Acoustic and Vibration Response of Flow-Excited Panels: Laboratory Reproduction and Panel Configuration Studies

外湍流边界层在飞行过程中总是存在于飞机机身周围，是巡航飞行中喷气式飞机座舱噪声的主要来源。在长时间暴露期间，高噪声水平会导致听力损失、疲劳、注意力不集中，并会影响呼吸频率、心脏功能和中枢神经系统。大多数飞机制造商都对更好地了解与飞机声学相关的物理学感兴趣。尽管人们的兴趣与日俱增，但人们对TBL引起飞机噪声的机制仍缺乏了解。此外，飞机噪声的飞行测量非常昂贵和耗时，因此，近年来，飞行条件的实验室再现引起了更多的关注。在这种背景下，本研究提案旨在促进对与TBL引起的噪声相关的物理以及对TBL激励的飞机壁板的声学和振动响应的实验室再现方面的最新进展。压电(PZT)致动器，战略性地嵌入测试面板，将用于激励结构，以再现面板对TBL的响应。将对不同的面板配置进行测试和分析，以研究实现降噪目标的最佳配置。拟议的研究将创建一个实验平台，为在实验室复制TBL激励的面板的声学和振动响应提供可靠的方法。实验数据的可获得性将使预测TBL激励结构的噪声和振动的计算方法得到验证。这项研究的成功结果将带来极具价值的知识，涉及创新技术的发展，这些技术可以应用于加拿大和国际的飞机工业。这项技术的获得将给飞机工业带来经济优势。此外，更好地了解TBL激励结构的实验和计算分析将有助于许多其他领域，如管道中的流体流动、发动机吊舱设计和汽车工业。

The external turbulent boundary layer (TBL), always present around the fuselage of an aircraft during flight, is typically the major source of jet aircraft cabin noise in cruise flight. During long exposure periods, high noise levels produce hearing loss, fatigue, loss of concentration, and can influence the respiratory rate, heart functions and central nervous system. Most aircraft manufacturers are interested in a better understanding of the physics associated with aircraft acoustics. In spite of the growing interest, there is still a lack of understanding of the mechanisms involved in TBL-induced noise in aircraft. Furthermore, in-flight measurements of aircraft noise are extremely costly and time-consuming, and therefore, the laboratory reproduction of in-flight conditions has attracted more attention in recent years. In this context, the present research proposal aims to advance the current state-of-the-art in the understanding of the physics associated with TBL-induced noise, and the laboratory reproduction of the acoustic and vibration response of TBL-excited aircraft panels. Piezoelectric (PZT) actuators, strategically embedded in the test panel, will be used to excite the structure, to reproduce the panel response to the TBL. Different panel configurations will be tested and analyzed, to investigate the best configuration for the noise reduction goal. The proposed research will create an experimental platform that enables the development of a solid methodology for the laboratory reproduction of the acoustic and vibration response of TBL-excited panels. The availability of experimental data will allow the validation of computational approaches for the prediction of noise and vibration of TBL-excited structures. The successful outcome of this research will bring extremely valuable knowledge involving the development of innovative technology, which can be applied to the aircraft industry, in Canada and internationally. The availability of this technology will bring an economic advantage to aircraft industry. In addition, a better understanding in both experimental and computational analysis of TBL-excited structures would benefit numerous other areas, such as, fluid flow in pipes, engine nacelle design, and the automotive industry.