As a widely used fundamental transportation facility, tunnels always have a specific longitudinal slope, which may significantly affect smoke transportation, but the knowledge of smoke transportation in the sloped tunnel is relatively insufficient. In this work, a series of numerical simulations are performed to explore the influence of longitudinal slope on smoke transportation and temperature distribution in tunnels. The heat release rate ranges from 3 MW to 10 MW, and the tunnel slope varies from 0 % (horizontal tunnel) to 8 %. The outcomes of this work reveal that as tunnel slope and heat release rate rise, due to the growth of the induced air inflow velocity at the lower tunnel entrance, the fire plume and the high-temperature combustion region incline downstream of the tunnel. Consequently, the ceiling smoke needs to propagate a farther distance for approaching the one-dimensional spread stage. Moreover, a correlation to predict the smoke ceiling temperature distribution along the tunnel longitudinal direction is established by selecting the one-dimensional spread stage starting position as the reference point. Finally, for validating the applicability and reliability of the predictive equation, it is compared with the outcomes of previous small-scale and full-scale studies in horizontal and sloped tunnels.

中文翻译：

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隧道坡度对隧道火灾烟气运移和温度分布一维扩散的影响

隧道作为广泛使用的基础交通设施，往往具有特定的纵向坡度，这可能会显着影响烟气输送，但对倾斜隧道内烟气输送的认识相对不足。在这项工作中，进行了一系列数值模拟，以探讨纵向坡度对隧道内烟气输送和温度​​分布的影响。热释放率范围从3MW到10MW，隧道坡度从0%（水平隧道）到8%不等。这项工作的结果表明，随着隧道坡度和放热率的增加，由于隧道下部入口处诱导空气流入速度的增加，火羽和高温燃烧区域向隧道下游倾斜。因此，天花板烟雾需要传播更远的距离才能接近一维扩散阶段。此外，以一维扩散阶段起始位置为参考点，建立预测烟气顶板温度沿隧道纵向分布的相关性。最后，为了验证预测方程的适用性和可靠性，将其与之前水平和倾斜隧道小规模和全面研究的结果进行了比较。