跨介质飞行器的旋翼接近水面时，其下洗气流与水面相互作用会产生复杂的水气交混流场，旋翼在该流场中表现出与地面效应截然不同的气动特性，该现象被称为旋翼近水面效应。相较于单旋翼近水面效应，多旋翼在旋翼间的气动干扰以及各自诱导的水气交混流场的耦合作用下，其近水面效应将变得更加复杂。针对多旋翼近水面效应影响规律和影响因素尚未明晰的研究现状，本文开展了多旋翼近水面气动特性影响实验，对多旋翼近水面条件下不同桨尖间距与旋翼悬停高度下的气动力和转速进行了测量。并结合多旋翼近地面尾迹结构的相关研究与观察到的水气交混流场形态，初步建立了“合并、接触、分离”的多旋翼近水面效应认知框架。在不同水气交混流场状态下，间距最近的合并状态下具有最好的气动性能。随着间距增大，离水面相对较远的接触状态下旋翼无明显拉力损失，而在离水面较近的接触状态下旋翼拉力系数显著降低。此外，桨尖间距最远的分离状态下旋翼与水面作用产生的液滴与旋翼的强交互作用会导致旋翼扭矩剧增。
When the cross-media rotorcrafts approach the water surface, the interaction between its downwash flow and the water surface generates mixed air-water flows. In this flow field, the rotor exhibits aerodynamic characteristics distinctly different from in-ground effect, a phenomenon known as the near-water effect. Compared to the near-water effect of single-rotor, the near-water effect of multi-rotor becomes more complex due to the aerodynamic interference between rotors and the coupling of their respective induced mixed air-water flows. Given the current lack of understanding of the near-water effect of multi-rotor, this paper conducts experiments to investigate the aerodynamic characteristics of multi-rotors near the water surface, measuring the aerodynamic forces and rotational speeds under different blade tip clearances and hovering heights. Combining existing research on the near-ground wake structure of multi-rotors and the observed morphology of the mixed air-water flows, a preliminary cognitive framework of the near-water effect of multi-rotor is established, categorized as "merging, contacting and separating." Under different mixed air-water flows conditions, the merging mode with the closest clearance exhibits the best aerodynamic performance. As the clearance increases, the contacting mode at a relatively higher distance from the water surface shows no significant thrust loss, whereas the contacting mode closer to the water surface results in a notable reduction in the rotor thrust coefficient. Additionally, in the separating mode with the largest blade tip clearance, the strong interaction between the water droplets generated by the rotor-water interaction and the rotor leads to a sharp increase in rotor torque.
[1]刘安, 冯金富, 廖保全, 等.旋翼类飞行潜航器的发展及关键技术[J].舰船科学技术, 2017, 39(5):1-6
[2]ZENG Z, LYU C, BI Y, et al.Review of hybrid aerial underwater vehicle: Cross-domain mobility and transitions control[J/OL]. Ocean Engineering, 2022, 248: 110840.
[3]冯金富, 胡俊华, 齐铎.水空跨介质航行器发展需求及其关键技术[J].空军工程大学学报自然科学版, 2019, 20(3):8-13
[4]白兴之, 吴文华, 林泽铖, 等.旋翼近水面效应影响因素[J].空气动力学学报, 2023, 42(1):86-99
[5]BAI X, LU M, ZHAN Q, et al.Review of the Near-Water Effect of Rotors in Cross-Media Vehicles[JOL][J].Drones, 2025, 9(3):195-
[6]徐仁, 鞠世琦, 詹祺, 等.旋翼跨介质试验系统设计与性能实验研究[J].飞行力学, 2024, 42(3):89-94
[7]BAI X Z, ZHANG Z, WU W H, et al.Fluid Dynamics of Interacting Rotor Wake with a Water Surface[JOL][J].Drones, 2024, 8(9):469-
[8]BI Y, XU Z, SHEN Y, et al.Design and Implementation of a Bone-Shaped Hybrid Aerial Underwater Vehicle[JOL][J].IEEE Robotics and Automation Letters, 2024, 9(8):7318-7325
[9]WANG J, CHEN R, YU Z, et al.Ground test and numerical investigation on aerodynamic performance of a quad tilt-rotor aircraft in ground and water effects[J/OL]. Ocean Engineering, 2023, 289: 116169.
[10]ZHANG M, DUAN W, SHAO W, et al.Comparison of rotor hovering aerodynamic performance in free-surface and ground effects using numerical methods[JOL][J].Physics of Fluids, 2024, 36(10):106107-
[11]高世才, 王潇.旋翼跨介质飞行气动特性与机理仿真分析[J].空气动力学学报, 2025, 43(3):87-97
[12]詹祺, 徐尤松, 王潇.跨介质飞行器旋翼近水面气动干扰机理建模与研究[J]. 空气动力学学报, 2025: 1-11.
[13]ZHAN Q, WANG X, HU J, et al.Aerodynamic modeling and analysis of aerial-aquatic rotorcraft performance near and crossing the air-water interface[J/OL]. Chinese Journal of Aeronautics, 2025: 103511.
[14]HE X, LEANG K K.Quasi-Steady In-Ground-Effect Model for Single and Multirotor Aerial Vehicles[JOL][J].AIAA Journal, 2020, 58(12):5318-5331
[15]陆德顺, 张少谦, 王浩宇, 等.跨介质飞潜器水面起降过程流场及运动特性研究[J].水下无人系统学报, 2024, 32(3):434-450
[16]招启军, 倪同兵, 李鹏, 等.倾转旋翼机流动机理及气动干扰特性试验[J].航空动力学报, 2018, 33(12):2900-2912
[17]王畅, 马帅, 黄志银, 等.直升机涡环状态边界风洞试验研究[J].实验流体力学, 2023, 37(5):76-92
[18]DEKKER H N J, RAGNI D, BAARS W J, et al.Aerodynamic Interactions of Side-by-Side Rotors in Ground Proximity[J].
[19]TADGHIGHI H, RAJAGOPALAN R G.A user’s manual for ROTTILT solver: tiltrotor fountain flow field prediction[M/microform]. Hampton, Va.?: Springfield, VA: National Aeronautics and Space Administration, Langley Research Center?; National Technical Information Service, distributor, 1999.
[20]ZHOU W, NING Z, LI H, et al.An Experimental Investigation on Rotor-to-Rotor Interactions of Small UAV Propellers[J].
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