Conjugate conduction-radiation heat transfer of non-gray gases in a 2D combustion chamber using ray tracing method and SLW correlated model

The present study examines combined conduction-radiation heat transfer in non-gray gases within a two-dimensional rectangular domain, representing a section of a combustion chamber. The participating gases considered are 10 % C O 2 / N 2 , 20 % H 2 O / N 2 and their corresponding mixture, whereas N 2 is treated as non-participating. A correlated SLW model is developed to evaluate the Planck-mean absorption coefficients by summing the products of discrete gray absorption coefficients and their associated weights. The radiative properties of the non-gray gases are obtained over their absorption spectral bands using data from HITEMP2010, while thermal conductivities are computed using the Sutherland relation. An exact semi-analytical formulation based on ray tracing, Bickley-Naylor functions, and Gauss quadrature is employed to solve the radiative transfer equation (RTE) using Planck-mean absorption coefficients. The energy equation is discretised using a finite-difference approach with a Crank-Nicolson scheme. The effects of gas thermal properties, gas temperature, the number of discrete gray gases, gas species, and mixture ratios on thermal quantities are analysed in detail. Numerical simulations of dimensionless conduction-radiation temperature and total heat flux are presented. • Radiative and conductive properties of non-gray gases, such as carbon dioxide C O 2 , water vapor H 2 O and their mixture are evaluated using the SLW correlated model, with updated experimental coefficients and the Sutherland relation, respectively. • The coupled conduction-radiation problem, accounting for non-gray gas thermal properties, is solved in a two-dimensional rectangular combustion-chamber geometry. • Temperature distribution and total heat flux are simultaneously obtained using the ray-tracing and finite-difference methods. • The influence of the number of discrete gray gases, chemical ratio, the reference and gas temperatures on conduction-radiation heat transfer is analysed.