Sound and vibration in underwater and other structures

水下和其他结构中的声音和振动

• 批准号: 2089644
• 金额: --
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2089644
• 关键词: Sound; vibration; underwater; other; structures

This project aims to provide a fuller understanding of the vibrational and acoustic-radiation properties of engineering structures that are common in underwater applications and in aircraft design. Such bodies are typically composed of thin flexible plates (comprising the hull or fuselage), which are reinforced by bulkheads or ribs or other spatial inhomogeneities. The transmission of elastic waves along or through such structures is highly complex as the ribs act to scatter the waves into other vibrational modes, and the presence of the surrounding fluid also provides an alternate propagation route and coupling mechanism to generate acoustic waves.In this project the student will employ a range of advanced asymptotic and modelling techniques to understand better a number of key questions in this area, such as how to minimize the sound radiation from internal vibrational sources and how to reduce noise from the surrounding fluid impinging onto the vehicle itself. To make progress, a variety of simplified models shall be examined by analytical and computational methods, which exploit the disparity of lengthscales found naturally (building on the work discussed in [1]). The student will, as time allow, also consider the effects of coatings and other advanced 'smart' materials on sound emission and absorption.[1] P.A. Cotterill, W.J. Parnell, I.D. Abrahams, R. Miller, and M. Thorpe. The time-harmonic antiplane elastic response of a constrained layer. Journal of Sound and Vibration. 348: 167-184, 2015.

该项目旨在更全面地了解水下应用和飞机设计中常见的工程结构的振动和声辐射特性。这种船体通常由柔性薄板(包括船体或机身)组成，由舱壁或肋骨或其他空间不均匀件加固。弹性波沿着或通过这类结构的传播非常复杂，因为肋骨的作用是将波散射到其他振动模式，而周围流体的存在也提供了另一种传播路径和耦合机制来产生声波。在这个项目中，学生将使用一系列先进的渐近和建模技术来更好地理解这一领域的一些关键问题，例如如何最大限度地减少来自内部振动源的声音辐射，以及如何减少周围流体撞击到车辆本身的噪音。为了取得进展，各种简化的模型应通过分析和计算方法进行检查，这些方法利用自然发现的长度尺度的差异(建立在[1]中讨论的工作的基础上)。如果时间允许，学生还将考虑涂层和其他先进的“智能”材料对声音发射和吸收的影响。[1]P.A.Cotterill，W.J.Parnell，I.D.Abrahams，R.Miller和M.Thorpe。约束层的时谐反平面弹性响应。声学与振动杂志。348：167-184,2015。