Bir eş merkezli çift milli turbofan motorunun optimal performansına ısı kaybının etkisi

Recently, many researches have been focused on performance optimization of thermal systems. It is observed that the effect of heat losses on the performance of aircraft engines in terms of energy, exergy and environmental performance have not been studied sufficiently. Therefore, in this thesis, the effect of heat leakage on the optimal performance of a twin-spool turbofan engine has been studied. Selected four design parameters are total compressor pressure ratio, fan pressure ratio, by-pass air ratio and maximum turbine inlet temperature; also six performance indicators are coefficient of ecological performance, overall efficiency, exergy destruction factor, thrust specific fuel consumption, specific thrust and entropy generation rate. Two different heat leakages have been considered in the thesis; first one is heat leakage from the combustion chamber to the surrounding by-pass air through the combustion chamber wall, and the second one is from by-pass air to the very cold ambient air. It has been concluded that effect of the first heat leakage is more significant than the second one, effect of heat leakage is not linear, and heat leakage affects the optimum values of design parameters. Also, performance indicators based on the Second Law of Thermodynamics are affected by the first heat leakage more significantly than the other performance indicators based on the First Law of Thermodynamics. This is due to the high irreversibility of heat loss from high temperature combustion chamber resulting with high entropy generation rate, hence high exergy destruction rate.