Flame structure and stabilizationof lean-premixed sprays in a counterflowwith low-volatility fuel

摘要

An experimental study was performed on the combustion of lean-premixed spays in a counterflow. N-Decane was used as a liquid fuel with low volatility. The flame structure and stabilization were discussedbased on the flame-spread mechanism of a droplet array with a low-volatility fuel. The spray flame consistedof a blue region and a yellow luminous region. The flame spread among droplets and group-flameformation through the droplet interaction were observed on the premixed spray side, while envelope flameswere also observed on the opposing airflow side. The blue-flame region consisted of premixed flames propagatingin the mixture layer around each droplet, the envelope diffusion flames around each droplet, thelower parts of the group diffusion flame surrounding each droplet cluster, and the envelope flame arounddroplets passing through the group flame. The flame was stabilized within a specific range of the meandroplet diameter via a balance between the droplet velocity and the flame-spread rate of the premixedspray.