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.