This work aims to investigate the effects of heat radiation and convection in the near field and far field of a spreading flame front over a horizontal fuel bed. Model calculations are made to examine different fuel preheating mechanisms that affect the fire spread. The results indicate that the convective cooling effect is important and could not be ignored. For the fuel elements in the near field, the radiation from the flame front and the combustion zone is not sufficient for fuel preheating, and the mechanism of convective heating should be considered. The convective cooling of the fuel bed has a considerable long influence range ahead of the flame front, while the influence range of convective heating is in a shorter length scale. The flame radiation on fuel preheating takes effect in the whole field. There is a sharp increase of the temperature when fuel elements get closer to the flame front in the near field due to the combined effects of three heating mechanisms. The contributions of the flame radiation, the combustion zone radiation and the convective heating to fuel preheating are of the same magnitude in the near field. The combustion cooling takes effect in the far field, while the convective cooling coefficient affects both far field and near field.

International Seminar on Fire and Explosion Hazards (9; 2019; Saint Petersburg, Russia). Proceedings of the Ninth International Seminar on Fire and Explosion Hazards [Электронный ресурс]: 21-26 April 2019, Saint Petersburg, Russia. Vol. 2 / Peter the Great St. Petersburg Polytechnic University, Autonomous Non-Profit Organization "Fire and Explosion Safety", Gefest Holding Ltd ; [edited by A. Snegirev [et al.]. — Электрон. текстовые дан. (1 файл : 98,7 Мб). — Saint Petersburg, 2019. — Загл. с титул. экрана. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Adobe Acrobat Reader 7.0. — <URL:http://elib.spbstu.ru/dl/2/k19-97.pdf>. — <URL:http://doi.org/10.18720/SPBPU/2/k19-97>.