Heat transfer analysis of impinging flames using field synergy principle

Abstract

The principle of field synergy well reveals the physics of fluid convection heat transfer. This study was carried out to apply the field synergy principle in a special case by conducting a theoretical and numerical analysis of jet-flame-and-wall impingement heat transfer. Numerical simulations of both premixed-flame and diffusion-lame impingement heat transfer are performed. First of all, traditional evaluation indices successfully used for field synergistic analysis of fluid convection heat transfer are adopted in an attempt to synergistically examine flame impingement heat transfer. Then, a theoretical analysis is carried out, with the results pointing out that the role of internal heat source should be taken into account. Then, a new evaluation index St considering chemical reactions as internal heat source is proposed. The theoretic results of a derivation from St to forced convection heat transfer coupling with numerical treatment of heat release shows good consistence with flame heat transfer data. It hints that for putting forward a comprehensive evaluation index for flame convection heat transfer, great care should be given to coupling the effects of both convection and internal heat source.