喷口修形对二元喷管红外特征影响的数值研究

为降低排气系统的红外特征,以轴对称喷管为基准,设计了一种出口宽高比为4∶1的二元喷管;并对二元喷管出口型面进行不同尾缘修形。在商业软件中计算了二元喷管的温度场、速度场、压力场和组分浓度场的分布,采用自主开发的红外软件NUAA-IRSE,用反向蒙特卡罗法计算各喷管的红外辐射特征;并与基准轴对称喷管的计算结果进行对比。计算结果表明:二元喷管及对其尾缘修形后,遮挡了部分排气系统内部的高温部件,强化了尾喷流的掺混,在大部分探测方向上抑制了排气系统的红外特征;在喷管推力系数下降小于2%前提下,尾喷流红外最大降低36%,高温壁面红外最大降低28%。

Numercial Sumlation of IR for 2-D Nozzlewith Different Trailing Edge Modification

In order to reduce the infrared radiation of exhaust,based on the axisymmetric nozzle,a kind of two-dimensional nozzle with different trailing edge modification was designed to suppress the infrared radiation characteristics, Based on the distribution of temperatute , pressure and species mass fraction of the two-dimensional nozzle obtained from CFD results, the infrared radiation characteristics of two-dimensional nozzle was calculated with reverse Monte-Carlo method,then analyzed and compared with axisymmetric nozzle. The results show that, The two-dimensional nozzles with trailing edge modification are capable of shielding the high temperature elements inside the exhaust system effectively, the infrared radiation characteristics of the exhaust plume and wall is further suppressed by 36% and 28% respectively.