A modified blocked-off method for the radiation heat transfer in irregular geometries

Abstract

Radiation heat transfer is essential in high temperature industrial devices. Accurate calculation of radiative heat flux along walls of these devices is vital for their thermal design. Blocked-off method is a simple method to treat the irregular geometries by approximating physical irregular wall with step-like boundaries. When it is coupled with the finite volume method or the discrete ordinate methods, it generates non-physical oscillating radiative heat flux along the irregular boundary. To address this issue, the work proposes a modified blocked-off method. The results show that radiative heat flux along the irregular walls obtained by the modified scheme is much smoother and more accurate than that of the original scheme. The modified scheme also generates oscillating results for large optically thickness, but its fluctuations are smaller.