Effects of varying Smagorinsky constant on simulating post-flashover fires

Abstract

Air flow post-flashover room fire is weakly compressible. In this paper, Navier–Stokes equations in an appropriate form will be applied to simulate such motion. Large eddy simulation (LES) is used with the Smagorinsky sub-grid scale model. A pool fire was described by the combustion model based on simple and fast chemical reaction. Three-dimensional simulations were carried out by using different values of Smagorinsky sub-grid scale constant.

Predicted results on air temperatures and radiative heat fluxes were compared with the experimental values. Results illustrated that the value of the Smagorinsky constant would affect the simulations for strong buoyant plume. Value of the Smagorinsky constant from 0.20 to 0.21 appears to be reasonable in simulating flashover with a filter width of 0.1 m.

Keywords:

• Fire
• Flashover
• Large eddy simulation
• Smagorinsky sub-grid scale constant

Notes

^§ Postal address: Department of Building Services Engineering, The Hong Kong Polytechnic University, Hunghom, Kowloon, Hong Kong, People's Republic of China.

Additional information

Notes on contributors

Wan-Ki Chow

§ § Postal address: Department of Building Services Engineering, The Hong Kong Polytechnic University, Hunghom, Kowloon, Hong Kong, People's Republic of China.