利用数值仿真方法研究了H2O和CO2高温混合气体喷流的红外辐射特性。根据H2O和CO2两种气体的吸收特性，将红外波段划分为1.32~1.69 μm、1.56~2.27 μm、2.27~3.8 μm、3.8~8.3 μm和8.3~20 μm五个波段。建立了基于某型发动机喷嘴的尾流红外辐射特性模型，并利用此模型分别研究了H2O和CO2高温混合气体喷流在这五个波段的辐射特性分布。仿真结果表明，喷流中H2O含量越高，越有助于能量的扩散，因此喷流温度和辐射能量也越低；在高温喷流的辐射特性中，中波红外波段辐射能量最强，长波红外波段的最弱。

Infrared radiation characteristics of the high-temperature H2O and CO2 gas mixture jet flows are investigated with the numerical simulation method. The infrared band is divided into five bands (1.32-1.69 μm, 1.56-2.27 μm, 2.27-3.8 μm, 3.8-8.3 μm and 8.3-20 μm) according to the absorption features of H2O and CO2 gases. The model for describing the infrared radiation characteristics of wake flows from an engine nozzle is set up, and the radiation characteristic distributions of jet flows in the five infrared bands are numerically simulated based on this model. The results show that the more H2O content in the jet flows, the more contributions to the energy diffusion, thereby the temperature of jet flows and the quantity of radiation are lower. In addition, there is the maximum radiation quantity in the mid-wave infrared band and the minimum radiation quantity in the long wave infrared band.