低空区域受地形和环境风的共同作用，形成复杂的干扰风场。本文在风洞中分别构建包含障碍尾流、空间约束和随机湍流的三类典型低空干扰风场，利用六分量天平测量旋翼非定常气动力和力矩，通过时-频联合分析，对比了不同工况和干扰位置下旋翼气动力影响规律。建立了基于延迟分离涡模拟（DES）的风场模拟方法，分析了不同干扰场景下旋翼-环境耦合流场特征。结果表明，空间约束引起的旋翼尾迹再循环会降低旋翼拉力，围合度越高削弱作用越严重。障碍物尾流区的大尺度周期性脱落涡会使旋翼遭受低频扰动，随着旋翼离地高度及与干扰物间水平距离的增大，流场中高频脉动增加，旋翼拉力功率谱峰值向高频迁移。随机湍流能量集中在高频段，对驾驶员工作负荷相关的低频敏感区影响较小。研究揭示了不同干扰场景下流动能量分布与旋翼气动力响应特征的内在关联，为旋翼飞行器的湍流抑制设计提供了理论依据。
The low-altitude environment for rotorcraft is characterized by complex wind fields resulting from the combined effects of terrain and wind conditions. This study investigates the aerodynamic interference mechanisms of three typical low-altitude wind fields on a rotor system, generated in a wind tunnel, including obstacle wake, spatial constraints, and random turbulence. Unsteady aerodynamic forces and moments acting on the rotor were measured using a six-component force balance. The influence of varying wind conditions and interference locations on rotor aerodynamic characteristics was assessed through time-frequency analysis. Furthermore, a disturbance wind field simulation method based on Detached Eddy Simulation (DES) is established. Numerical simulation results were then used to analyze the characteristics of the rotor-environment coupled flow field in various scenarios. The results reveal that rotor wake recirculation induced by spatial constraints decreases rotor thrust, and the reduction is exacerbated by increased confinement. The large-scale periodic vortex shedding within the obstacle wake region results in low-frequency aerodynamic perturbations. Increasing the rotor height above ground and the horizontal distance from the obstacle increases high-frequency fluctuations within the flow field, leading to a migration of the rotor thrust power spectrum peak towards higher frequencies. Random turbulence exhibits energy concentration in the high-frequency band, exhibiting a comparatively small effect on the low-frequency sensitive region associated with pilot workload. This research reveals the inherent relationship between energy distribution and rotor aerodynamic response characteristics under various scenarios, providing the theoretical basis for the design of turbulence suppression in rotorcraft.
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