SPPU Mechanical Engineering (Semester 7)
Gas Turbine Propulsion
December 2016
Total marks: --
Total time: --
INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary


Solve any one question from Q.1(a,b) & Q.2
1(a) Write a note on ideal and actual Brayton cycle.
3 M
1(b) In a gas turbine plant, the suction occurs at 1 bar and 27&Deg;C. The air is compressed to 4 bar. Maximum temperature is 572°C. Find the air-fuel ratio. Assume isenttropic efficiency of compressor & turbine, as 85%. Take Cp for air & gases as 1.005 and 0.97kJ/kgK, respectively, C.V= 42MJ/kg.
7 M

2 Write notes on:
a) Rocket propulsion.
ii) Polytropic efficiency of compressor & turbine.
10 M

Solve any one question from Q.3(a,b) & Q.4(a,b)
3(a) Write a note on the various parameters affecting the flight performance.
4 M
3(b) Explain the working of turbofan engine.
6 M

4(a) Discuss Nozzle & difusser losses.
5 M
4(b) What do you understand by the term air-breathing engines? How are they classified?
5 M

Solve any one question from Q.5(a,b) & Q.6(a,b)
5(a) Explain the effect of nozzle angle on work output and effect of axial discharge in an axial flow turbine.
6 M
5(b) In a single axial flow turbine (impulse type), the expansion in the nozzle occurs from 4bar, 650°C to a press of 1 bar. The discharge angle is 15° The blade speed is 360m/s and the gas leaves the rotor blade in axial direction with a speed is 360m/s and the gas leaves the rotor blade in axial direction with a speed of 300 m/s. Assuming a nozzle efficiency of 96% Find:
i) Rotor blade angles at inlet and oulet.
ii) Utilization factor.
iii) Power developed for 25kg/sec of gas flow.
iv) Stage efficiency.
10 M

6(a) Discuss the performance curves of gas turbines.
6 M
6(b) Gas enters in an impulse turbine(1-stage) at a stagnation pressure of 4 bar while th exit static pressure is 1.18 bar. Stage exit velocity is 290m/s(axial) & nozzle efficiency is 96%. The blade velocity is 320m/s. The static head efficiency is 88%. The exit pressure from the nozzle is 1.25 bar. Find:
i) W.D. per kg of air.
ii) Nozzle angle.
iii) Blade inlet and outlet angle.
iv) Energy utilization factor for the rotor.
10 M

Solve any one question from Q.7(a,b) & Q.8
7(a) Explain the processes involved in an axial flow compressor with the help of T-s diagram.
6 M
7(b) Write notes on:
i) Flow coefficient &stage efficiency.
ii) Degree of reaction and workdone factor.
10 M

8 Write notes on:
a) Radial & axial flow compressors
b) Factors affecting pressure ratio.
c) Inlet & Outlet velocity triangle.
16 M

Solve any one question from Q.9(a,b) & Q.10
9(a) Explain the different types of combustion chambers used in gas turbines.
9 M
9(b) Write notes on:
i) Desirable features of combustion chambers of a gas turbine.
ii) Combustion chamber arrangements.
9 M

10 Write notes on:
a) Off-design characteristics of gas turbines.
b) Stability limits and combusion intensity.
c) Component characteristics of compressor &turbine.
18 M



More question papers from Gas Turbine Propulsion
SPONSORED ADVERTISEMENTS