Quantitative soot volume fraction measurements were conducted in a counterflow non-premixed flame configuration using ethylene/nitrogen as the fuel stream, oxygen/nitrogen as the oxidizer stream, and a pressure range of 1–8 atm. The laser-induced incandescence technique, calibrated using the light extinction method, was used to measure the soot volume fraction distributions. The variations of soot formation along the centerline of the counterflow flame with pressure were compared by keeping the density-weighted strain rate constant. Maintaining a constant density-weighted strain rate allows the overall flame thickness, as well as the reactant mass fluxes entering the flame, to remain unchanged for all pressures. As such, the effect of pressure on soot chemistry can be isolated from the effect of convective-diffusive transport. Based on the measured soot volume profiles, the soot layer thickness variation with pressure was determined. It was found that when keeping the density-weighted strain rate constant, the soot layer thickness remains similar over the pressure range investigated. However, the soot layer thickness was seen to decrease with increasing pressure when holding the strain rate fixed. In addition, the effects of fuel mole fraction and oxygen mole fraction on soot formation were investigated. Furthermore, the pressure scaling factors of soot formation under varying mixture conditions were deduced from experimental measurements. A literature gas-phase reaction mechanism including polycyclic aromatic hydrocarbon (PAH) chemistry up to pyrene was also used to simulate the experimental counterflow flames. The pressure effect on PAH formation was presented and discussed.

在逆流非预混火焰配置中，使用乙烯/氮气作为燃料流，氧气/氮气作为氧化剂流，压力范围为1-8个大气压，对烟灰体积分数进行了定量测量。使用消光方法校准的激光诱导白炽技术用于测量烟灰体积分数分布。通过保持密度加权应变率恒定，比较了沿逆流火焰中心线的烟灰形成随压力的变化。保持恒定的密度加权应变率可使整个火焰厚度以及进入火焰的反应物质量通量在所有压力下均保持不变。这样，可以将压力对烟chemistry化学的影响与对流-扩散传输的影响分开。基于测得的烟灰体积分布，确定烟灰层厚度随压力的变化。发现当保持密度加权应变率恒定时，烟灰层厚度在所研究的压力范围内保持相似。但是，当保持固定的应变速率时，烟灰层厚度会随着压力的增加而减小。另外，研究了燃料摩尔分数和氧气摩尔分数对烟灰形成的影响。此外，从实验测量中推导出在变化的混合条件下烟灰形成的压力比例因子。文献中涉及的气相反应机理包括直至pyr的多环芳烃（PAH）化学反应也用于模拟实验逆流火焰。