COMPUTATIONAL FLUID DYNAMICS SIMULATION OF FIRE-INDUCED AIR FLOW IN A LARGE SPACE BUILDING: KEY POINTS TO NOTE

摘要

Fire-induced air flow in a large span building by computational fluid dynamics (CFD) will be discussed in this paper. The CFD model is based on Reynolds Averaging Navier-Stokes (RANS) equations with k-e based turbulence model for predicting velocity, pressure and temperature distribution. This technique is commonly used in practical design for smoke management system. The fire is taken as a volumetric heat source and buoyancy effects are included in equations for the vertical momentum and turbulent parameters. Several key points to note in the simulation will be discussed. These are: 1. Relaxation factor and convergence criteria. 2. False diffusion. 3. Sudden changes in flow parameters across the heat source. A large terminal hall with 1 MW fire is taken as an example to discuss the above points. The fire scenarios in a region of interest will be assessed by CFD.