Computational fluid dynamics (CFD) results generated by the steady Reynolds-averaged Navier-Stokes equations (SRANS) model and large eddy simulation (LES) are compared with wind tunnel experiments for investigating a cross-ventilation flow in a group of generic buildings. The mean flow structure and turbulence statistics are compared for SRANS based on different two-equation turbulence models with LES based on the Smagorinsky subgrid-scale turbulence model. The LES results show very close agreement with the experimental results in the prediction of the time-averaged velocity, wind surface pressure around and inside the building, and crossing flow through the openings. In contrast, SRANS fails to predict the most important features of cross-ventilation. LES reproduces well the anisotropic turbulence property around and inside the cross-ventilated building, which is closely related to the transient momentum transfer caused in street canyon flows and has a significant influence on the mean flow structure. In contrast, SRANS could not inherently reproduce such transient fluctuations and anisotropic turbulence property, which results in low accurate predictions for the time-averaged velocity components, wind surface pressure distribution and crossing airflow rate up to 100% error.

将稳态雷诺平均Navier-Stokes方程（SRANS）模型和大涡模拟（LES）生成的计算流体动力学（CFD）结果与风洞实验进行比较，以研究一组通用建筑物中的交叉通风流。比较了基于不同二方程湍流模型的SRANS和基于Smagorinsky亚网格规模湍流模型的LES的平均流结构和湍流统计数据。LES的结果与时间平均速度，建筑物周围和内部的风面压力以及穿过开口的横流的预测中的实验结果非常吻合。相反，SRANS无法预测交叉通气的最重要特征。LES很好地再现了交叉通风建筑物周围和内部的各向异性湍流特性，这与街道峡谷流动中引起的瞬态动量传递密切相关，并且对平均流动结构具有重大影响。相比之下，SRANS无法固有地重现这种瞬态波动和各向异性湍流特性，从而导致对时间平均速度分量，风面压力分布和穿越气流速率的准确预测值较低，误差高达100％。