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学箔片的振荡运动的替代能源系统为未来开发大规模和小规模的可再生能源提供了希望，这些可再生能源目前大多尚未开发，例如潮汐，河流和小型风力发电场。 振荡系统提供了优于旋转涡轮机的重要优点，因为它们可以在相对低的频率下操作，是环境友好的，并且由于较低的叶片应力，它们的设计可以在空气动力学上更有效。 与这些能量采集器的开发和优化相关的一个关键基本挑战是需要更好地理解显著影响设备性能的非线性流体动力学机制。该项目的目标是将联合收割机的实验和计算分析相结合，以研究临界底层流动物理，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和高中学生接触空气动力学研究。最后，将向50多所大学组成的全国网络提供一本主要以该项目内容为基础的开放式教科书。该项目的具体目标是开发一个大规模的，低雷诺数粘性流如何可以准确和有效地使用全球脉冲为基础的模型进行评估的透彻理解。该模型将通过仔细缩放的实验和计算流场数据来解释运动学振荡运动。导数矩变换技术将应用于相平均流动动力学，以预测瞬态力。将使用的方法包括相分辨粒子图像测速和先进的混合RANS-LES计算建模，以提供详细的时间相关的流动分析。主要的技术目标是阐明？生命周期？这些流动中固有的大规模旋涡结构的演变，并正确地模拟其动态。除了提高对振荡翼系统的复杂动力学的基本理解外，还将为广泛的振荡翼运动学条件开发低阶模型。该奖项反映了NSF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.