Effect of inlet turbulence on the large eddy simulation of fire plume turbulent characteristics near the ground

Abstract

Fire hazard has become a severe threat for ecosystem and urban city. Accurate modelling of fire behaviour and pollutant transport in the atmospheric boundary layer is important for fire risk management. The effect of using turbulent inflow model on simulating fire plume development remains unclear. To understand whether it is important or not for large eddy simulations of fire plume, we performed numerical experiments of fire combustions under uniform and turbulent inflows, and considered two wind velocities, representing weak and moderate conditions respectively. Results show that the assumption of uniform flow does not have significant effect on the mean temperature and velocity fields for weak wind but obvious effect for moderate wind. Turbulent fluctuations of the fire flame indicates that fire plume development modelling is more influenced by the background wind turbulence under relatively larger velocity.