The Mechanics and Acoustics of Bubbles Fragmenting in Sheared Flow.

剪切流中气泡破碎的力学和声学。

• 批准号: 0727140
• 负责人: Grant Deane
• 金额: $ 51.8万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0727140&HistoricalAwards=false
• 关键词: Mechanics; Acoustics; Bubbles; Fragmenting; Sheared

Wave-induced bubbles in the upper ocean drive a number of important oceanographic processes including air-sea gas fluxes, aerosol production and the scavenging of organic surfactants. The medium to large bubbles that persist for just a few seconds in the upper ocean during and immediately after wave breaking are thought to play a dominant role in the transport of carbon dioxide. Because it is difficult, for technological and logistical reasons, to make these measurements, there are very few data sets that characterize bubble distributions within whitecaps. Scientists at the Scripps Institution of Oceanography will conduct an experiment whereby bubbles in a turbulent fluid of various sizes will be fragmented. As the bubbles fragment they emit an acoustic signal that will be recorded with hydrophones. In addition, two cameras will record the details of the bubble breakup. The ultimate goal of the research is to determine bubble creation rates at the ocean surface. Although noise is known to come from bubbles as they form, the mechanisms that determine the amount of energy associated with the acoustic oscillations is not yet known. If it were, this work could lead to the development of a tool that allows one to measure bubble creation rates based upon ambient noise measurements. The experiment and data analysis will include the participation of an undergraduate intern.

上层海洋中的波浪诱导气泡驱动了许多重要的海洋学过程，包括海气通量、气溶胶产生和有机表面活性剂的清除。在波浪破碎期间和之后，在上层海洋中仅持续几秒钟的中型到大型气泡被认为在二氧化碳的运输中起着主导作用。由于技术和后勤方面的原因，很难进行这些测量，因此很少有数据集可以表征白浪中的气泡分布。斯克里普斯海洋学研究所的科学家们将进行一项实验，将不同大小的湍流中的气泡破碎。当气泡破碎时，它们会发出声波信号，水听器会将其记录下来。此外，两台摄像机将记录气泡破裂的细节。这项研究的最终目标是确定海洋表面气泡的产生率。虽然已知噪声来自气泡形成时，但决定与声学振荡相关的能量的机制尚不清楚。如果是这样的话，这项工作可能会导致一种工具的发展，这种工具可以根据环境噪声测量来测量气泡的产生速率。实验和数据分析将包括一名本科生实习生的参与。