Original Articles: 2014 Vol: 6 Issue: 6
Numerical Simulation of smoke movement in vertical shafts during high-rise fires using a modified network model
Abstract
A simplified, two-layer zone coupled with network model to quantify the smoke movement during high-rise fires is presented in this paper. The main governing equations, the conservations of mass and energy, and the sub models including the convective heat transfer, radiative heat transfer and fluid mechanics, are considered in the model. The advantage of the model is the consideration of heat transfer due to the importance of temperature distributions in the vertical shaft, and the buoyancy-induced flow and the resulting driving force are strong referred to stack effects. The model is aimed at managing the smoke movement for a successful fire protection plan and improving the occupant safety in the event of fire. The generated results suggest that enlarging the vent size on top of the elevator shaft, pressurizing the floors except the fire floor and reducing the gaps around elevators can raise the location of neutral pressure plane (NPP) and create a safe environment in the upper flows. To a certain degree, the location of NPP will be raised above the total height of structure, thus the smoke will be kept inside and exhausted out of the elevator shaft.