Investigation of liquid fuel combustion in a cross-flow burner

A rotary swirl burner was employed for liquid fuel spray combustion in a cross-flow stream of air. The effect of fuel spray orientation on mixing dynamics with the swirled air was investigated for different nozzle angles, including -45 degrees, 0 degrees, and 45 degrees, respectively, with a variable portion of the air (from 0 to 100 per cent) allowed to flow aligned with the spray without swirl. The effect of swirl on CO and NO, emissions was found to be dominated by the competitive influences of improved mixing and increased kinetic rates. For cross injector alignment with air, NO, emissions were reduced by increasing the co-current air flow due to the improved premixing effect, while for inclined alignment its emissions exhibited a reduction by supplying enough air to the spray lee side. High swirl intensity (swirl number up to 12) and co-current/ cross-flow combination produce a reduction in the unburned hydrocarbons. The enhancement in flame radiation output with swirl was pronounced by an increase to 1.9 times the output without swirl. Inserting a porous medium at the burner exit, increased the enhancement to 4.18 times and promoted droplet evaporation. Enlarging the recirculation zone beneath the fuel injector to a certain extent improved mixing and combustion efficiency.