SRM University 2008 B.Tech Electrical and Electronics Engineering - Question Paper

B.Tech (PT) DEGREE EXAMINATION,DECEMBER 2008
1st Semester
PCE218-FLUID MACHANICS AND MACHINERY
Time:3Hrs Max.marks:100
Answar ALL Qustions
PART-A(10*2=20Marks)
1.Define the terms:Density and specific quantity.

2.state the Newton's legal regulations of viscosity.

3.state Bernoullis theorem as applicable to fluid flow.

4.Define :potential function.

5.What are the losses expected by a fluid when it is passing through a pipe?

6.Differentiate the Francis and Kaplan turbines.

7.what is the function of spear and nozzle in pelton wheel?

8.Define:Hydraulic efficiency.

9.what is meant by pump?

10.What are reaction turbines ?Give examples.

PART-B (5*16=80 Marks)
11.a.i If the velocity distribution of over a plate is provided by U=2/3Y-Y^2 in which 'U' is the velocity in m/s and distance 'Y'in meter above the plate,determine the sher stress at Y=0 and Y=0.15 m,the dynamic viscosity of fluid is 8.63 poises.

ii. discuss Dynamic viscosity,Kinematic viscosity and capillarity.
(OR)
b.i The space ranging from 2 parallel plates 0.5 mm apart is filled with minarel oil.A force of 15 N is needed to pull the upper plate at a constant Velocity of 0.6 m/s.Calculte the viscosity of oil ,if the area of the upper plate is 2*10^6 mm^2.find also the kinematic viscosity of the oil if it is relative dencity is 0.8.

ii.Explain surface tension in
(i) liquid droplet (ii)Soap bubble


12.a.For the subsequent stres functions,determine the potential function
(i)U=(3/2)(x^2-y^2)

(ii)y=-8xy
(OR)
b.Explain continity formula for flow in cartesian co-ordinates.

13.a.i.Water is flowing through a pipe of diameter 200 mm with a velosity of 3.5 m/s .if the co-efficient of friction is provided by f=0.008+0.07/(Re)^0.25,Where Re-Reynolds number.Find the head loss due to friction for a length of 6.5 m. Take kinematic viscosity of water is 0.014*10^-4 m^2/s.

ii.Water is flowing through a pipe of 250 mm diameter and 60 m long at a rate of 0.3 m^2/s.Find the head loss due to friction .Take kinamatic viscosity of water as 0.012 strokes.
(OR)
b.Two reservoirs with a diference in water surface elevation of 15m are connected by a pipeline ABCD that consist of 3 pipes AB,BC&CD joined in series .pipe AB is10cm in diameter,20 m long and has a value of friction factor (f)=0.02,pipeBC is of 16 cm diameter,25m long and has f=0.018,pipe CD is of 12cm dia15 m long and has f=0.02. Take junction with reserviors and ranging from the pipes are abrupt.Determine the rate of flow for the subsequent cases:(i)neglecting minor losses (ii)considering minor losses also.

14.a.A centrifugal pump running at 900 rpm has impeller diameter of 500 mm .The blade angle at outlet is 35 degree with the tangent.Determine assuming zero whirl at inlet ,the inlet blade angle.Al so compute the absolute velocity at outlet and its angle with the tangent.the flow velocity is constant at three m/s,Also compute the manometric head.
(OR)
b. An axial flow pump running at 600 rpm delivers 1.4 m^3/s againct a head of 5m. The speed ratio is 2.5. The flow ratio is 0.5.The overall efficiency is 0.83.Determine the power needed and blade angles at the root and tip and the diffuser blade inlet angle .inlet whirl is zero.

15.a.Explain with neat sketches:
(i)pelton turbine (ii)Francis turbine
(OR)
b.The jet velcity in a pelton turbine is 65 m/s .the peripheral velocity of the runner is 25 m/s .the jet is deflected by 160 degree by the bucket.determine the power developed and hydraulic efficiency of the turbine for a flow rate of 0.9 m^3/s.The blade friction co-efficient is 0.9.

Earning:   Approval pending.