Aerial suppression penetrating an axially symmetric and upright buoyant wildfire plume

Abstract

An analysis was conducted on when aerial suppression through direct attack using a helicopter could be ineffective due to a high heat release rate of the wildfire. The analysis consisted of a numerical estimate and where the results were compared with existing operational thresholds on aerial wildfire suppression. It was found that up to a heat release rate of 10000 kW, practically all droplet paths effectively penetrated the plume region. At heat release rates of 12500 and 23000 kW, only the path at an angle to the centreline effectively penetrated the plume region. The calculated results of the analysis were compared with suppression thresholds and found to correspond well in the vertical trajectory case. The findings of the paper could serve as starting point for the development of decision support for aerial wildfire suppression.