Development of Acoustic Energy Concepts to Characterize and Control Acoustic Fields

声能概念的发展以表征和控制声场SommerFeldt、Leishman和BlotterAbstra在过去的二十年中，声强技术在声场的理解和表征方面取得了显著的进步。然而，与声能量相关的几个基本问题以及它们在描述和控制声场方面的意义仍然存在。该项目将重点研究封闭声场中的几个能量值，以更充分地了解它们的空间相关性，以及基于能量的传感和驱动如何在一些重要应用中得到有利的利用。具体目标是：(1)在应用于封闭声场时，将深入分析包括声能密度、拉格朗日密度及其空间导数在内的能量量；(2)将开发测量技术，用于测量理想(无回声和漫反射)声场以及更一般的声场环境中的声功率；(3)将开发先进的有源噪声控制概念，进一步使用基于能量的测量来改进对声场的全局控制；(4)将利用基于能量的测量和自适应信号处理开发声场均衡技术。这项研究将结合分析、数值和实验研究。首先，将对这些能量值及其空间导数的空间相关性进行解析研究，以确定用于不同应用的最佳能量值。数值工作将把这些概念扩展到非理想条件，并将被用来调查这些基于能量的概念如何在目标应用中使用，以及它们将如何执行。最后，将对所开发的概念进行实验验证。该项目将通过发现新的基于能源的关系和测量技术来促进科学知识的发展。这项研究通过在从房间声学到飞机机身的各种应用中增强噪音控制技术，具有显著的社会效益。通过这项研究，未来的专业人员将被培养成具有强大的研究技能和广泛的声学和结构动力学背景。研究生和本科生将参与到团队中，并将学习如何有效地彼此互动。将支持和鼓励这些小组在技术会议上发表和介绍他们的研究成果。

DEVELOPMENT OF ACOUSTIC ENERGY CONCEPTS TO CHARACTERIZE AND CONTROL ACOUSTIC FIELDSSommerfeldt, Leishman, and BlotterAbstractOver the past twenty years, acoustic intensity techniques have led to significant improvements in the understanding and characterization of acoustic fields. However, several fundamental questions associated with acoustic energy quantities, and their significance in characterizing and controlling sound fields still exist. This project will focus on investigating several energy quantities in enclosed sound fields to more fully understand their spatial dependence and how energy-based sensing and actuation can be used advantageously in a number of important applications. The specific objectives are: (1) Energy quantities including acoustic energy density, Lagrangian density, and their spatial derivatives will be analyzed in depth, as they apply to enclosed sound fields; (2) measurement techniques will be developed for measuring sound power, both in ideal (anechoic and diffuse) acoustic fields, as well as more general acoustic environments; (3) advanced active noise control concepts will be developed that further use energy-based measurements to improve the global control of acoustic fields; and (4) sound field equalization techniques will be developed using energy-based measurements and adaptive signal processing. This research will couple analytical, numerical, and experimental investigations. First, an understanding of the spatial dependence of these energy quantities and their spatial derivatives will be investigated analytically to identify the best energy quantities to measure for the different applications. Numerical work will extend these concepts to non-ideal conditions, and will be used to investigate how these energy-based concepts could be used in the target applications, and how they would be expected to perform. Finally, experimental verification of the concepts developed will be performed. This project will advance scientific knowledge through the discovery of new energy-based relationships and measurement techniques. This research has potential for significant societal benefits by enhancing noise control techniques in applications ranging from room acoustics to an aircraft fuselage. Through this research, future professionals will be trained with strong research skills and broad backgrounds in acoustics and structural dynamics. Graduate and undergraduate students will be involved on teams, and will learn to effectively interact with one another. These teams will be supported and encouraged to publish and present their research at technical meetings.