Premixed turbulent flames at engine conditions: profiles of ch band emission across the flame zone determining local values of burning rate

摘要

In the flamelet regime, the speed of flames in turbulent mixtures is essentially determined by the wrinkling of the flame surface. A quantity measuring this increase of surface area of the flame is the flame surface density. This study introduces an analysis to derive the flame surface density from light emission measurements and presents measured profiles across flames zones of a two-dimensional combustion process under engine conditions. The pofiles determine the local turbulent flame speed and permit a statistical definition of the turbulent flame thickness. The variations of time of observation, of turbulence intensity and laminar flame speed provide substantial information to improve understanding of turbulent premixed combustion under engine conditions and to analyze detailed models.