THE STABILITY AND VISUALIZED FLAME AND FLOW STRUCTURES OF A COMBUSTING JET IN CROSS-FLOW

The blowoff stability and flame behavior of a combusting propane gas j et issuing from a well-contoured burner perpendicularly to a cross air stream in a wind tunnel test section is studied experimentally. A cat egory of never-lift flames was found to have different stability chara cteristics and behavior from the conventionally reported liftable flam es. The stability domain of the never-lift flames covers higher cross- flow velocities and lower fuel jet velocities compared with the liftab le flames. The flame configurations in the stability domain are indent ified by characteristic modes: down-washed flame, flashing flame, deve loping flame, dual-flame, flickering flame, and pre-blowoff flame. The schlieren photographs are presented in order to discuss the effects o f the flow structures on the general behavior of the flames in each ch aracteristic mode and on the flame stability characteristics. The bise ctor of the eddy travelling avenue reasonably depicts the trajectory o f the combusting jet in cross flow. Correlations for the trajectories of cold and combusting jets in cross flow are obtained.