吸气式发动机试验中空气流量的计算

Calculation of air mass flow in air breathing engine test

关键词:  发动机试验  空气流  质量流量  流量测量  计算方法  计算误差

Key words:  Engine test  Airflow  Mass flow rate  Flow rate measurement  Calculation method  Calculation error

摘要:

为降低吸气式发动机试验中空气流量测量的计算误差 ,在分析三种常用的测量空气流量计算方法的基础上 ,提出了可压流温比修正算法和无方法误差的程序计算法 ,分析了各种方法的适用范围和方法误差。同时 ,提出了空气湿度、直接加热污染和管壁受热等对物性参数和管径的修正方法。结果表明 ,程序计算法没有误差 ,在高超声速飞行的模拟试验中尤为适用 ;可压流温比修正法可以在工程上代替程序计算法 ,在广阔的压比和来流总温条件下 ,其方法误差可以忽略。

Abstract:

To reduce the calculation error of air flow measurement in air breathing engine test,based on three normal calculation methods,two new methods was presented:temperature ratio modify method of compressible flow and program calculation method which has no methodological error.The applied range and the methodological errors of all methods were also analyzed.At the same time,the effects of air humidity,direct heating pollution,and the heat expansion on pipe wall were considered.The result shows that program calculation method has no methodolog1cal errol,and it is suitable for analog hypersonic flight test.The temperature ratio modify method can take the place of program calculation method in engineering;its methodological error can be ignored in wide range of pressure ratio and airflow temperature.