大风速下火源横向位置对缓坡隧道烟气特性的影响

隧道火灾中，火源位置往往是不固定的。对于具有一定坡度的隧道，由于其特殊的建筑结构，一旦发生火灾，造成的危害相比其他类型的火灾要大得多。本文基于FDS软件对缓坡隧道进行了模拟分析计算，研究火源横向位置对隧道顶棚烟气分布、人体平均身高1.6 m处烟气速度流场矢量分布和顶棚烟气沿程温降分布规律的影响，并且与水平隧道的数值模拟结果对比分析。结果显示:隧道内顶棚烟气随火源与隧道壁距离的减小，由V型对称运动转为不对称的S型运动，火源一侧的流场趋势由正S型变为反S型，缓坡隧道较为明显，顶棚烟气温度沿出风口均是呈指数型减小，温降系数随火源与隧道壁距离的减小而增大，顶棚低温区逐渐向隧道壁靠近且范围逐渐增大，水平隧道的低温区范围比缓坡隧道要大。

Numerical Investigation Into the Influence of Different Transverse Fire Locations on Gentle Slope Tunnel Smoke Characteristics Under High Wind Speed

In actual tunnel fire, the fire source location is often not fixed. For a certain gradient tunnel, due to its special structure, in the event of a fire, the damage caused is much larger than other types of fire.Based on FDS software, this paper simulates and calculates the tunnel with a gentle slope tunnel.We investigated the effect of transverse position of fire source on the distribution of tunnel ceiling smoke, the vector distribution of flue smoke flow velocity at the height of 1.6 m and the distribution of temperature drop along roof flue smoke, and compared with the numerical simulation results of horizontal tunnel withhorizontal tunnel.The research results show thattunnel ceiling smoke with the tunnel wall and the distance decreases.From the symmetrical V-type movement to asymmetric S-type movement, gentle slope tunnel are noticeable, and ceiling flue gas temperature along the outlet are exponentially reduced, and the temperature coefficient increases with the decrease of the distance between the source of fire and the tunnel wall, and roof low temperature gradually approaches the tunnel wall and the range gradually increases, and horizontal tunnels have a lower temperature range than gentle slope tunnels.