Experimental Studies of Flame Spread

North Carolina State University, Raleigh NC

Investigators

Abstract

This is an experimental study of the structure of a leading-edge partially premixed flame and a trailing diffusion flame in a layered methane-air system. Conditions for the existence of triple flames at the leading edge of speeding flames are investigated; these have been considered as the anchoring mechanism for lifted flames as well as being responsible for the spread of the edges of diffusion flames into gaseous mixing layers. This study aims to illuminate the detailed structure of the leading edge in a simple layered system using a variety of diagnostic techniques including CH and OH fluorescence and Rayleigh scattering, and to investigate the response of the leading-edge structure to changes in such parameters as fuel-stream and air-stream velocities, fuel composition, and flow orientation.