Experimental research on the burning behavior of dragon juniper tree

Abstract

AbstractTree crown fire is one of the extreme fire behaviors in the wildland‐urban interface. This paper presents an experimental study on the burning behaviors of single and triple dragon juniper trees. The mass loss, flame height, plume temperature, radiation, and fire interaction are measured. It is found that the foliage moisture content and flame mergence dominate the mass consumed percentage (defined as the ratio of the total mass loss to initially total mass), while the tree crown height and flame mergence determine the flame height. The peak mass loss rate is mainly affected by the moisture content and tree species. For triple tree fires, the peak mass loss rate is also affected by the spacing due to the coupled effects of heat feedback enhancement and air entrainment restriction. Results also show that the flame height significantly increases as the spacing decreases. The spacing holds a significant effect on the fire plume temperature distribution and thermal radiation field. Empirical correlations are also developed for the flame height, radial temperature, and radiant heat flux distribution based on physical interpretation of the tree burning behaviors.