摘要：通过城市街谷内单个车辆在任意时刻对空气的曳力计算, 提出更具一般意义的欧拉-拉格朗日方法, 实现对行驶车辆引起空气流动及湍流的模拟。模拟结果显示, 在不同的背景来流风速下, 行驶车辆对街谷内湍流有显著影响, 而对平均流场的影响相对较弱;行驶车辆诱导的湍流主要分布的靠近路面的区域, 且在靠近背风面的地方湍流强度增大最为显著;街谷内行驶车流诱导湍流强度及分布受背景来流风速的影响显著, 而受车辆行驶速度的影响相对较弱。街谷内行驶车流对风场的影响非常复杂, 简单地以车辆行驶速度或背景来流风速进行参数化的模型很难模拟不同情形下的流场特征。

关键词：城市街谷；湍流；风场；数值模拟；拉格朗日模型

Abstract：An Eulerian-Lagrangian method was further developed to simulate the moving vehicles induced air flows within urban street canyons. In the Lagrangian scheme, each vehicle was tracked and the vehicle induced drag forces on the surrounding air are formulated. Under different background wind velocities, the simulations show that, moving vehicles have much effect on wind turbulences, yet less effect on the average wind field within the street canyon. The presence of vehicle induced turbulences is near the ground, and the induced turbulence adrift near the leeward wall is larger than that in other areas within the street canyon. The vehicle induced turbulence under different background wind velocity in urban street canyons is hard to be parameterized by the vehicle speed or the ratio of vehicle speed over background wind velocity.

Keywords：urban street canyon; turbulent flow; wind field; numerical simulation; Lagrangian scheme