Citation

Wang HY, Coutin M, Most JM. Fire Safety J. 2002; 37(3): 259-285.

Copyright

(Copyright © 2002, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Large-eddy-simulation (LES) is performed to investigate the transport characteristics and structure of large-scale, turbulent fires on vertical surfaces under natural convection conditions. The combustion process in buoyancy-driven wall fire plumes is assumed to be diffusion controlled, permitting a mixture-fraction-based modeling approach. The three-dimensional, time-dependent Navier-Stokes equations and mixture fraction are solved with sufficient temporal and spatial resolution. The large-scale eddies are simulated directly and subgrid-scale motion is represented by Smagorinsky model. The computed, time-averaged flame height, velocity and temperature profiles are compared with experimental data, and a relatively good agreement is attained. For a given heat release, the air entrainment rate over a vertical wall fire decreases to 1/4 one of a pool fire plume. The predicted entrainment rate closely follows an adjusted entrainment rate correlation from a pool fire plume. It is observed that the flame height behind a pyrolysis region over a vertical wall is more important than that for turbulent jet fire, and also a function of the heat release raised to the nth power with n=2/5.