Time‐resolved soot particle growth in shock induced high pressure methane combustion

The reflected shock wave technique was used to study soot formation in highly argon‐diluted methane‐oxygen mixtures. The experiments were performed at temperatures ranging from 1700 K to 2000 K and high pressures (3000–9000 kN/m²) behind the reflected shock. Soot particles were detected and measured by the optical dispersion quotient method. Particle sizes up to 0.25 μm and particle concentrations up to 10¹⁰ particles/cm³ could be measured. The typical characteristics of soot formation and its dependence on temperature as found at lower pressures is shown. Soot formation proved to have a maximum at temperatures of approximately 1850 K and to increase almost linearly with pressure. Soot induction times were measured by monitoring the attenuation of a He‐Ne laser beam.