排气系统与尾机身一体化红外抑制器实验分析

Experimental research on infrared suppressor integrating the exhaust system with the tail part of a helicopter

利用地面模拟实验件对排气系统与尾机身一体化红外抑制器模型进行了实验研究,旨在分析引射混合与旋翼下洗对降低排气温度和目标的红外辐射特征的效果.结果表明,通过波瓣喷管引射周围空气与主流燃气掺混冷却,可以使高温燃气温度降低至少50%;利用旋翼下洗气流吹散热排气,冷却尾机身模型壁面,可以使模型壁面及尾焰在3-5μm和8-14μm的红外辐射强度分别降低39%和33%.另外,简单的增大波瓣喷管的尺寸并不能够有效提高引射流量,反而会使引射系数有所降低.

Utilizing a ground test model, an experimental diagnostie study on the infrared suppressor integrating the exhaust system with the tail part of a helicopter has been performed to investigate the effects of ambient air pumping-mixing and rotor downwash on reducing the exhaust system temperature and diminishing the target infrared signature. The result shows that the gas temperature can be reduced by 50% at least by lobed nozzle whieh injects ambient air to mix with the hot gas; and rotor downwash flow that cools the tail part of the model will eause a deerease of total infrared radiation between 3-5μm and 8-14μm equivalent to about 39% and 33%. In addition, simply enlarging the lobed nozzle is not propitious to the enhancing of the entrained flux, while it will reduce the injection coefficient.