离散光谱分辨率对喷流红外特性FVM计算的影响

建立了辐射传递方程(RTE)的有限元体积法(FVM)计算模型,研究了离散光谱分辨率对FVM计算精度的影响,提出了离散光谱分辨率无关解的概念,并编制了相应的FORTRAN源程序,结合大气飞行发动机标准算例进行了一系列计算和比较.结果表明;在给定的红外光谱域中,随着离散光谱的分辨率的提高,计算出的方向光谱辐射强度渐渐趋向于同一个值.在航空发动机喷流2～5μm红外光谱区间中,当划分150个以上等间隔光谱微元后,FVM可以保证达到离散光谱分辨率无关解. 

Effect of discrete spectral resolution on calculation of the infrared characteristics of engine plume

Finite volume method(FVM) model and its solution procedure were established.And corresponding FORTRANprogram was developed to simulate the plume infrared characteristics,in2～5 μm,of a standard example engine that flies in atmosphere.This study focuses on the effect of the discrete spectral resolution in FVMon the infrared calculation precision.The result shows that the source directional spectral radiative intensity becomes,after absorption along a 0.88 km horizontal sea level path,gradually independent of the discrete wavelength when the discrete spectral resolution increases.When the number of discrete equal intervals of the infrared wavelength of 2～5 μm in FVMis more than150,the infrared spectral radiative intensity emitted from the plume is independent of the discrete spectral resolution.