Flame-Spread Characteristics of Droplet-Cloud Element with Two-Droplet Interaction at High Pressure in Microgravity

Abstract

Spray combustion is widely used in gas turbines, diesel engines, jet engines, boiler and oil-fired heaters. It is indispensable for life and industry. In order to improve understanding of the flame-spread mechanism in the fuel sprays, many researchers have conducted microgravity experiments on the flame-spread of fuel-droplet arrays and droplet-cloud elements. The effect of ambient pressure on the flame-spread phenomena has also been investigated. This research involves microgravity experiments being conducted on the flame spread over droplet-cloud elements at high-pressure condition. The droplet-cloud element consists of three droplets, Droplets B, A and L. Droplets B and A are interactive droplets. Droplet L is the droplet to investigate the characteristics of flame spread from Droplet A. The results suggest that interactive combustion between Droplets B and A increases the flame-spread-limit distance from Droplet A to Droplet L at 200 kPa. The 1200 K position of the thermal layer around Droplet A also increases with the interactive combustion. This research also conducted the flame spread to Droplet L in the perpendicular direction, y-direction, to the direction from Droplet B to Droplet A, x direction. The results suggest that interactive combustion between Droplets B and A increases the y-direction flame-spread-limit distance to Droplet L more than the x-direction flame-spread-limit distance.