ABSTRACT

In this work, the flow conditions are numerically investigated inside uniform and non-uniform street canyons well within the atmospheric boundary layer. The numerical simulations use the steady-RANS method with the near-wall modelling approach to simulate wall roughness at the boundary. With the aim of investigating both flow structure in broad terms and pedestrian comfort in the street canyon between parallel buildings, we test different canyon configurations with varied street width, building width and building height. Turbulent conditions are broadly expected to hold within the physically realistic range of Reynolds number of order ${10}^6$ considered here, where we take the building height to be a characteristic length scale and the free stream velocity as the characteristic velocity. In addition to discussing the features of the canyon and wake flow, we investigate the effects of canyon geometry on pedestrian comfort by using the Extended Land Beaufort Scale for this purpose. We present and compare pedestrian comfort ‘maps’ for each of our geometries.

摘要

在这项工作中，对大气边界层内均匀和非均匀街道峡谷内部的流动条件进行了数值研究。数值模拟使用稳态RANS方法和近壁建模方法来模拟边界处的壁粗糙度。为了全面研究平行建筑物之间街道峡谷中的流动结构和行人舒适度，我们测试了具有不同街道宽度，建筑物宽度和建筑物高度的不同峡谷构造。广泛预期湍流条件将保持在雷诺数阶的物理现实范围内${10}^6$在这里考虑，我们以建筑物的高度为特征长度尺度，以自由流速度为特征速度。除了讨论峡谷和尾流的特征外，我们还为此目的使用扩展土地博福特量表研究了峡谷几何形状对行人舒适度的影响。我们提供并比较了每个几何图形的行人舒适度“地图”。