二元收扩喷管设计参数对红外特征影响的数值研究

采用正交试验设计方法进行排气系统红外辐射(IR)特征数值模拟算例的设计,研究了二元收扩喷管(2D-CD)喉部宽高比、喉部型面半径比、收敛半角和扩张半角等参数对排气系统红外辐射特征的影响,并且开展了参数对排气系统红外辐射特征影响灵敏度的分析。结果表明:扩张半角是影响二元排气系统红外辐射特征空间范围最宽的参数,收敛半角主要影响尾向10°~30°范围的红外辐射特征,喉部宽高比主要影响正尾向0°和侧向90°的红外辐射特征,喉部型面半径比对红外辐射特征的影响较小;二元排气系统不同方向上红外辐射特征的最主要影响参数不同,正尾向0°方向上的最主要影响参数是喉部宽高比,侧向90°方向上的最主要影响参数按影响程度大小排序依次为扩张半角、喉部宽高比。

Numerical investigation of influence of two-dimensional convergent and divergent nozzle's design parameters on infrared characteristics

The computational cases of infrared radiation (IR) characteristics of exhaust system were designed using the orthogonal experiment design method. The influences of geometric parameters on IR characteristics of two-dimensional exhaust system were investigated. The geometric parameters studied included throat width to height ratio, throat radius ratio, convergent half angle and divergent half angle of two-dimensional convergent and divergent (2D-CD) nozzle. The sensitivity analysis of the four geometric parameters was performed. Results showed that the divergent half angle was the widest parameter that influenced the spatial range of IR characteristics of 2D exhaust system. The convergent half angle mainly influenced IR characteristics within the range of 10°-30° in the tail direction. The throat width to height ratio mainly influenced the IR characteristics of 0° in the positive tail direction and 90° in the lateral direction. The throat radius ratio had little influence on the IR characteristics. The main influence parameters of IR characteristics in different directions of 2D exhaust system were different. The most important influence parameter in the direction of 0° was throat width to height ratio. The most important influence parameters in the direction of 90° were divergent half angle and throat width to height ratio.