Calculation of radiative heat flux on irregular boundaries in participating media

Radiative heat flux at wall boundaries is important for its thermal design. Numerical methods based on structured grids are becoming trendy due to their simplicity and efficiency. Existing radiative transfer equation solvers produce oscillating radiative heat flux at the irregular boundary if they are based on structured grids. Reverse Monte Carlo method and analytical discrete ordinates method are adopted to calculate the radiative heat flux at complex boundaries. The results show that the reverse Monte Carlo method can generate a smooth radiative heat flux profile and it is smoother with larger energy bundles. The results from the analytical discrete ordinates method show that the fluctuations are due to the ray effect. For the total or the mean radiative heat flux, the results from the analytical discrete ordinates method are very close to those from the reverse Monte Carlo method.