Laminar Non-Premixed Flames

Almost all practical combustion devices use non-premixed flame. Chapter 7 offers considerable coverage on laminar non-premixed flame. It provides a discussion on physical observation along with simplified analysis related to laminar non-premixed flame. Subsequently, the chapter deals with conserved scalar concept and its requirement for diffusion flames. The discussion is related to mixture fraction, absolute energy and their conservation equations. Two typical flame structures – Burke-Schumann and counter-flow flames – are then analysed. The need of state relations is also considered in connection with the Burke-Schumann flame. The effect of detailed chemistry in analysis is discussed in the context of counter-flow flame. A discussion on partially premixed flames and their structure is covered. Soot generation is a common feature of non-premixed flames, and it is discussed subsequently. Finally, the effect of exit velocity on jet flame structure is discussed.