Evidence for the Wrinkled Continuous Laminar Wave Concept of Turbulent Burning

Several investigators have attempted to explain and evaluate turbulent burning rates by assuming the turbulent flame brush to be a zone traversed by a wrinkled continuous laminar flame front. Others have argued that the brush consists of a distributed reaction zone characterized by turbulent energy transport and diffusion of active species. A third point of view is that of visualizing the brush as a region containing disconnected flamelets of varying chemical composition. The purpose of the present paper is to state the case for the wrinkled wave concept and to place limits on the regime of its applicability. Experiments indicate that the distributed reaction zone model applies to conditions of incomplete burning within the flame brush. It is suggested that the transition from wrinkled wave to distributed reaction zone corresponds to the breakdown of full turbulent flames through the incidence of "holes." New photometric evidence is presented.