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Investigation of Dump Combustors with Flame Holders.

Abstract : An experimental investigation was conducted on the addition of flameholders to the inlet duct of a 5 inch D dump combustor in an attempt to reduce combustor length. Basic flameholder configurations, percentage blockage, leading edge bluntness, and trailing edge contours were varied to characterize the significant features of flameholders. A parametric study was then conducted around the two best flameholder configurations in which combustor length-to-diameter ratio (L/D), characteristic length, inlet temperature, and chamber pressure were varied. Combustion efficiency and combustor pressure losses were determined from each of these runs and compared to previous results for the basic dump combustor. Results are presented which show a marked difference in performance with small changes in trailing edge contour. Increases of up to 30 points in combustion efficiency were obtained when the best flameholder was added to the basic dump combustor with a L/D = 3.