Gas Turbine And Jet Propulsion (GT&JP) Question Paper 2014 is the bput m.tech Mechanical Previous Questions of 2nd Semester in Mechanical Engineering (Heat Power Engineering). The prescribed book for GT & JP in M.Tech Second Semester is Gas Turbine by V.Ganesan (TMH Publication ). If you are doing M.Tech in Mechanical Engineering, then save or download this question.
Gas Turbine And Jet Propulsion Question Paper 2014
2nd Semester Regular/Back Examination
GAS TURBINE AND JET PROPULSION
BRANCH : HEAT POWER ENGINEERING Or Mechanical Engg.
Time: 3 Hours , Max Marks: 70
Answer Question No.1 which is compulsory and any five from the rest.
Q1 Answer the following questions: (2×10)
a) Define Engine Pressure Ratio (EPR) and Ram Pressure Ratio (RPR)
b) Write the expression for equivalent power (EP) of turboprop engine in terms shaft power (SP) and jet thrust (F).
c) What is the function of auxiliary power unit (APU) in civil aircrafts? .
d) Why a slip factor is introduced to nearly make the whirl velocity at impeller tip equal to the tip speed in a centrifugal compressor.
e) Write down three main advantages of axial flow compressors over the centrifugal compressors.
f) Write two basic important requirements for blade design in an axial compressor.
g) Define De-Haller number. Why it is important for axial compressors.
h) Define combustion efficiency.
i) What are major difference between the land-based gas turbines and the gas turbines used for aircraft applications.
j ) Draw a free hand graph to show the variation of pressure ratio with efficiency for an ideal gas turbine cycle taking different specific heats of air, such as y =1.4 and 1.66, respectively..
Q2. a) A gas which has a molecular mass of 39.9 and specific heat ratio of 1.67 is discharged through a nozzle. A normal shock wave occurs at section of the flow at which the Mach number is 25, the pressure is 40 kPa and temperature is -20°C. Find Mach number down steam of the normal shock.
b) For the above case, find the pressure and temperature downstream of normal shock .
Q3. a) An auxiliary turbine for use on a large airliner uses a single shaft configuration with air bled from compressor discharge for aircraft services. The unit must provide 1.5 kg/s bleed air and a shaft power of 200 kW. Calculate the total compressor air mass flow rate.
b) Calculate the power available with no bleed flow, assuming the following:
- Compressor pressure ratio : 3.8
- Compressor isentropic efficiency : 0.85
- Turbine inlet temperature : 1050 K
- Combustion pressure loss : 0.12 bar
- Turbine isentropic efficiency : 0.88
- Mechanical efficiency (compressor rotor) : 0.99
- Mechanical efficiency (driven load) : 0.98
- Ambient condition : 1 bar, 288 K
Q4 Define degree of reaction ( A ). Prove that for an axial flow compressor the degree of reaction is
A = Ca/2U (tanß1 + tanß2 )The symbols have the usual meaning.
Q5. a) A centrifugal compressor compresses 30 kg of air per second at a rotational speed of 15,000 rpm. The air enters the compressor axially, and the conditions at exit sections are radius=0.3 m, relative velocity of air at tip =100 m/s at the exit angle of 80°. Find the torque required to drive the compressor.
b) Find the power required to drive the compressor and ideal head developed.
Q6 Write Short Notes (Any Two)
a) Turboprop and turbo shaft engines
b) Procedure for turbine and compressor matching in turbojet engine. Your answer should be precise and step by step procedure.
c) Operating characteristics for centrifugal compressor