An atmospheric transmissivity weighted MSWB model used to calculate TRI characteristics for remote infrared signals of jet engine exhaust systems

To deal with strong thermodynamic state parameter inhomogeneities along radiation transfer paths encountered in calculation of remote infrared signal of hydrocarbon fuel combustion gas jet, an atmospheric transmissivity weighted multi-species wide band k-distribution model (ATWMSWB) was established. Results of 1D case set indicate that the optimized ATWMSWB model has higher accuracy and a fraction of computational cost for remote infrared signal calculations of uniform and non-uniform combustion gases and gray walls at typical atmospheric infrared window wide bands, compared with improved statistical narrow band model and narrow band k-distribution model. Calculation accuracy and efficiency of ATWMSWB model was further validated in a 3D case for turbulence-radiation interaction (TRI) calculation of remote infrared signal from a jet engine exhaust system and its plume, based on instantaneous flow fields obtained by large-eddy simulation (LES). The calculation parameter setting for exhaust system TRI characteristic calculation with and without influences of emitted and reflected radiations of wall was also discussed.