关键词: 气动力计算;比热;压气机效率

Abstract: Along with the continuous increase of pressure ratios of real compressors,the error of efficiency calculation with constant specific heat isentropic index k=1.4 becomes greater and greater. In case that the pressure ratio, initial and final temperatures are given or experimentally measured,a correct method of varying specific heat compressor efficiency calculation is given,and results of illustrations for pressure ratios from 5 to 30 by steps are tabulated.An existing paper determining the isentropic index simply through initial and real final temperatures is shown to give appreciable errors in efficiency, being even almost of same order of magnitude as with constant specific heat.In engineering,the constant specific heat practice has been followed habitually for a long time.A simple and convenient way of calibration remains to be studied.

Key words: Aerodynamic computation;Specific heat;Compressor efficiency