UNS: Deconstructing Complex Flight Aerodynamics by Data-Driven Identification of Low Order Non-linear Motion Models

1510797(塔夫提)这项提议旨在研究蝙蝠翅膀周围的非定常流动，并揭示导致蝙蝠高度机动性飞行的流体动力学现象。蝙蝠的翅膀与鸟类和昆虫的翅膀有很大的不同，这些差异使它们能够适应不同的飞行条件。这项拟议工作的结果可能会有广泛的应用，从自主飞行器的设计到开发更高效的涡轮机以提取风能或水流能量，满足国家在能源研究方面的需求。研究目标是研究能够提供独特机动性和飞行效率的柔性拍动膜状机翼周围的流体动力学。蝙蝠可以控制它们的翅膀拍打的幅度和频率、拍面、翼膜变形、翅膀弧度、翅膀面积和展宽比，在一个非常复杂的综合运动中。目前在了解扑翼飞行力学方面的许多工作不适用于这种多关节机翼运动以及在蝙蝠飞行过程中观察到的非定常流体动力学。人们建议利用飞行实验和计算来了解蝙蝠飞行的机理。飞行测量将用活蝙蝠进行，使用冗余配置的3D高分辨率摄像头，以生成完整、详细和准确的飞行机动运动数据。这些图像将被分析，以产生位于蝙蝠身体上的固定点的运动学描述。在飞行数据的基础上，建立了扑翼飞行低维动力学模型的一般而严格的公式。我们的目标是识别表征飞行动力学和机翼上的诱导力的低维流形。该方法可以看作是本征正交分解(POD)方法的一种扩展，以考虑更广泛的一类非线性低阶机翼运动模型，并由所得到的非定常气动力进行验证。该项目将积极招募合格的少数族裔候选人，并通过弗吉尼亚理工大学、ADVANCEVT计划以及HBCU和多数拉美裔服务机构的少数族裔学生来利用这一活动。PIS将继续参与VT工程学院CEED方案，以招募和推广K-12女性和少数族裔。

1510797(Tafti)This is a proposal to investigate the unsteady flow around the wings of a bat and to uncover the fluid dynamics phenomena that are responsible for the highly maneuverable flight of bats. Bat wings are very different than wings of birds and insects, and these differences allow them to adapt to different flight conditions. Results from the proposed work could have wide-ranging applications from the design of autonomous flying vehicles to the development of more efficient turbines for the extraction of wind or water current energy, addressing a National need in energy research.The research objective is to study the fluid dynamics around flexible, flapping membrane-like wings that can provide unique maneuverability and flight efficiency. Bats can control their wing beat amplitude and frequency, stroke plane, wing membrane deformation, wing camber, wing area and aspect ratio in a synthesis of a very complex motion. Much of the current work in understanding the mechanics of flapping flight is not applicable for such multi-articulated wing motion and the ensuing unsteady fluid dynamics observed during bat flight. It is proposed to use flight experiments and computations to understand the mechanics of bat flight. Flight measurements will be conducted with live bats using 3D high-resolution cameras in redundant configurations to generate complete, detailed and accurate motion data of maneuvering in flight. The images will be analyzed to produce kinematic descriptions of fixed points located on the bat body. Based on the flight data, a general and rigorous formulation for deriving low dimensional dynamic models of flapping flight will be developed. The goal is to identify the low-dimensional manifolds that characterize the flight dynamics and the induced forces on the wings. The approach can be viewed as an extension of the proper orthogonal decomposition (POD) method to consider a wider class of nonlinear, low-order models of wing motion validated by the resultant unsteady aerodynamics. The project will actively recruit qualified minority candidates and leverage this activity through the Virginia Tech, ADVANCEVT program and minority students from HBCUs and majority Hispanic serving institutions. The PIs will continue their participation in the VT College of Engineering CEED program for recruiting and outreach to K-12 women and minorities.