Leveraging Metamaterials and Phase Control in ThermoAcoustic Systems

这一研究项目的目标是通过利用超材料和声波控制方面的创新概念来促进热声能发电领域的发展，从而造福于国家利益。这类系统通过为传统能源系统提供清洁和可持续的替代方案，有可能给现代能源发电带来革命性的变化。热声系统不涉及燃烧，因此缓解了人们对化石燃料能源在美国经济中的环境足迹的主要担忧。热声系统的实现有可能对广泛的应用产生影响，包括空间发电、太阳能回收和余热回收。几乎所有的热声系统都有两个固有的缺陷：低功率密度和设计复杂性。该奖项支持基础研究，通过利用动力学和控制工具以及声学超材料的独特滤波能力来解决这两个限制。该多学科项目将开发新的工具，以加强学生在动力学、声学和可持续能源发电领域的学习经验，并将通过一系列外联活动扩大代表性不足群体的参与。热声发生器(TAG)是一种设备，可以从热源自发产生强大的声波，然后以电力或机械运动的形式利用这些声波。它们有可能接近热力学强加的熵极限。该项目试图通过开发一种新型的基于超材料的标签来达到这一极限，该标签依赖于压力和速度之间的相位的最佳控制，以防止在声谐振器中形成永久驻波。在没有附加主体结构的情况下，达到了理想的声学条件。取而代之的是，热声堆小而复杂的孔中不可避免的非线性将被用来合成一种新的标签室，该标签室使行进热声波能够传播到谐振器的一端(在那里通过电声转换进行能量清除)，同时阻止边界反射。这项工作将把动态系统理论的工具与最先进的实验和实验室规模的研究结合起来。这一奖项反映了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。

This objective of this research project is to benefit the national interests by advancing the field of thermoacoustic energy generation using innovative concepts in metamaterials and acoustic wave control. Such systems have the potential to revolutionize modern-era energy generation by providing a clean and sustainable alternative to traditional energy systems. Thermoacoustic systems involve no combustion and therefore mitigate major concerns over the environmental footprint of fossil-fuel-based energy in the U.S. economy. The realization of thermoacoustic systems has the potential to impact a wide range of applications including space power generation, solar energy scavenging and waste heat recovery. Almost all thermoacoustic systems suffer from two inherent limitations: Low power density and design complexity. This award supports fundamental research to address both limitations by leveraging tools from dynamics and controls combined with the unique wave filtering capabilities of acoustic metamaterials. The multi-disciplinary project will develop new tools to enhance the learning experience of students in the fields of dynamics, acoustics and sustainable energy generation, and will broaden participation of underrepresented groups through a range of outreach activities. ThermoAcoustic Generators (TAGs) are devices engineered to spontaneously generate powerful sound waves from a heat source which are then harnessed as electricity or mechanical motion. They have the potential to approach the entropic limit imposed by thermodynamics. This project seeks to reach this limit by developing a novel class of metamaterial-based TAGs which rely on the optimal control of phasing between pressure and velocity which prevents the formation of permanent standing waves in the acoustic resonator. The desirable acoustic conditions are achieved without additional bulk structures. Instead, inevitable nonlinearities emerging from the small and complex pores of the thermoacoustic stack will be used to synthesize a new TAG chamber that enables traveling thermoacoustic waves to propagate to one end of the resonator (where energy scavenging takes place via electro-acoustic transduction) while impeding boundary reflections. This work will combine tools from dynamic systems theory with state-of-the-art experimental and laboratory-scale investigations.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.