A 3-D Acoustic Current Meter for Upper Ocean Measurements

用于上层海洋测量的 3D 声学海流计

• 批准号: 9314357
• 负责人: Albert Williams
• 金额: $ 61.2万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-07-01 至 1998-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9314357&HistoricalAwards=false
• 关键词: Acoustic; Current; Meter; Upper; Ocean

OCE93-14357 Williams The Woods Hole Oceanographic Institution will undertake an Ocean Sciences Instrumentation development project to develop a low-cost, modular 3-D acoustic current meter for moored, upper ocean measure- ments. The development will be accomplished in incremental steps building from the existing Benthic Acoustic Stress Sensor (BASS); through a single sensor cable suspended instrument; to a self- contained flux meter configuration; and finally to a modular, expendable velocity sensor. At each step, the prototype will be tested in an experimental program. The self-contained flux meter will be tested in DOE's Ocean Margin Program, and the modular velocity sensor will be tested as a Richardson number float in association with a separate NSF project. During at sea testing, an acoustic vorticity meter will be deployed to measure the shear and turbulence associated with 3-D coherent motions of the Langmuir type. Each prototype including the vorticity meter, will be tow or tank tested to determine its flow distortion, wake obstruction, vortex shedding and compass response. Measurement of flow is a first order task in ocean studies, yet except for several specialized studies such as turbulence in boundary layer flows, one depends on two axis velocity measurements from expensive (as opposed to expendable) current meters for this flow determination. There are now three general research areas where 3-D current meters are needed: in near surface measurements where coherent 3-D motions are present and where surface and internal waves produce significant vertical flow; in transport studies where the product of vector flow with a scalar quantity must be averaged over time and depth and perhaps across a section; and in vorticity resolving arrays for determining shear in the presence of wave motions. The most promising transitions to a 3-D solution today are acoustic techniques and this project builds upon experience with an acoustic vector veloc imeter to address each of these tasks.

OCE93-14357 Williams 伍兹霍尔海洋研究所将承担海洋科学仪器开发项目，开发低成本、模块化 3D 声学海流计，用于停泊、上层海洋测量。 该开发将在现有的底栖声应力传感器（BASS）的基础上逐步完成； 通过单传感器电缆悬挂仪表；独立的通量计配置；最后是模块化、一次性速度传感器。 在每一步中，原型都将在实验程序中进行测试。 独立的通量计将在美国能源部的海洋裕度计划中进行测试，而模块化速度传感器将作为与单独的 NSF 项目相关的理查森浮子进行测试。 在海上测试期间，将部署声涡度计来测量与朗缪尔型 3D 相干运动相关的剪切和湍流。 包括涡度计在内的每个原型都将进行牵引或水箱测试，以确定其流动畸变、尾流阻碍、涡流脱落和罗盘响应。 流量测量是海洋研究中的首要任务，但除了边界层流中的湍流等几项专门研究外，流量测定还依赖于昂贵（而不是消耗性）海流计的两轴速度测量。 现在有三个需要 3D 海流计的一般研究领域： 在近地表测量中，存在相干 3D 运动，并且表面波和内波产生显着的垂直流；在交通研究中，矢量流与标量的乘积必须在时间和深度上（也许在一个截面上）进行平均； 以及用于确定存在波浪运动时的切变的涡度解析阵列。 当今向 3D 解决方案最有希望的过渡是声学技术，该项目基于声学矢量测速仪的经验来解决这些任务。