高度对航空发动机地面试验性能的影响

本文简要分析了海拔高度对航空发动机地面试验性能的影响和研究该影响的两种方法的优缺点.在此基础上提出了利用高空台压力调控的独特优势,通过不同进口压力对发动机定冲压比性能影响研究来确定其影响的研究方案.某型发动机的试验结果表明,在发动机冲压比1.6、风扇换算转速94.5%～96.5%条件下,进口总压在70～90 kPa之间得到的发动机换算性能基本一致.这表明环境压力在70 kPa以上(海拔高度3 km以下)时,对研究的发动机而言已经工作在雷诺数自模区,即环境压力的变化对试验换算性能的影响可以忽略.从而,可以利用海拔高度3 km以下的地面试验来确定研究发动机在标准大气海平面静止空气条件下的性能.

Research of Altitude Effect on Aero-Engine Ground Test Performance

The altitude effect on aero-engine ground test performance was analyzed in brief,and the advantages-disadvantages of the two methods used for the analysis of this effect were compared.A method was put forward to study the above-mentioned influence through the inlet pressure's influence on the engine performance at constant ram ratio with the help of the ATF particular advantage of pressure regulation and control.The test result of an engine shows that its corrected performances agree well with the test results when the inlet total pressure is kept in the range from 70 through 90kPa and the fan corrected rotating speed,94.5% to 96.5% at a constant ram pressure ratio of 1.6.It means that engine Reynolds Number is already higher than the critical Reynolds Number when the ambient pressure is above 70 kPa or the altitude is below 3 km.In this range,the influence of the ambient pressure change on the engine corrected performance can be neglected.Thereby,engine performance at static standard sea level atmospheric condition can be determined through engine ground test with altitude less than 3 km.