Jian Cai
University of Wyoming, Laramie, WY 82071
Xinyu Zhao
University of Connecticut, Storrs, CT, 06268, USA
Michael F. Modest
School of Engineering, University of California, Merced, California, USA, 95343
Daniel C. Haworth
Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
Radiation is an important heat transfer mode in pulverized coal flames. Its modeling is challenged by the treatment of the multiphase mixture and the non-gray effects of participating gases and particles. In this work, the k-distribution methods that can successfully account for gas non-gray effects are applied to a pulverized coal ignition flame, in which the carrier gas is modeled by Eulerian equations while the particles are tracked individually in a Lagrangian framework. Bulk radiative properties from the dispersed particles are assembled to the full-spectrum k-distributions of the carrier gas. The Radiative Transfer Equations are solved by the P1 approximation. Radiative heat losses are fed back to the energy equations of both the carrier gas and the dispersed particles. It is found that radiation causes a 500 K temperature difference. Radiative absorption predicted by the k-distribution methods contributes to a 100 K temperature increase. The absorption is nongray therefore cannot to be captured by gray models.