红外抑制器模型出口温度的实验

Experimental investigation of exit temperatures of a infrared suppressor model

利用地面模拟试验件实验研究了气流参数对直升机发动机喷管出口温度的影响。实验中主喷管气流温度610℃，压力为常压，下洗气流温度为常温，速度范围为4．4～11m／s。结果表明，模型出口排气温度随着主喷管流量增加而线性增加，引射系数随着下洗气流速度增加而减小，出口排气温度随下洗气流增加时有一个峰值，增加下洗气流速度有助于降低外套壁温。实验发现外套出口和混合管之间夹层存在气流倒流现象，倒流平均速度随着主喷管流量和下洗气流速度增加而增加。

An experiment was conducted to study the influences of airflow parameters on exit temperatures of an infrared suppressor model. The temperature of the main flow was about 610℃ and the pressure of the main flow was atmospheric pressure. The downwash flow velocity ranged from 4. 4 to 11m/s. The temperature of downwash flow was atmospheric temperature. The results show that, the exhaust flow temperature grows linearly with the increase of the main nozzle flux. The entrainment coefficient decreases with the increase of the downwash flow. With the increase of the downwash flow velocity, the exhaust temperature has a peak value the exhausting duct temperature decreases with the increase of the downwash flow velocity. The averaged gas velocity of flowing backward between the exhausting duct and the mixture tube increases with the rise of the main nozzle flux and the downwash flow velocity.