Flow-induced sound and vibrations with applications to pipeline safety and mitigation of ocean noise pollution

流致振动和噪声（FIVN）是涉及内部和外部流动的各种工程系统中的重要问题。例如，它们可能导致用于输送流体的管道的振动和疲劳失效。此外，由于商业航运活动的加强和公众对其对环境影响的认识的提高，来自海洋船舶的噪声污染正在成为海洋工业、认证组织和公众的主要关切。 在多相流的存在下，准确预测FIVN是一个巨大的挑战。特别是，气穴现象（即液体流中形成蒸汽泡）会导致极高水平的辐射噪音。空泡通常发生在管道中的控制阀中以及船舶螺旋桨的非设计操作期间。所提出的计划将解决的关键问题，提高保真度的空化噪声模型，同时尽量减少相关的计算成本。我们的研究小组将采用实验和计算相结合的方法，并辅以理论建模，研究声音产生的基本机制。多相流体流动将通过求解非定常雷诺平均Navier-Stokes方程来模拟。液滴或气泡的形成将通过求解对应相的概率分布函数的方程来建模。此外，大涡模拟（LES）的方法将在选定的情况下。粒子图像测速技术（PIV）是物理实验中测量速度场的重要手段。结合声压测量的结果，将提供洞察声源的结构。 我在声耦合流领域有丰富的经验。此外，我们还与空化噪声测量（热那亚大学）和环境声学监测（JASCO Applied Sciences Ltd.）领域的领导者合作。将在推进基础知识及其实际应用方面做出重大贡献。除了改进目前用于被动声学监测的统计分析平台外，使用世界上最大的船舶噪声测量数据库（目前包含7000多艘船舶）验证开发的数学模型的能力使我们的研究小组在该领域取得了根本性的突破。在FIV控制和减轻海洋噪音污染领域培训高素质人员对加拿大具有战略重要性。在拟议的计划过程中，我将为9名研究生提供培训，这将对该领域产生长期影响。

Flow-induced vibrations and noise (FIVN) are important issues in a variety of engineering systems involving both internal and external flows. For example, they can lead to vibrations and fatigue failure of pipelines that are used for transporting fluids. Also, acoustic noise pollution from marine vessels is emerging as a major concern for the marine industry, certification organizations and the general public due to the intensified commercial shipping activity and increased public awareness of its impact on the environment. Accurate prediction of the FIVN presents a formidable challenge in the presence of multiphase flows. In particular, the cavitation phenomenon, i.e. formation of vapor bubbles in a liquid flow leads to extremely high levels of radiated noise. Cavitation commonly occurs in control valves in pipelines and during off-design operation of marine propellers. The proposed program will address the key issue of increasing fidelity of the cavitation noise models while minimizing the associated computational costs. Our research group will investigate the fundamental mechanisms of sound generation using a combined experimental and computational approach, complemented by theoretical modeling. Multiphase fluid flow will be simulated by solving the unsteady Reynolds-averaged Navier-Stokes equations. Formation of liquid droplets or gas bubbles will be modeled by solving an equation for the probability distribution function for the corresponding phase. In addition, a large eddy simulation (LES) approach will be employed in selected cases. Particle image velocimetry (PIV) will be used to measure velocity fields in physical experiments. The results, in conjunction with acoustic pressure measurements, will provide insight into the structure of the acoustic sources. I have extensive experience in the field of acoustically-coupled flows. Moreover, our collaborations with the leaders in the field of cavitation noise measurements (University of Genoa) and environmental acoustic monitoring (JASCO Applied Sciences Ltd.) will enable significant contributions both in terms of advancing fundamental knowledge and its practical application. In addition to improving the statistical analysis platform presently employed for passive acoustic monitoring, the ability to validate the developed mathematical models using the largest database of ship noise measurements in the world (presently containing over 7000 vessels) uniquely positions our research group for making a fundamental breakthrough in the field. Training of highly-qualified personnel (HQP) in the area of FIV control and mitigation of ocean noise pollution is of strategic importance to Canada. In the course of the proposed program, I will provide training to nine graduate students, which will lead to long-term impact in this field.