Open cycle gas turbine works on
Brayton or Atkinson cycle
Rankine cycle
Carnot cycle
Erricson cycle
Correct Answer :
A. Brayton or Atkinson cycle
Related Questions
Ramjet engine
Is self operating at zero flight speed
Is not self operating at zero flight speed
Requires no air for its operation
Produces a jet consisting of plasma
In axial flow compressor, exit flow angle deviation from the blade angle is a function of
Blade camber
Blade camber and incidence angle
Spacechord ratio
Blade camber and spacechord ratio
It is not possible to use closed gas turbine cycle in aeronautical engines because
It is inefficient
It is bulky
It requires cooling water for its operation
None of the above
In a high pressure compressor, the delivery pressure is
1 to 5 bar
5 to 8 bar
8 to 10 bar
10 to 15 bar
An air compressor may be controlled by
Throttle control
Clearance control
Blow off control
Any one of the above
Euler's equation can be used for
Radial flow compressors
Axial flow compressors
Pumps
All of these
A machine used to raise the pressure of air is called
Gas turbine
I.C engine
Compressor
Air motor
The intercooler pressure, for minimum work required, for a two stage reciprocating air compressor, is given by (where p₁ = Intake pressure of air, p₂ = Intercooler pressure, and p₃ = Delivery pressure of air)
p₂ = p₁ × p₃
p₂ = p₁/p₃
p₂ = p₁ × p₂
p₂ = p₃/p₁
Pick up the correct statement
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
Actual compression curve is
Same as isothermal
Same as adiabatic
Better than isothermal and adiabatic
In between isothermal and adiabatic
In a jet engine, the air-fuel ratio is
30 : 1
40 : 1
50 : 1
60 : 1
High air-fuel ratio in gas turbines
Increases power output
Improves thermal efficiency
Reduces exhaust temperature
Do not damage turbine blades
Mining industry usually employs following motive power
A.C. electric motor
Compressed air
Petrol engine
Diesel engine
The compressor capacity with decrease in suction temperature
Increases
Decreases
Remain unaffected
May increase or decrease depending on compressor capacity
With the decrease in compression ratio, the volumetric efficiency
Does not change
Increases
Decreases
First decrease and then increase
For an irreversible gas turbine cycle, the efficiency and work ratio both depend on
Pressure ratio alone
Maximum cycle temperature alone
Minimum cycle temperature alone
Both pressure ratio and maximum cycle temperature
The compression ratio for the compressor is always __________ unity.
Equal to
Less than
More than
None of these
A large clearance volume in a reciprocating compressor results in
Reduced volume flow rate
Increased volume flow rate
Lower suction pressure
Lower delivery pressure
Isothermal compression efficiency, even when running at high speed, can be approached by using
Multistage compression
Cold water spray
Both (A) and (B) above
Fully insulating the cylinder
Which of the following statement is wrong?
In a two stage reciprocating air compressor with complete intercooling, maximum work is saved.
The minimum work required for a two stage reciprocating air compressor is double the work required for each stage.
The ratio of the volume of free air delivery per stroke to the swept volume of the piston is called volumetric efficiency.
None of the above
The efficiency of jet engine is
Lower at low speed
Higher at high altitudes
Same at all altitudes
Higher at high speed
The volume of air delivered by the compressor is called
Free air delivery
Compressor capacity
Swept volume
None of these
Which of the following statement is correct as regard to centrifugal compressors?
The flow of air is parallel to the axis of the compressor
The static pressure of air in the impeller increases in order to provide centripetal force on the air
The impeller rotates at high speeds
The maximum efficiency is higher than multistage axial flow compressors
The net work input required for compressor with increase in clearance volume
Increases
Decreases
Remains same
Increases/decreases depending on compressor capacity
Which is false statement about air receivers?
These are used to dampen pulsations
These act as reservoir to take care of sudden demands
These increase compressor efficiency
These knock out some oil and moisture
Isothermal compression efficiency can be attained by running the compressor
At very high speed
At very slow speed
At average speed
At zero speed
Inter-cooling in multistage compressors is done
To cool the air during compression
To cool the air at delivery
To enable compression in two stages
To minimise the work of compression
The overall thermal efficiency of an ideal gas turbine plant is (where r = Pressure ratio)
r -1
1 - r -1
1 - (1/r) -1/
1 - (1/r) /-1
Ratio of indicated H.P. and brake H.P. is known as
Mechanical efficiency
Volumetric efficiency
Isothermal efficiency
Adiabatic efficiency
The maximum combustion pressure in gas turbine as compared to I.C. engine is
More
Less
Same
Depends on other factors