热循环参数对发动机性能和费用的影响

EFFECT OF THERMODYNAMIC PARAMETERS ON PERFORMANCE AND COST OF TURBINE ENGINE

用统计方法给出了国产喷气发动机全寿命费用的估算模型 ,提出了全寿命费用率的概念 ,分别计算了发动机热循环参数和寿命提高后 ,推力、耗油率和全寿命费用率的变化情况。结果是 :增加涡轮前燃气温度可大幅度提高发动机性能 ,但费用也迅速增加 ,为使全寿命费用增加较少 ,必须提高发动机翻修寿命和总寿命 ,而单纯提高增压比则使发动机推力下降 ,全寿命费用率增加。

A method for estimating life cycle cost of aircraft turbine engine manufactured in China is provided on the basis of a statistic technology and a definition of life cycle cost ratio has been used.Changes in thrust,specific fuel consumption and life cycle cost have been calculated when thermodynamic parameters(π  k,T  3 and T  af )and mean time between overhauls of the engine increase.It was found that there was a marked growth of the engine thrust when T  3 increased,but life cycle cost ratio of the engine should,too,quickly grow.In order to make the growth of life cycle cost ratio acceptable for the Air Force,mean time between overhauls and total operation time of the engine must be lengthened.And a overhigh pressure ratio of the compresser often makes the thrust drop down and life cycle cost ratio grow up.