航空发动机在高空台上的H_0/Ma_0试验分析

Analysis of H=0 & Ma=0 test for aero-ngine at ATF

分析了发动机高空台H0／Ma0试验时，高空舱压力与标准大气压力不一致的产生原因，以及由于发动机排气引射作用与高空舱内冷却流动造成的环境压力低于标准大气海平面静止空气压力对发动机H0／Ma0试验结果的影响机理。在此基础上，提出了环境压力差异对发动机H0／Ma0试验结果影响的研究方案，并用两型发动机在不同试车台上进行了H0／Ma0试验与研究性试验。结果表明，70kPa压力环境、0．99～1．02冲压比的高空台H0／Ma0试验的换算结果，与标准大气海平面静止条件下的试验结果基本一致。

H=0 km ＆ Ma=0 test was conducted for aero-engine at altitude simulated test facility （ATF）. The reasons for the difference between altitude cell pressure and standard atmospheric pressure were analyzed. Moreover,the effects on the engine test of H=0 km ＆ Ma=0 at a pressure difference between altitude cell and international standard atmosphere （ISA） sea level static（SLS）, caused by exhaust gas ejection and cooling-air flow in altitude cell,were also studied. A scheme was thus put forward for the influence of ambient pressure change on the engine test results of H=0 km ＆ Ma=0. Furthermore,several research tests were conducted in two or three test beds of H=0 km＆ Ma=0 using a turbojet engine and a turbofan engine. The test results show that,corrected results for engine test of H=0 km Ma=0 at ATF, when ambient pressure is about 70 kPa and ram ratio is between 0. 99 to 1.02,are consistent with those under standard atmosphere, sea level static.