Gas turbine works on
Brayton or Atkinson cycle
Carnot cycle
Rankine cycle
Erricson cycle
Correct Answer :
A. Brayton or Atkinson cycle
Related Questions
In jet engines, for the efficient production of large power, fuel is burnt in an atmosphere of
Vacuum
Atmospheric air
Compressed air
Oxygen alone
The ratio of isentropic work to Eulers work is known as
Compressor efficiency
Isentropic efficiency
Euler's efficiency
Pressure coefficient
The ratio of isentropic work to Euler work is known as
Pressure coefficient
Work coefficient
Polytropic reaction
Slip factor
Phenomenon of choking in compressor means
No flow of air
Fixed mass flow rate regardless of pressure ratio
Reducing mass flow rate with increase in pressure ratio
Increased inclination of chord with air steam
The velocity of air entering in a rocket is ________ as compared to an aircraft.
Zero
Less
More
Same
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
Work ratio of a gas turbine plant is ratio of
Net work output and work done by turbine
Net work output and heat supplied
Work done by turbine and heat supplied
Work done by turbine and net work output
Reheating in a gas turbine
Increases the thermal efficiency
Increases the compressor work
Increases the turbine work
Decreases the thermal efficiency
The volumetric efficiency of a compressor falls roughly as follows for every 5°C increase in atmospheric temperature
0.1 %
0.5 %
1 %
5 %
Axial flow compressor resembles
Centrifugal pump
Reciprocating pump
Turbine
Sliding vane compressor
Axial flow compressor has the following advantage over centrifugal compressor
Larger air handling ability per unit frontal area
Higher pressure ratio per stage
Aerofoil blades are used
Higher average velocities
The ratio of specific weight/h.p. of gas turbine and I.C engines may be typically of the order of
1 : 1
2 : 1
4 : 1
1 : 6
The indicated work per unit mass of air delivered is
Directly proportional to clearance volume
Greatly affected by clearance volume
Not affected by clearance volume
Inversely proportional to clearance volume
Ram compression in turbojet involves
Reduction of speed of incoming air and conversion of part of it into pressure energy
Compression of inlet air
Increasing speed of incoming air
Lost work
Only rocket engines can be propelled to space because
They can generate very high thrust
They have high propulsion efficiency
These engines can work on several fuels
They are not air breathing engines
Pick up wrong statement. Surging phenomenon in centrifugal compressor depends on
Mass flow rate
Pressure ratio
Change in load
Stagnation pressure at the outlet
The most efficient method of compressing air is to compress it
Isothermally
Adiabatically
Isentropically
Isochronically
In the axial flow gas turbine, the work ratio is the ratio of
Compressor work and turbine work
Output and input
Actual total head temperature drop to the isentropic total head drop from total head inlet to static head outlet
Actual compressor work and theoretical compressor work
Pick up the correct statement
Closed cycle gas turbine is an I.C engine
Gas turbine uses same working fluid over and over again
Ideal efficiency of closed cycle gas turbine plant is more than Carnot cycle efficiency
Thrust in turbojet is produced by nozzle exit gases.
The volume of air sucked by the compressor during its suction stroke is called
Free air delivery
Compressor capacity
Swept volume
None of these
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
If the clearance ratio for a reciprocating air compressor is 'K', then its volumetric efficiency is given by
1 - k + k (p₁/p₂)1/n
1 + k - k (p₂/p₁)1/n
1 - k + k (p₁/p₂) n- 1/n
1 + k - k (p₂/p₁) n-1/n
In jet engines, paraffin is usually used as the fuel because of its
High calorific value
Ease of atomisation
Low freezing point
Both (A) and (C) above
The power available for takeoff and climb in case of turbojet engine as compared to reciprocating engine is
Less
More
Same
May be less or more depending on ambient conditions
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 n₁ and n₂ are the indices of compression for the first and second stage of compression, then the ratio of workdone on the first and second stages (W₁/W₂) with perfect intercooling is given by
W₁/W₂ = n₂(n₁ - 1)/n₁(n₂ - 1)
W₁/W₂ = n₁(n₂ - 1)/n₂(n₁ - 1)
W₁/W₂ = n₁/n₂
W₁/W₂ = n₂/n₁
The workdone on a compressor will be minimum if air is taken from
The atmosphere
A source at 0°C
A source of low temperature air
A source of high temperature air
The capacity of compressor will be highest when its intake temperature is
Lowest
Highest
Anything
Atmospheric
The compressor capacity is defined as the
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 efficiency of roots blower ________ with the increase in pressure ratio.
Decreases
Increases
Does not change
None of these