Effect of Pressure on Soot Formation and Properties in Laminar RP-3 Kerosene Diffusion Flames

Obtaining quantitative experimental data on soot properties of aviation kerosene at elevated pressures is a significant concern for the surrogate fuel kinetic model of aviation kerosene. However, there are scarce studies on soot formation and properties of aviation kerosene in tractable flames at elevated pressures in literature. In this study, Chinese RP-3 aviation kerosene is used in relevant experiments and numerical simulations up to 3.5 atm to evaluate the effect of pressure on soot formation and properties. Soot morphology, nanostructure, and concentration are studied by transmission electron microscopy and laser extinction method. Then, an RP-3/PAH kinetic model containing the 5-aromatic rings (A5) growth mechanism is proposed to simulate the soot formation processes at elevated pressures. Quantitative experimental results show that pressure significantly affects the soot morphology, nanostructure parameters. The peak soot volume fractions in the RP-3 flame scale with the pressure as (Formula presented.). The numerical results show that the RP-3/PAH model can depict the trends of soot particle size and soot volume fraction with pressure. At 1.0–3.5 atm, the rates of soot growth processes increase with pressure, especially the PAHs condensation. The significantly increased soot surface growth rate may be one of the main factors for the variation of soot properties with pressure. The quantitative experimental and numerical results contribute to the understanding of the kinetic mechanism of soot formation for RP-3 kerosene at elevated pressures.