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翼片振荡运动的替代能源系统为未来开发大型和小型可再生能源提供了希望，这些资源目前大多仍未开发，如潮汐、河流和小型风力发电场。与旋转涡轮机相比，振动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，而且由于叶片应力较低，其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了解显著影响设备性能的非线性流体动力学机制。该项目的目标是将实验分析和计算分析相结合，以研究临界底层流动物理，并开发能够准确预测这些器件的功率提取潜力的低阶理论模型。该项目将通过俄勒冈州立大学的微笑和SEYES计划，将K-12扩展到俄勒冈州立大学，这些计划将把预科学生带到俄勒冈州立大学的校园进行研究体验。特别是，在大学URISE和STEM奖学金的帮助下创建的动手风洞演示将使小学生和高中生接触到空气动力学研究。最后，将向由50多所大学组成的全国网络提供一本主要基于该项目内容的开放式获取教科书。该项目的具体目标是深入了解如何使用全球冲量模型来准确和有效地评估大规模、低雷诺数粘性流动。该模型将通过对实验和计算的流场数据进行仔细的缩放来考虑运动振荡运动。将导数矩变换技术应用于相平均流动动力学，以获得瞬态力的预测。将使用的方法包括相分辨粒子图像测速仪和先进的混合RANS计算模型，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？研究这些流动所固有的大尺度涡旋结构的演变，并正确地模拟其动力学。除了提高对振荡箔系统复杂动力学的基本理解外，低阶模型还将针对广泛的振荡箔运动学条件进行开发。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.