Optimization of the MSMGWB models used to predict remote infrared signals of jet engine in various spectral intervals

Further improvements are reported for an optimization method that was used in previous work to determine the best combination of Gauss quadrature schemes and wavenumber subinterval division results for the multi-scale multi-group wide-band k-distribution (MSMGWB) model, which is used in calculation of remote infrared signals of hot combustion gases from hydrocarbon fuels and gray walls in the 3–5 µm spectral interval. In addition, the application range of the MSMGWB model was extended to the 8–14 µm, 7.7–9.7 µm, 3.7–4.8 µm, and 2–2.5 µm spectral intervals. Compared with previous works, the new optimization procedure considered a broader range of thermodynamic state parameter combinations of the combustion gas and the atmosphere. The optimization effect was evaluated further via prediction of remote sensing thermal images in various spectral intervals for solid structures and hot jet of an aero-engine’s supersonic exhaust system. Furthermore, an optimized MSMGWB model that considers the spectral response characteristics of infrared detectors has been established and evaluated.