Compressors, Gas Turbines and Jet Engines A closed gas turbine in which fuel is burnt directly in the air is not possible because of High friction losses Paucity of O2 Increasing gas temperature High specific volume High friction losses Paucity of O2 Increasing gas temperature High specific volume 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 = (p₁ + p₃)/2 P₂ = Pa × p₃/p₁ p₂ = p₁. p₃ p₂ = Pa p₃/p₁ p₂ = (p₁ + p₃)/2 P₂ = Pa × p₃/p₁ p₂ = p₁. p₃ ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines In a closed cycle gas turbine, the air is compressed Isentropically Polytropically Isothermally None of these Isentropically Polytropically Isothermally None of these ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines Phenomenon of choking in compressor means Increased inclination of chord with air steam Fixed mass flow rate regardless of pressure ratio No flow of air Reducing mass flow rate with increase in pressure ratio Increased inclination of chord with air steam Fixed mass flow rate regardless of pressure ratio No flow of air Reducing mass flow rate with increase in pressure ratio ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines If p₁, is the pressure of air entering the L.P. cylinder and p₂ is the pressure of air leaving the L.P. cylinder (or inter-cooler pressure), then the ratio of cylinder diameters for a single acting, two stage reciprocating air compressor with complete intercooling is given by (where D₁ = Dia. of L.P. cylinder, and D₂ = Dia. of H.P. cylinder) D₁/D₂ = p₁/p₂ None of these D₁/D₂ = p₁ p₂ D₁/D₂ = p₂/p₁ D₁/D₂ = p₁/p₂ None of these D₁/D₂ = p₁ p₂ D₁/D₂ = p₂/p₁ ANSWER DOWNLOAD EXAMIANS APP
Compressors, Gas Turbines and Jet Engines For minimum work in multistage compression, assuming same index of compression in all stages Work done in all stages should be equal Work done in subsequent stages should decrease Work done in first stage should be more Work done in subsequent stages should increase Work done in all stages should be equal Work done in subsequent stages should decrease Work done in first stage should be more Work done in subsequent stages should increase ANSWER DOWNLOAD EXAMIANS APP