Hazardous weather, turbulence, wind, and thermals pose a ubiquitous challenge to Unmanned Aircraft Systems (UAS) and electric-Vertical Take-Off and Landing (e-VTOL) aircrafts, and the safe integration of UAS into urban area requires accurate high-granularity wind data especially during landing and takeoff phases. Two models, namely, Open-Source Field Operation and Manipulation (OpenFOAM) software package and Weather Research and Forecasting (WRF) model, are used in the present study to simulate airflow over Downtown Oklahoma City, Oklahoma, United States. Results show that computational fluid dynamics wind simulation driven by the atmospheric simulation significantly improves the simulated wind speed because the accurate modeling of the buildings affects wind patterns. The evaluation of different simulations against six Micronet stations shows that WRF-CFD numerical evaluation is a reliable method to understand the complicated wind flow within built-up areas. The comparison of wind distributions of simulations at different resolutions shows better description of wind variability and gusts generated by the urban flows. Simulations assuming anisotropy and isotropy of turbulence show small differences in the predicted wind speeds over Downtown Oklahoma City given the stable atmospheric stratification showing that turbulent eddy scales at the evaluation locations are within the inertial subrange and confirming that turbulence is locally isotropic.

中文翻译：

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使用耦合模拟改进城市空中交通的风速预测

危险天气、湍流、风和热气流对无人机系统 (UAS) 和电动垂直起降 (e-VTOL) 飞机构成无处不在的挑战，UAS 与城市区域的安全集成需要精确的高粒度风数据，尤其是在着陆和起飞阶段。本研究使用两个模型，即开源现场操作和操纵 (OpenFOAM) 软件包和天气研究与预报 (WRF) 模型来模拟美国俄克拉荷马州俄克拉荷马市市中心的气流。结果表明，由大气模拟驱动的计算流体动力学风模拟显着提高了模拟风速，因为建筑物的精确建模会影响风型。对六个 Micronet 站的不同模拟的评估表明，WRF-CFD 数值评估是了解建成区复杂风流的可靠方法。不同分辨率下模拟的风分布比较显示了对城市流动产生的风变化和阵风的更好描述。假设湍流各向异性和各向同性的模拟显示俄克拉荷马市中心的预测风速存在微小差异，因为稳定的大气分层表明评估位置的湍流涡流尺度在惯性子范围内，并确认湍流是局部各向同性的。不同分辨率下模拟的风分布比较显示了对城市流动产生的风变化和阵风的更好描述。假设湍流各向异性和各向同性的模拟显示俄克拉荷马市中心的预测风速存在微小差异，因为稳定的大气分层表明评估位置的湍流涡流尺度在惯性子范围内，并确认湍流是局部各向同性的。不同分辨率下模拟的风分布比较显示了对城市流动产生的风变化和阵风的更好描述。假设湍流各向异性和各向同性的模拟显示俄克拉荷马市中心的预测风速存在微小差异，因为稳定的大气分层表明评估位置的湍流涡流尺度在惯性子范围内，并确认湍流是局部各向同性的。