**GTU previous question papers**

**GUJARAT TECHNOLOGICAL UNIVERSITY**

**BE- V****th ****SEMESTER–EXAMINATION – MAY/JUNE – 2012**

**Subject code: 151903 **

**Subject Name: Fluid Power Engineering**

**Instructions:**

**1. Attempt all questions.**

**2. Make suitable assumptions wherever necessary.**

**3. Figures to the right indicate full marks.**

**Q.1 (a) **Prove that head loss due to friction is equal to one third of total head

inlet for maximum power transmission through nozzle.** **

**(b) **Explain the following terms : (1) Major losses (2) Minor losses and (3)

Equivalent pipe** **

**Q.2 (a) **A jet delivers water at the rate of 60 liters per second with velocity 30

m/s. The jet strikes tangentially on the vane moving in the direction of

the jet with the velocity of 15 m/s. The vane is so shaped that if

stationary it would deflect the jet through an angle 50°. Calculate: (1)

angle made by absolute velocity at outlet and (2) work done per sec.** **

**(b) **Show that in case of jet striking the flat plates mounted on wheel, the

efficiency will be maximum when the tangential velocity of wheel is half

of the jet.** **

**OR**

**(b) **A jet of water of 30 mm diameter, strikes on the hinged rectangular plate

weight 100 N at the center of the plate. The velocity of the jet is 8 m/s.

Calculate: (1) angle through which the plate will swing, and (2) force

must be applied at the lower edge of the plate in order to keep the plate

vertical.** **

**Q.3 (a) **Explain the following terms with reference to water turbines. Give

expression of each efficiencies.

(1) Hydraulic efficiency (2) Mechanical efficiency and

(3) Overall efficiency** **

**(b) **The following data is related to Pelton wheel turbine

(1) Heat at the base of the nozzle=80 m

(2) Diameter of the jet = 100 mm

(3) Discharge of the nozzle=0.30m3/s

(4) Power at the shaft=206 kw and

(5) Power absorbed in mechanical resistance= 4.5 kw

Determine: (1) power lost in nozzle and (2) power lost due to hydraulic

resistance in the runner.** **

**OR**

**Q.3 (a) **Why governing of water turbine is required? Explain governing of any

one hydraulic turbine with neat sketch.** **

**(b) **Francis turbine designed to develop 160 kw working under a head 10 m

and running at 200 rpm. The hydraulic losses in turbine are 15% of

available energy. The overall efficiency of turbine is 80%. Assume flow

ratio=0.94 and speed ratio=0.25. Calculate: (1) guide blade angle and

runner vane angle at inlet and (2) diameter and width at inlet.** **

**Q.4 (a) **Enlist the various types of impeller used in centrifugal pump and explain

any one from it with a neat sketch .** **

**(b) **Find the power required to drive a centrifugal pump which delivers 0.04

m3/sec of water to a height of 20m through a 15 cm diameter pipe and

100 m long. The overall efficiency of the pump is 70% and co efficient

of friction *f*=0.015 used in Darcy’s equation.** **

**OR**

**Q.4 (a) **Give classification of Reciprocating pump. Draw neat sketch of single

acting reciprocating pump

** **

**(b) **Write a short note on Submersible pump. ** **

**Q.5 (a) **Derive an expression for the optimum value of the intercooler pressure

in a two stage reciprocating air compressor for perfect inter cooling condition.** **

**(b) **A centrifugal air compressor has a pressure ratio of 4:1 with an

isentropic efficiency 88% when running at 14000 rpm and including air

at 25° C. Curved vanes at inlet give the air a pre-whirl of 18° to axial

direction at all radii and the mean diameter of eye is 245 mm. The

absolute air velocity at inlet is 120 m/s. Impeller tip diameter is 580 mm.

Calculate slip factor.** **

**OR**

**Q.5 (a) **With a suitable sketch explain the working principle of an axial flow

compressor. Draw the stage velocity triangles.** **

**(b) **Explain working of Differential hydraulic accumulator with neat sketch. ** **

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