涡扇发动机吞雹试验

Hailstone ingestion test of turbofan engine

为研究某型涡扇发动机吞雹能力,按照CCAR-33R2标准33.78(a)条开展了整机吞雹试验方法研究及验证。梳理了试验流程,确定了试验条件,对发动机、试车台等进行了分析,开展了防护装置、摄影装置、投射装置设计,并对冰雹的制作方法进行了研究。通过投射装置实现了冰雹向发动机的投射,同时设计了试验前的校靶试验和空炮试验,通过校靶试验保证了投射的速度和准确性,通过空炮试验测试了投射装置对发动机进气的影响,又通过高速摄影验证了冰雹投射的速度和撞击位置的准确性。发动机吞入冰雹过程中推力出现短时减小,随后恢复了稳定工作,吞雹后发动机排气温度下降约2%~3%,转差变化约-0.6%~0.2%,推力下降约0.1%~1.6%;其余参数无明显变化,通过低压测点时域信号采集了风扇部分的冲击响应;试验后分解检查5片风扇叶片进气边变形,未出现掉块情况,未发现可能危及飞行安全的结构损坏,验证了某型涡扇发动机的吞雹适航符合性。

According to the CCAR-33R2 standard 33.78(a),a test method of the engine hailstone in‐gestion was studied and verified to investigate the hailstone ingestion capability of one turbofan engine.The test process was arranged;the test conditions were determined;the engine and test bench were an‐alyzed;the protection,photography,and projection devices were designed;and the producing meth‐od of hailstone was studied.The hailstone was projected to the engine by the projection device.At the same time,a target calibration test and an air gun test were designed before the actual test.The target calibration test ensured the speed and accuracy of the projection,while the air gun test tested the influ‐ence of the projection device on the engine intake.Furthermore,a high-speed photography test was conducted to verify the speed and impact accuracy of the hailstone.The engine thrust decreased for a short time during the process of hailstone ingestion and then resumed stable operation.After hailstone ingestion,the exhaust temperature of the engine decreased by about 2%~3%,the rotor difference changed by about-0.6%~0.2%,the thrust decreased by about 0.1%~1.6%,and other parameters did not have significant change.The impact response of the fan was collected through the time-domain sig‐nal of the low-pressure measuring point.After disassembling the engine,the deformation of the intake edge of 5 fan blades was checked,no block falling occurred,and no structural damage that may endan‐ger flight safety was found,which verified the airworthiness conformance of the turbofan engine for hailstone ingestion.