Comparison of Fire Induced and Heat Driven Flows in Vertical Shafts

The Fire Dynamics Simulator (FDS) code is used to investigate fire induced and heat driven flows in typical shafts. Results of the fire induced and the heat driven flows in a shaft show good agreements with the experimental data. Then, flows induced by a fire and by a heater in four different shafts are investigated. The simulation results give details of the flow fields from the initial to the fully developed stages. Although the fire induced flow pattern is similar to that of the heat driven flow, the former is much stronger with more vortices in the flow field. The temperature of the fire induced flow is also much higher than that of the heat driven flow. Furthermore, numerical results show that the different openings of the shafts have remarkable effects on the flow patterns in the shafts.