Collaborative Research: Development of Low Order Modeling Methods for Oscillating Foil Energy Harvesting based on Experimental and Computational Fluid Dynamics

基于水力或空气动力箔的振荡运动的替代能源系统，为目前尚未开发的大型和小型可再生能源（如潮汐、河流和小型风力发电场）的未来发展带来了希望。与旋转涡轮机相比，振荡系统具有重要的优势，因为它们可以在相对较低的频率下运行，对环境友好，并且由于叶片应力较低，它们的设计可以提高空气动力学效率。与这些能量收集器的开发和优化相关的一个关键的基本挑战是需要更好地理解影响设备性能的非线性流体动力学机制。该项目的目标是结合实验和计算分析来研究关键的底层流动物理，并开发低阶理论模型，以准确预测这些设备的功率提取潜力。该项目将通过俄勒冈州立大学SMILE和SEYES项目开展K-12外展活动，这些项目将大学预科学生带到俄勒冈州立大学校园进行研究体验。特别是，在大学URISE和STEM奖学金的帮助下，为本科生创建的动手风洞演示将使小学生和中学生接触到空气动力学研究。最后，一个开放获取的教科书，主要基于这个项目的要素，将提供给50多所大学的全国网络。该项目的具体目标是深入了解如何使用基于脉冲的全局模型准确有效地评估大规模低雷诺数粘性流动。该模型将通过仔细缩放实验和计算流场数据来发展，以解释运动学振荡运动。微分矩变换技术将应用于相平均流动动力学，以达到瞬态力的预测。将使用的方法包括相位分辨粒子图像测速和先进的混合ranss - les计算建模，以提供详细的随时间变化的流动分析。主要的技术目标是阐明？生命周期?这些流动中固有的大尺度涡旋结构的演变，并正确地模拟它们的动力学。除了提高对振荡箔系统复杂动力学的基本理解外，还将开发用于广泛振荡箔运动条件的低阶模型。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Alternative energy systems based on oscillating motion of hydro- or aerodynamic foils hold promise for future development of both large- and small-scale renewable energy resources that currently remain mostly untapped, such as tides, rivers, and small wind farms. Oscillating systems offer important advantages over rotary turbines because they can operate at relatively low frequencies, are environmentally friendly, and their designs can be more aerodynamically efficient due to lower blade stress. One key fundamental challenge associated with the development and optimization of these energy harvesters is the need for a better understanding of nonlinear fluid dynamic mechanisms that significantly impact device performance. The goal of this project is to combine experimental and computational analyses to investigate critical underlying flow physics and to develop low order theoretical models which can accurately predict the power extraction potential of these devices. The project will engage K-12 outreach through the Oregon State University SMILE and SEYES programs, which bring pre-collegiate students to the OSU campus for research experiences. In particular, hands-on wind tunnel demonstrations, created with the help of university URISE and STEM fellowships to undergraduate students, will expose elementary and high school students to aerodynamics research. Finally, an open access textbook, largely based on the elements of this project, will be made available to a national network of over 50 universities. Specific goals of this project are to develop a thorough understanding of how large-scale, low Reynolds number viscous flows can be accurately and efficiently evaluated using a global impulse-based model. This model will be developed through careful scaling of experimental and computational flow field data to account for kinematic oscillatory motion. The derivative moment transformation technique will be applied to phase-averaged flow dynamics to arrive at transient force predictions. The methodologies to be used include phase-resolved particle image velocimetry and advanced hybrid RANS-LES computational modeling to provide detailed time-dependent flow analysis. The primary technical objective is to elucidate the ?life cycle? evolution of large-scale vortical structures inherent in these flows and to correctly model their dynamics. In addition to improving fundamental understanding of the complex dynamics of oscillating foil systems, the low order models will be developed for a wide range of oscillating foil kinematic conditions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.