INDUSTRIAL AEROACOUSTICS: PLANAR JETS AND CAVITY FLOWS

工业气动声学：平面射流和空腔流

• 批准号: RGPIN-2016-03667
• 负责人: Ziada, Samir
• 金额: $ 3.35万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614542
• 关键词: INDUSTRIAL; AEROACOUSTICS; PLANAR; JETS; CAVITY

Many flows in engineering applications are turbulent in nature and therefore produce pressure pulsations. A good design of a fluid mechanics device, that is safe, efficient and quiet, opts to maintain these pressure pulsations at an acceptably low level. However, in some cases involving flow separation and reattachment, such as impinging jets in painting and coating processes, or flow over architectural perforated panels, the flow turbulence can generate strong pressure pulsations. An example would be the pleasant tones of the flute, which are produced when the turbulence of the air stream being blown excites the sound waves inside the flute “pipe”. When similar phenomena occur in industrial applications, the resulting pressure pulsations are less benign than those of the flute. They can be sufficiently strong to generate dangerous excessive vibrations, deafening noise levels or cause structural failures and thereby endanger the safety and the environment of the work place and neighbouring communities. Even when the generated noise and vibration levels are sufficiently low and can be tolerated, the surface quality of the manufactured product can be degraded by the pressure pulsation. The objective of the proposed research is to advance the state of knowledge of the mechanisms generating pressure oscillations by impinging flows. The work will focus on two generic flow cases which are important for industrial applications. In the first case, the oscillations of two opposing planar jets are investigated and the effect of these oscillations on the surface quality at the edges of galvanized and painted objects is explored. Better understanding of these phenomena will benefit the galvanizing process of sheet steel for the automotive industry in Canada. The other task of the proposed work focuses on the cause of sound (noise) generation by flow over perforated panels used in the architectural industry. The results of both research tasks will be implemented in design guides to avoid the generation of pressure pulsation during the design stage to help improve the safety and the efficiency of these generic flow situations. Furthermore, since the proposed program combines fundamental investigations with industry-oriented research, it will constitute an excellent and attractive training ground for highly qualified personnel.

工程应用中的许多流动本质上是湍流的，因此会产生压力脉动。安全、高效和安静的流体力学装置的良好设计选择将这些压力脉动维持在可接受的低水平。然而，在涉及流分离和再附着的某些情况下，例如涂漆和涂覆过程中的冲击射流，或建筑穿孔板上的流动，流动湍流可产生强烈的压力脉动。一个例子是长笛的悦耳音调，这是当气流的湍流被吹激发长笛“管道”内的声波时产生的。当类似的现象发生在工业应用中时，所产生的压力脉动比长笛的压力脉动更不温和。它们的强度足以产生危险的过度振动、震耳欲聋的噪音或造成结构故障，从而危及工作场所和邻近社区的安全和环境。即使当所产生的噪声和振动水平足够低并且可以被容忍时，制造产品的表面质量也会由于压力脉动而劣化。所提出的研究的目的是推进国家的知识的机制产生的压力振荡的撞击流。这项工作将集中在两个通用的流动情况下，这是重要的工业应用。在第一种情况下，两个相对的平面射流的振荡进行了研究，并探讨了这些振荡对镀锌和喷漆物体边缘的表面质量的影响。更好地了解这些现象将有利于加拿大汽车工业钢板的镀锌工艺。建议的工作的另一个任务集中在声音（噪音）产生的原因，通过在建筑行业中使用的穿孔板的流动。这两项研究任务的结果将在设计指南中实施，以避免在设计阶段产生压力脉动，从而帮助提高这些通用流量情况的安全性和效率。此外，由于拟议的计划将基础调查与面向行业的研究相结合，它将成为高素质人才的优秀和有吸引力的培训基地。