A numerical study of combined convective and radiative heat transfer in non-reactive turbulent channel flows with several optical thicknesses: a comparison between LES and RANS

Abstract

This work presents a numerical study of turbulent channel flows with combined convective and radiative heat transfer in participating media by means of large Eddy simulation and Reynolds averaged Navier–Stokes (RANS) with k–ε model. The main purpose is to evaluate the employment of the traditional modeling (RANS without TRI) for the prediction of time-averaged parameters of turbulent non-reactive flows with convective and radiative heat transfer. All cases are investigated with Re τ = 180, Pr = 0.71 and for various optical thicknesses: τ 0 = 0.01, 0.1, 1.0, 10 and 100. In spite of the consideration of non-relevance of turbulence–radiation interactions for non-reactive turbulent flows, the results shown that for τ 0 ≥10 the employment of RANS with k–ε model led to considerable deviations for the prediction of time-averaged radiative fluxes and divergence of the radiative fluxes. For τ 0 = 100, both models also led to different results for the time-averaged convective fluxes.