城市风效应对建筑密集低空空域无人机运行的影响
Urban Wind Effects on UAV Operations in Building-Dense Low-Altitude Airspace
AI总结：
针对建筑密集城市低空空域，提出一种基于LBM风场和轨迹包络的通用基准方法，用于在航线固定前评估风致净空风险，并在上海和北京验证了其识别净空敏感区域的能力。
AI中文摘要：
城市低空无人机（UAV）运行受建筑改性风以及受限的地形-建筑净空约束的共同影响。空间异质风会扰动短时域运动，但其净空后果取决于局部空域：相似的扰动在开阔区域可能保持良性，但在建筑墙壁、屋顶边缘或高地地形附近可能变得对净空敏感。本研究开发了一种在航线缓冲区或走廊对齐固定之前进行早期净空评估的通用基准方法。对于每个位置-高度状态，使用共享航向和采样设计生成标称和受风影响的飞行器尺寸轨迹包络，分离固定支撑风载荷、初始净空暴露和风致净空变化。应用于上海和北京时，该方法使用与20米地形-建筑场景网格配准的格子玻尔兹曼方法（LBM）风场，高度层为60-340米，并采用一架代表性轻型无人机。结果表明，基线风载荷和净空暴露存在显著的空间和垂直模式。受风影响的包络在净空暴露方面产生较小的全域中位数偏移，但在归一化净空暴露尺度上，在较低高度层产生空间集中的上尾响应。千米瓦片级分析将这些响应主要与基线净空敏感性和水平风梯度大小联系起来，固定支撑风载荷和平均风速起次要作用。低空规划应区分风载荷位置与净空敏感位置。作为上游诊断，该方法识别出标称轨迹包络接近地形-建筑边缘且局部风变化可能进一步改变净空暴露的单位，其中增加集中在上尾。
英文摘要：
Urban low-altitude uncrewed aerial vehicle (UAV) operations are shaped by building-modified wind and constrained terrain-building clearance. Spatially heterogeneous wind can perturb short-horizon motion, but its clearance consequence depends on local airspace: similar perturbations may remain benign in open areas yet become clearance-sensitive near building walls, roof edges, or elevated terrain. This study develops a common-basis method for early clearance assessment before route buffers or corridor alignments are fixed. For each position-height state, nominal and wind-affected vehicle-sized trajectory envelopes are generated with a shared heading and sampling design, separating fixed-support wind loading, initial clearance exposure, and wind-induced clearance change. Applied to Shanghai and Beijing, the method uses lattice-Boltzmann method (LBM) wind fields co-registered with 20 m terrain-building scene grids, height layers of 60-340 m, and a representative light UAV. Results show distinct spatial and vertical patterns in baseline wind loading and clearance exposure. Wind-affected envelopes produce little domain-wide median shift in clearance exposure but generate spatially concentrated upper-tail responses in lower-altitude layers on the normalized clearance-exposure scale. Kilometer-Tile-level analysis links these responses mainly to baseline clearance sensitivity and horizontal wind-gradient magnitude, with fixed-support wind loading and mean wind speed playing secondary roles. Low-altitude planning should distinguish wind-loaded locations from clearance-sensitive locations. As an upstream diagnostic, the method identifies units where nominal trajectory envelopes approach terrain-building margins and local wind variation may further alter clearance exposure, with increases concentrated in the upper tail.
