Effects of ethanol addition on soot formation in co-flow Jet A diffusion flame

To investigate the characteristics of soot formation in blends of Jet A and ethanol, a coaxial laminar co-flow diffusion flame system was constructed. The Laser-Induced Fluorescence (LIF) and Laser-Induced Incandescence (LII) techniques were employed to assess the distributions of Polycyclic Aromatic Hydrocarbons (PAH) and Soot Volume Fraction (SVF) in Jet A with ethanol volume blending ratios ranging from 0 % to 80 %. It was observed that the flame height, luminescence, PAH concentrations, and SVF all decreased as the ethanol blending ratio increased. Similarly, the peak mole fraction of soot precursors diminished with an increase in ethanol blending ratio. The pathways of A1 formation were analyzed using a zero -dimensional homogeneous model. Rate of Production (ROP) analysis indicated that ethanol had a minimal impact on the A1 formation route, which primarily stems from styrene. Ethanol's dilution effect was identified as the predominant factor. The presence of ethanol resulted in the dilution of propylbenzene in the fuel blend, leading to decreased formation of styrene and benzene. Consequently, the SVF was lowered.