航空活塞发动机高空台试验性能分析

为测试HS990航空活塞发动机的高空适用性，分别采用不同化油器对HS990发动机进行高空台试验。分析发动机装国产和进口化油器的性能数据，研究发动机高空熄火现象发生的原因及缸温变化对发动机高空性能的影响。结果表明：HS990发动机最大工作高度超过7km，在5km以上高度使用非增压油箱工作时，进气温度低于-18℃，HS990发动机的膜片式化油器会出现供油减少甚至停止的故障。对比装国产化油器和进口化油器时，发动机分别具有较好的高空功率特性和高空工作稳定性。适当的冷却空气量有利于降低汽缸头部温度，保证发动机稳定工作。

The Altitude Simulation Test Analysis for a Piston Aero-Engine

In order to test the altitude operability of HS990 Piston Aero-engine, homemade and imported carbu- retors are used respectively for the HS990 engine experiments in an altitude simulation test cell. Performance data of engine adopting homemade and imported carburetor are also analyzed respectively. The reason why en- gine altitude flameout phenomenon will happen is investigated and the influence of cylinder temperature on the altitude performance of engine is studied. The results show that the maximum operating height of HS990 piston engine exceeds 7km. When the altitude is above 5km and the inlet temperature is below --18~C, the existing di- aphragm carburetor will reduce or even stop fuel supplying. Comparing with imported carburetor, homemade carburetor has a better power-altitude performance, but imported carburetor has better operating stability in high altitude. Appropriate cooling air flow will be advantageous to the cylinder to decrease its operating temper- ature, and ensure the engine operating stability.