane angle at the outer periphery ofthe impeter.

L4

OR

Th6'impetei of a centrifugdf p-ump having extemal and internal

fm qpaper nit raipur mech 5th sem

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