Compressors, Gas Turbines and Jet Engines High air-fuel ratio in gas turbines Improves thermal efficiency Reduces exhaust temperature Increases power output Do not damage turbine blades Improves thermal efficiency Reduces exhaust temperature Increases power output Do not damage turbine blades ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines Volumetric efficiency of air compressors is of the order of 40 - 50% 70 - 90% 60 - 70% 20 - 30% 40 - 50% 70 - 90% 60 - 70% 20 - 30% ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines The overall isothermal efficiency of the compressor is defined as the ratio of Isothermal power to the shaft power or B.P. of the motor or engine required to drive the compressor Work required to compress the air isothermally to the actual work required to compress the air for the same pressure ratio Volume of free air delivery per stroke to the swept volume of the piston Isentropic power to the power required to drive the compressor Isothermal power to the shaft power or B.P. of the motor or engine required to drive the compressor Work required to compress the air isothermally to the actual work required to compress the air for the same pressure ratio Volume of free air delivery per stroke to the swept volume of the piston Isentropic power to the power required to drive the compressor ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines For a two stage reciprocating compressor, compression from p₁ to p₃ is with perfect intercooling and no pressure losses. If compression in both the cylinders follows the same polytropic process and the atmospheric pressure is pa, then the intermediate pressure p₂ is given by p₂ = (p₁ + p₃)/2 P₂ = Pa × p₃/p₁ p₂ = Pa p₃/p₁ p₂ = p₁. p₃ p₂ = (p₁ + p₃)/2 P₂ = Pa × p₃/p₁ p₂ = Pa p₃/p₁ p₂ = p₁. p₃ ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines With the decrease in compression ratio, the volumetric efficiency Decreases First decrease and then increase Does not change Increases Decreases First decrease and then increase Does not change Increases ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines In open cycle turbojet engines used in military aircraft, reheating the exhaust gas from the turbine by burning, more fuel is used to increase the None of these Efficiency of the engine Both (A) and (B) Thrust and range of aircraft None of these Efficiency of the engine Both (A) and (B) Thrust and range of aircraft ANSWER DOWNLOAD EXAMIANS APP
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