The Effect of the Fuel Packing Ratio on Convective Heating and Cooling of Excelsior Particles

Abstract: The fuel packing ratio (?) is one of the major parameters significantly affecting the Rate of Spread (RoS) of the fire, but the underlying physics and heat transfer mechanisms have yet to be fully investigated. This research studies the effect of betha on convective heating and cooling during the burning of excelsior particles. The Large Eddy Simulation (LES) method is used to solve the Navier-Stokes equations using the Fire Dynamics Simulator (FDS), an open-source computational fluid dynamics (CFD) model of fire-driven fluid flow. The fuel packing ratio (?), defined as the ratio of mass per unit volume divided by the material density, was varied from 0.01 to 0.04 to investigate its effect on heat transfer, the rate of spread of fire, and flame dynamics during the burning of excelsior particles. The results revealed that increasing betha reduces internal convective cooling and internal radiative heating, which in turn causes a reduction in the fire RoS. Keywords: Fire Dynamics Simulator, Large Eddy Simulation, propagating fire, Convective heat transfer, Fuel packing ratio