Infrared radiation characteristics of turbulent gas jets based on improved SGS-TRI model

To address the issue of low prediction accuracy of gas jet Sub-Grid Scale Turbulence-Radiation Interaction (SGS-TRI) properties with the existing modeling methods, a correlation fluctuation term that accounts for the interaction between radiation-participating components and temperature into the sublattice Snegirev relationship is introduced. Simultaneously, a new and more user-friendly model for complex projects is established. The algorithm solving the dynamic sub-grid model coefficients facilitates the calculation of the dynamic Smagorinsky model and temperature variance model coefficients. The validity of this algorithm is confirmed through Direct Numerical Simulations (DNS) of isotropic turbulence and high-temperature air jet flow characteristic test data. Furthermore, considering the detection distance, the TRI properties and SGS-TRI properties of the 3-5 μm band infrared signal of the gas jet from an axisymmetric exhaust system are calculated and analyzed by utilizing the multi-scale multi-group wide-band k-distribution model. The properties of the multi-line group wide band model elucidate the formation mechanism of the observed phenomena.