针对现有的宽带k分布模型不适合温度和参与性组分比例剧烈变化的气体的辐射特性计算的问题, 建立了多尺度多线组宽带k分布模型(MSMGWB), 并针对舰用燃气轮机排气系统远程辐射特性计算面临的高温燃气与环境空气热力学参数, 对MSMGWB模型的光谱吸收系数分组进行了优化。一系列一维气体辐射传输算例的计算结果表明: 当高温燃气与低温空气的温度和水蒸气、二氧化碳、一氧化碳摩尔比差别巨大时, 多尺度多线组宽带k分布模型对3~5 ?滋m波段气体辐射传输特性的预测精度远高于原始宽带k分布模型和窄带模型, 并且与灰体固壁保持了很好的兼容性。最后, 对不同相对风速下舰用燃气轮机引射排气系统的流场、固体温度场及其近、远距离红外成像进行了数值计算, 结果表明: 气体重力和燃气中的一氧化碳对其3~5 ?滋m波段红外成像的影响不能忽略。

To solve the problem that existing k distribution model is not suitable for calculating the radiation characteristics of gases with drastic changes in temperature and the proportion of participating components, a multiscale multigroup wide band k-distribution model(MSMGWB) was established. The spectral absorption coefficient grouping of MSMGWB model was optimized according to the thermodynamic parameters of high temperature gas and ambient air for the calculation of remote sensing thermal image of exhaust system of marine turbine engine. The calculation results of a series of one-dimensional gas radiation transmission examples show that when the temperature of high temperature gas and low temperature air and the mole ratio of water vapor, carbon dioxide and carbon monoxide are greatly different, the prediction accuracy of the multiscale multigroup wide band k-distribution model for the 3-5 micron wave band gas radiation transmission characteristics is much higher than that of the original wide band k-distribution model and narrow band model, and it maintains good compatibility with the solid wall. Finally, the flow field, solid temperature field and close-range and long-range infrared images of exhaust system of marine turbine engine under different relative wind speeds were studied. The results show that the effects of gas gravity and carbon monoxide on infrared images under the 3-5 ?滋m band cannot be ignored.