STUPIDSID
1(b)
Define specific speed od a turbine. Derive an expression for specific speed of a pump.
8 M
1(c)
Tests on a turbine runner 1.25 m in diameter at 30 m head gave the folllowing results: Power developed 736 KW speed 180 rpm, Discharge 2.7m3/s
Find the diameter, speed and discharge of a runner to operate at 45 m head and give 1472 kW power at the same efficiency. What is the specific speed of both the turbines?
Find the diameter, speed and discharge of a runner to operate at 45 m head and give 1472 kW power at the same efficiency. What is the specific speed of both the turbines?
7 M
2(a)
For a compression process, show that the isentropic efficiency is given by,\( \eta _c=\dfrac{P_r^{\dfrac{\gamma-1}{\gamma}}-1}{P_r^{\dfrac{\gamma-1}{\gamma\eta/1}}-1} \)/
8 M
2(b)
Define the following for a compression process: i) Total to toal efficiency ii) Static to static efficiency
4 M
2(c)
A 16 stage axial flow compressor is have a pressure ration of 6.3 and tests have shown that a stage efficiency of 89.5% can be obtained. The intake conditions are 288 K and 1 bar pressure. Find i) Overall efficiency ii) Polytropic efficiency iii) Preheat factor
8 M
3(a)
Defineefine degree of reaction (R). Derive an expression relating utilization factor with degree of reaction.
10 M
3(b)
Water approaches the impeller of a mixed flow pump with an absolute velocity having tangential and axial components each of 17 m/s. At the rotor exit the radial and tangential components of the absoulte velocity are 13 m/s and 25 m/s respectively. The tangential blade speed at inlet and exit are 12 m/s and 47 m/s. Find i) Change in enthalpy across the rotor.
ii) Total change in pressure across the rotor
iii) Change in static pressure.
iv) Degree of reaction.
ii) Total change in pressure across the rotor
iii) Change in static pressure.
iv) Degree of reaction.
10 M
4(a)
The internal and external diameters of the impeller of a centrifugal pump are 20 cm and 40 cm respectively. The pump is running at1 200 rpm. The Vane angle of impeller at inlet is 20*. The water enters the impeller radially and velocity of flow is constant. Calculate workdone by the impeller/ kg of water for the following two cases: i) When vane angle at outlet is 90*.
ii) When Vane angle at outlet is 100* Draw the corresponding velocity triangles.
ii) When Vane angle at outlet is 100* Draw the corresponding velocity triangles.
10 M
4(b)
Derive head-capacity relationship for centrifugal pumps and explain the effect of discharge angle on it.
10 M
5(a)
Write note on compounding of steam turbines and explain any two types corresponding with neat sketches.
10 M
5(b)
A simple impulse turbine has a mean blade of 200 m/s. The nozzles are inclined at 20* tot the plane of rotation of the blades. The steam velocity from nozzles is 600 m/s. The turbine uses 3500 kg/hr of steam. The absolute velocity at exit is along the axis of turbine. Determine: i) Inlet and exit angles of blades.
ii) Power output of turbin.
iii) Diagram efficiency.
ii) Power output of turbin.
iii) Diagram efficiency.
10 M
6(a)
With a neat skecth, explain the working of Kaplan turbine. Mention the functions of draft tube.
10 M
6(b)
The penstock supplies water from a reservoir to the Pelton wheel with a gross head of 500 m. One third of the gross head is lost in friction in the penstock. The rate of flow of water through the nozzle fitted at the end of penstock id 2 m3/s. The angle of deflection of the jet is 165*. Determine the power given by the water to the runner and also hydraulic efficiency of the Pelton wheel. Take speed ration 0.45 and Cv1.0
10 M
7(a)
Derive an expression for minimum starting speed of centrifugal pump.
6 M
7(b)
Define the following with respect to centrifugal pumps: i) Manometric head ii) Manometric efficiency iii) Overall efficiency.
6 M
7(c)
A centrifugal pump having outer diameter equal to two times the inner diameter and running at 1000 rpm works against a total head of 40 m. The velocity of flow through the impeller is constant and equal to 2.5 m/s. The vanes are set back at and angle of 40* at outlet. If the outer diameter of the impeller is 500 mm and width at outlet is 50 mm. Determine
i) Vane angle at inlet ii) Workdone by impeller on water/s iii) Manometric efficiency.
i) Vane angle at inlet ii) Workdone by impeller on water/s iii) Manometric efficiency.
8 M
8(a)
Explain the phenomenon of surging and stalling in centrifugal compressors.
6 M
8(b)
With a neat sketch, explain the paris of a axial flow compressor.
6 M
8(c)
An axial flow compressor has the following data entry condition 1 bar, 20*C degree of reaction 50% mean blade ring diameter 36 cm, Rotational speed 18000 rpm blade height at entry 6 cm, Blade angle at rotor and stator exit 65* axial velocity 180 m/s mechnical efficiency 0.967. Find i) Guide balde angle at outlet. ii) Power required to drive the compressor.
8 M
More question papers from Turbo Machines