Effect of Slope on Smoke Propagation in an Urban Traffic Tunnel Fire

The effect of slope on smoke propagation in an urban traffic tunnel fire scenario under natural ventilation is studied by large eddy simulation. For a tunnel of range from no 5 degrees slope, the transverse and lognitudinal temperature distributions of smoke layer, the highest temperature on tunnel ceiling are computed. These numerical results are compared with those of tunnel with corresponding horizontal tunnel. It has been found that the slope has a great effect on smoke temperature along longitudinal direction. Especially in the ascending part downstream of fire source, smoke layer descends quickly. The highest temperature position on tunnel departures from the upper point of fire source on downhill side. But the highest temperature of 5% slope does not vary greatly by comparison of that in tunnel of zero slope. These results can provide reference on fire protection design of urban traffic tunnel.