Radial flow compressor
Axial flow compressor
Roots blower
Reciprocating compressor
A. Radial flow compressor
They can generate very high thrust
They have high propulsion efficiency
These engines can work on several fuels
They are not air breathing engines
Small quantities of air at high pressures
Large quantities of air at high pressures
Small quantities of air at low pressures
Large quantities of air at low pressures
It requires very big cylinder
It does not increase pressure much
It is impossible in practice
Compressor has to run at very slow speed to achieve it
Larger air handling ability per unit frontal area
Higher pressure ratio per stage
Aerofoil blades are used
Higher average velocities
0.1 to 1.2 m³/s
0.15 to 5 m³/s
Above 5 m³/s
None of these
Actual volume of the air delivered by the compressor when reduced to normal temperature and pressure conditions
Volume of air delivered by the compressor
Volume of air sucked by the compressor during its suction stroke
None of the above
The compression ratio in each stage should be same
The intercooling should be perfect
The workdone in each stage should be same
All of the above
Low frontal area
Higher thrust
High pressure rise
None of these
The ratio of the discharge pressure to the inlet pressure of air is called compressor efficiency
The compression ratio for the compressor is always greater than unity
The compressor capacity is the ratio of workdone per cycle to the stroke volume
During isothermal compression of air, the workdone in a compressor is maximum
0.1 %
0.5 %
1.0 %
5 %
Increase in flow
Decrease in flow
Increase in efficiency
Increase in flow and decrease in efficiency
Large gas turbines use radial inflow turbines
Gas turbines have their blades similar to steam turbine
Gas turbine's blade will appear as impulse section at the hub and as a reaction section at tip
Gas turbines use both air and liquid cooling
Decrease
Increase
Remain same
Does not change
Thrust power and fuel energy
Engine output and propulsive power
Propulsive power and fuel input
Thrust power and propulsive power
A propeller system
Gas turbine engine equipped with a propulsive nozzle and diffuse
Chemical rocket engine
Ramjet engine
One air stream
Two or more air streams
No air stream
Solid fuel firing
Equal to
Less than
More than
None of these
A.C. electric motor
Compressed air
Petrol engine
Diesel engine
Less
More
Same
May be less or more depending on ambient conditions
Indicated power
Brake power
Frictional power
None of these
Gauge discharge pressure to the gauge intake pressure
Absolute discharge pressure to the absolute intake pressure
Pressures at discharge and suction corresponding to same temperature
Stroke volume and clearance volume
Equal to
Less than
Greater than
None of these
Turbojet
Turbo-propeller
Rocket
Ramjet
Directly proportional to clearance volume
Greatly affected by clearance volume
Not affected by clearance volume
Inversely proportional to clearance volume
Less
More
Same
May be less or more depending upon speed
Compressor capacity
Compression ratio
Compressor efficiency
Mean effective pressure
200°C
500°C
700°C
1000°C
Compressor efficiency
Isentropic efficiency
Euler's efficiency
Pressure coefficient
p₂ = p₁ × p₃
p₂ = p₁/p₃
p₂ = p₁ × p₂
p₂ = p₃/p₁
Reheating
Inter cooling
Adding a regenerator
All of the above