The thrust and infrared radiation(IR) characteristics in the waveband of 3~5 μm of two-dimensional(2-D) ejector nozzle were studied numerically.The flow field of the exhaust jet was calculated with commercial software.The infrared radiation characteristics were calculated with an IR analysis software (NUAA-IR) developed by our research group.The results show that spacing ratio and area ratio have different impacts on the thrust ratio and mass-flow ratio of the 2-D ejector nozzle.Spacing ratio and area ratio have greater impact on wide detected plane within a small azimuth angles.In relation to a 2-D nozzle

the integral IR intensity of a 2-D ejector nozzle can be reduced about 50%.