In-Situ Observation of the Soot Deposition Process on a Solid Wall with a Diffusion Flame along the Wall

Abstract

Experiments at the Japan Microgravity Center (JAMIC) have investigated the interaction between diffusion flames and solid surfaces placed near flames. The fuel for the flames was C₂H₄ and the surrounding oxygen concentration 35%, with surrounding air temperatures of T_a=300 and 600K. The effects of these parameters on soot distribution in diffusion flames and soot deposition on solid walls were studied. Direct images of the whole flame and shadow images of the flame with back light were recorded and used to calculate the soot volume fraction by the Abel transformation method. Results show that at the higher surrounding air temperature the soot particle distribution region is closer to the wall and results in more deposition. Numerical simulation was also performed to determine the motion of soot particles in the flames and the soot deposition characteristics. The results are in good agreement with the observed soot behavior in microgravity.