Unstable flame structure adjacent to discrete wall with narrowly-ventilated air cavity

Abstract

This paper investigates the interaction between a discrete non-reactive wall with a narrow ventilated cavity and a turbulent diffusion flame. The analysis is based on both experiments and large eddy simulations (LES). Firstly, the prediction is compared with experiments on two reference configurations: a continuous wall and a discrete system. The analysis was carried out to establish the validity of models to capture the boundary-layer flame and heat exchange. Overall, the predictions are in reasonable qualitative and quantitative agreement with experimental results. The article then examines the spacing effect of inert discrete elements on flame characteristics. The analysis is conducted for a vertical and horizontal layout. The orientation and spacing of the elements affect the stability of the flow structure and fire dynamics. It produces larger or smaller flames, which affect the flame-to-element heat transfer. Correlations were developed to predict flame height and heat flux. The study's findings can aid further fundamental studies to predict and mitigate the flame spread risk over such systems with combustible elements.