Abstract Mountain tunnel is inevitably connected to those canyon areas that could result in a very special situation for the related designs. When the airflow goes through the canyon from an open terrain, it is accelerated to a strong canyon wind under the Venturi effect. However, the flow characteristics in tunnels affected by the canyon wind are still not known. Therefore, the flow characteristics in the tunnel, such as structure, velocity and pressure distributions, together with external canyon wind, were investigated, for the first time, through this study. Different canyon wind velocities and tunnel types were analyzed numerically and experimentally. The results showed that the flow structure in tunnels can be divided into the vortex region and the uniflow region. Besides, a linear relationship was found between the average cross-section velocity of uniflow regions and the canyon wind velocity, where a quadratic relationship was also found between the minimum pressure of vortex regions and the canyon wind velocity. Furthermore, the results indicated that the flow characteristics in the tunnel induced by canyon wind are mainly affected by the hydraulic diameter of the tunnel, where the influences of different types of cross-sections with the same hydraulic diameter are limited.

中文翻译：

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峡谷风诱发隧道内流动特性研究

摘要 山地隧道不可避免地与峡谷区相连，这可能导致相关设计的特殊情况。当气流从开阔的地形穿过峡谷时，在文丘里效应下被加速成强烈的峡谷风。然而，受峡谷风影响的隧道中的流动特性仍然未知。因此，通过这项研究，首次研究了隧道内的流动特性，如结构、速度和压力分布，以及外部峡谷风。对不同的峡谷风速和隧道类型进行了数值和实验分析。结果表明，隧道内的流动结构可分为涡流区和单流区。除了，单流区平均截面速度与峡谷风速呈线性关系，涡流区最小压力与峡谷风速呈二次关系。此外，研究结果表明，峡谷风引起的隧道内流动特性主要受隧道水力直径的影响，相同水力直径的不同截面类型的影响有限。