Simulation Research on Effects of Ambient Pressure on Plug-Holing Phenomenon in Tunnel Fires with a Shaft

This paper studied the effects of ambient pressure on plug-holing phenomenon in tunnel fires with a shaft by Fire Dynamics Simulator. The influence pressures smoke movement, temperature distribution, critical Richard number (Ric) and height for were analyzed detail. A new prediction formula flow velocity considering different was modified. distribution beneath ceiling under developed. As result, model numbers to determine whether occurs proposed combining distribution. (hc) increases as decreases. Outcomes this study can provide references design natural ventilation system at higher altitude.