Abstract
Combustion-generated soot remains a significant environmental and health concern, necessitating effective mitigation strategies. This study investigates the suppression of soot in acetylene diffusion flames through fuel flow oscillation, employing both experimental and numerical approaches. The effects of relative amplitude (A (out)) on soot production rates (R (soot)) and sound pressure level (SPL) were examined across a range of excitation frequencies (f from 25 to 1200 Hz), acetylene flow rates (QC2H2) , and nozzle inner diameters (D (in) from 1.05 to 6 mm). Additionally, the formation of standing acoustic waves was analyzed to reduce energy consumption. Results indicate that R (soot) is minimally influenced by QC2H2 but is predominantly controlled by the ratio A (out)/D (in). There exists an optimal f at which both R (soot) and SPL reach their minima when A (out)/D (in) ≤ 2 mm(-1), highlighting the role of combustion-acoustic coupling. Notably, the SPL increases sharply with ignition intensification. When standing waves are established within the fuel delivery tube, R (soot) can be reduced by 96.7% with a remarkably low speaker power of only 1.4 mW. These findings demonstrate a promising, energy-efficient method for soot mitigation in combustion systems through controlled acoustic oscillations.