Approaches to Modeling Bed Drag in Pine Forest Litter for Wildland Fire Applications

Abstract Modeling flow in vegetative fuel beds is a key component any detailed physics-based tool for simulating wildland fire dynamics. Current approaches drag modeling, particularly those employed multiphase computational fluid dynamics (CFD) models, tend to take relatively simple form and have been applied wide range of structures. The suitability these has not rigorously tested conditions which may be encountered context. Here, we focus on Pinus rigida needle litter undertake two-part study quantify the evaluate capabilities large eddy simulation CFD model, NIST Fire Dynamics Simulator. In first part, bed was measured wind tunnel under conditions. results were fit Forchheimer permeability quantified. A traditional approach formulation compared parameterized equation found over-predict by factor 1.2–2.5. second development velocity profile above within discrete layer measured. Using obtained part study, model able replicate qualitatively consistent development. Within bed, appeared under-predict magnitudes, result unresolved pore-scale