模化比对直升机用红外抑制器红外辐射特性的影响

对波瓣喷管-弯曲混合管构成的直升机用红外抑制器壁面和尾焰的红外辐射特性进行了一系列的数值研究,旨在将三维流场数值计算、壁温计算与红外辐射计算结合起来综合分析抑制器红外辐射特性,与相关实验数据的对比验证表明计算结果与实验结果仅相差15%左右,且红外辐射强度空间分布规律一致;通过对不同缩比模型的数值计算,揭示了模化比对壁面及尾焰的红外辐射特性的影响规律:(1)几何相似的红外抑制器在主流入口速度、温度相同时,壁面红外辐射强度与几何模化比的2次方成正比;(2)尾焰红外辐射强度与几何模化比的2.32次方成正比.

Effect of scale factor on infrared radiation characteristics of helicopter infrared radiation suppressor

A research on the infrared radiation characteristics for the helicopter infrared radiation suppressor consisted of lobed nozzle and curved mixing duct is performed basing on numerical calculation.In the computation,3-D flow field computation and wall temperature computation and infrared radiation computation are combined to investigate the infrared radiation characteristics of the suppressor.Compared with the experimental data,it is indicated that the relative error between the computational and experimental results is about 15%.Spatial distribution of infrared radiation intensity has the same law as that from experiments.And a series of computations on different scale factor model are conducted to obtain the effect of model scale to the wall and plume radiations.The results indicated that the infrared radiation intensity of wall is proportional to power 2 of scale factor and the infrared radiation intensity of exhaust flume is proportional to power 2.32 of scale factor on the case of the velocity,temperature and pressure of the primary flow being keeped the same for different scaled model.