Compressors, Gas Turbines and Jet Engines Isothermal compression efficiency, even when running at high speed, can be approached by using Fully insulating the cylinder Both (A) and (B) above Cold water spray Multistage compression Fully insulating the cylinder Both (A) and (B) above Cold water spray Multistage compression ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines For a two stage compressor, if index of compression for higher stage is greater than index of compression for lower stage, then the optimum pressure as compared to ideal case will Increase Decrease Remain unaffected Other factors control it Increase Decrease Remain unaffected Other factors control it ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines Axial flow compressor has the following advantage over centrifugal compressor Higher pressure ratio per stage Higher average velocities Larger air handling ability per unit frontal area Aerofoil blades are used Higher pressure ratio per stage Higher average velocities Larger air handling ability per unit frontal area Aerofoil blades are used ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines The overall isothermal efficiency of compressor is defined as the ratio of Isothermal h.p. to the BHP of motor Work to compress air isothermally to work for actual compression Power to drive compressor to isothermal h.p. Isothermal h.p. to adiabatic h.p. Isothermal h.p. to the BHP of motor Work to compress air isothermally to work for actual compression Power to drive compressor to isothermal h.p. Isothermal h.p. to adiabatic h.p. 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 = 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 p₂ = (p₁ + p₃)/2 ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines Intercooling in gas turbines Increases net output and thermal efficiency both Decreases net output and thermal efficiency both Decreases net output but increases thermal efficiency Increases net output but decreases thermal efficiency Increases net output and thermal efficiency both Decreases net output and thermal efficiency both Decreases net output but increases thermal efficiency Increases net output but decreases thermal efficiency ANSWER DOWNLOAD EXAMIANS APP
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