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Flow Control for Unsteady Aerodynamics of Pitching/Plunging Airfoils

俯仰/俯冲翼型非定常空气动力学的流量控制

基本信息

批准号：
317970247
负责人：
Professor Dr.-Ing. Cameron Tropea
金额：
--
依托单位：
Fachgebiet Strömungslehre und Aerodynamik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/317970247?language=en
关键词：
Flow Control Unsteady Aerodynamics Pitching

项目摘要

This project examines some generic flow control schemes for unsteady aerodynamics. In the context of this proposal unsteady aerodynamics are flow situations in which the boundary conditions exhibit time dependence. Such flows are a very common occurrence in a large number of practical applications, such as rotorcraft blades, wind turbine blades, flapping flyers or in aircraft or ground vehicles subject to turbulence and/or gusts. The proposed project considers such flows, but examines especially the possibility of introducing flow control measures, either to mitigate unwanted effects of the unsteadiness or to improve overall performance or lifetime of components. The combination of unsteady aerodynamics and flow control is a rather new research field and therefore generic configurations are chosen to explore the physics involved and the achievable control authority. In particular the leading and trailing edge vortex formation found in pitching and plunging airfoils are considered representative and suitable for such pioneering studies. The aerodynamic consequence of these vortices, which develop on the airfoil and separate after some finite growth time, can be either beneficial or detrimental, depending on application. Detrimental effects include deteriorated overall aerodynamic performance (deep stall, lift hysteresis), accelerated fatigue, or increased vibration and noise. On the other hand, vortices on an airfoil can also enhance lift, as used in insect flight and, to some extent, on helicopters. The actuators to be used in this study for flow control are the dielectric barrier discharge (DBD) plasma actuator and the synthetic jet actuator. Both are fast acting and are suitable to be integrated into either open-loop or closed-loop control strategies; hence capable of mitigating unwanted effects due to unexpected and/or unknown on-flow perturbations. The scientific goals of the project include postulating, through reference experiments and numerical simulations, the most appropriate placement and operation of the actuators, and verification of the control strategy through experiment and simulation. The outcome of the project would be an increased understanding of the control authority of the actuators and specific recommendations for implementation in real-world applications.

本计画探讨非定常空气动力学的一般性流动控制方案。在这个建议的范围内，非定常空气动力学是边界条件表现出时间依赖性的流动情况。这种流动在大量的实际应用中是非常常见的，例如旋翼机叶片、风力涡轮机叶片、扑翼飞行器或在经受湍流和/或阵风的飞行器或地面车辆中。拟议的项目认为，这种流量，但特别是审查引入流量控制措施的可能性，无论是减轻不必要的影响的不稳定性或提高整体性能或组件的寿命。非定常空气动力学和流动控制的结合是一个相当新的研究领域，因此选择通用配置来探索所涉及的物理和可实现的控制权威。特别是在俯仰和俯冲翼型中发现的前缘和后缘涡的形成被认为是具有代表性的，并且适合于这种开创性的研究。这些涡流在翼型上发展，并在有限的增长时间后分离，其空气动力学后果可能是有利的，也可能是有害的，这取决于应用。有害影响包括总的空气动力性能恶化（深度失速、升力滞后）、加速疲劳或增加振动和噪音。另一方面，机翼上的涡流也可以增强升力，如昆虫飞行中所使用的，在某种程度上，也可以用于直升机。在这项研究中使用的致动器用于流量控制的介质阻挡放电（DBD）等离子体致动器和合成射流致动器。两者都是快速作用的，并且适合于集成到开环或闭环控制策略中;因此能够减轻由于意外和/或未知的流动扰动而引起的不必要的影响。该项目的科学目标包括通过参考实验和数值模拟假设致动器的最适当放置和操作，并通过实验和模拟验证控制策略。该项目的成果将是增加对执行器控制权限的理解，并提出在实际应用中实施的具体建议。