Lift Management for Unsteady Translating Wings Using a Rotating, Swept Wing Tip

无人机在社会上的作用越来越大，无论是民用还是国防应用。一个关键的研究领域是开发能够在复杂环境中单独或成群机动的小型敏捷无人机。这些场景包括搜索和救援行动，追踪有毒气体羽流，或收集城市交通模式等大规模数据。然而，由于湍流和阵风，这些飞行器在机动过程中容易失去控制。该项目将通过实时修改翼尖形状来更好地理解和防止这种失控，以便在这些情况下控制升力。在水箱中进行的成像和升力测量将为改进未来的飞行控制系统提供预测数学模型。该项目还有一个外联计划，重点是指导女高中生、本科生和研究生，并通过实践研究吸引她们。本研究的目的是研究可变翼尖在大攻角非定常平动过程中控制动失速机翼的气流相干性和升力的可行性。在这种情况下，一个旋涡，低压前缘涡在机翼上形成，产生很大的升力，但随后脱落。拟议的可移动翼尖将利用尖涡控制来增加大攻角机动的升力或减少阵风的升力。所提出的可变翼尖是独特的，结合了旋转和后掠，这应该产生更紧密和连贯的涡流和实质性的升力控制。实验将在水箱中使用比例模型进行，使用染料可视化，力测量和立体粒子图像测速法进行3D速度重建。实验结果将用于开发改进飞行控制方法的预测模型。

Drone aircraft have an ever-increasing role in society, with both civilian and defense applications. A key research area is the development of small-scale, agile drones that can maneuver alone or in groups in complex environments. Such scenarios include search-and-rescue operations, tracking a toxic gas plume, or collecting large-scale data such as city traffic patterns. However, these vehicles are susceptible to loss of control during maneuvers because of turbulence and wind gusts. This project will seek to better understand and prevent this loss of control by modifying the wing-tip shape in real-time in order to control the lift force in these scenarios. Imaging and lift measurements in a water tank with a scaled wing model will lead to a predictive mathematical model for improved future flight-control systems. This project also has an outreach plan that focuses on mentoring female high-school, undergraduate, and graduate students and engaging them through hands-on research.The objective of the proposed research is to investigate the viability of a variable wing tip to control the flow coherence and lift for a dynamically-stalled wing during high-angle-of-attack, unsteady translation. In this scenario, a swirling, low-pressure leading-edge vortex forms over the wing and yields large lift, but then sheds. The proposed moveable wingtip will exploit tip-vortex control to increase lift for high-angle-of-attack maneuvers or reduce lift for gust alleviation. The proposed variable wing tip is unique, combining rotation with aft sweep, which should produce a more attached and coherent vortex flow and substantial lift control. Experiments will be performed with scaled models in a water tank, using dye visualization, force measurements, and stereo particle image velocimetry for 3D velocity reconstructions. The experimental results will be used to develop a predictive model for improved flight-control methods.