Molecular Tagging Techniques for Stratified Flow: Application to Boundary Mixing

分层流的分子标记技术：在边界混合中的应用

• 批准号: 1067270
• 负责人: Chris Rehmann
• 金额: $ 25万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1067270&HistoricalAwards=false
• 关键词: Molecular; Tagging; Techniques; Stratified; Flow

1067270RehmannThe transport of heat, salt, and contaminants is important to measure and predict in environmental flows. For example, water quality in lakes depends on vertical transport of heat and contaminants, and the transport of heat and salt in the ocean affects the global climate. To improve the measurement and modeling of transport, molecular tagging velocimetry and thermometry (MTV&T), which has been applied successfully in other engineering flows, will be extended for use in stratified flows. The technique will be applied in a laboratory model of mixing driven by internal waves at the boundary of lakes and oceans. Specific objectives of the project are to (1) extend MTV&T to salt-stratified flow, (2) quantify turbulence and mixing generated by long waves, and (3) determine the effect of intermittent forcing on the mixing and transport.The intellectual merit of the proposed research comes from the ability to measure the mixing and turbulence in a boundary layer generated by internal waves in more detail than previously possible; MTV&T will provide two-dimensional fields of velocity, concentration, and flux while avoiding some of the pitfalls of other techniques. The proposed laboratory experiments start with a well-studied case to verify the molecular tagging technique and then extend previous laboratory work to study other factors that are important in interpreting field measurements. Concurrent field measurements will guide the design of the laboratory experiments and test the results from the lab. The proposed work exploits PI Rehmann's experience with measurements and modeling of boundary mixing and PI Hu?s expertise in advanced flow measurement and visualization techniques. The broader impacts include training a graduate student, conducting outreach to schools, and applying molecular tagging methods to stratified flow. The outreach uses the connections that Rehmann and Hu have established with Iowa schools and programs to broaden the participation of underrepresented groups. Also, the proposed project involves the first application of the molecular tagging method to a stratified flow of environmental importance; because previous field measurements have shown that boundary mixing can control the basin-wide vertical transport in lakes and oceans, these experiments will provide valuable information for modeling contaminant transport in the environment. Furthermore, once the proposed work demonstrates the usefulness of molecular tagging for boundary mixing, it can be used in laboratory models of many other stratified flows in the environment.

1067270HERMANN，热，盐和污染物的运输对于在环境流中进行测量和预测很重要。例如，湖泊中的水质取决于热和污染物的垂直运输，海洋中的热量和盐的运输会影响全球气候。为了改善转运的测量和建模，将成功应用于其他工程流中的分子标记速度计和温度法（MTV＆T）将扩展用于分层流。该技术将应用于由湖泊和海洋边界内部波驱动的实验室模型。该项目的具体目标是（1）将MTV＆T扩展到盐分层的流量，（2）量化长波产生的湍流和混合，以及（3）确定间歇性强迫对混合和运输的影响。拟议的研究的智力优点来自于以前由内部波浪中的边界层中的混合和湍流衡量的能力。 MTV＆T将提供二维速度，浓度和通量的场，同时避免其他技术的某些陷阱。拟议的实验室实验始于一个经过良好研究的案例，以验证分子标记技术，然后扩展以前的实验室工作，以研究对解释现场测量值很重要的其他因素。并发现场测量将指导实验室实验的设计，并测试实验室的结果。提出的工作利用了Pi Rehmann的经验，并在高级流量测量和可视化技术方面的边界混合和Pi Hu的专业知识进行了建模。更广泛的影响包括培训研究生，向学校进行宣传以及将分子标记方法应用于分层流程。外展使用了Rehmann和Hu与爱荷华州学校和计划建立的联系，以扩大代表性不足的群体的参与。同样，提出的项目涉及分子标记方法在环境重要性的分层流中的首次应用。由于以前的现场测量表明，边界混合可以控制湖泊和海洋中盆地范围的垂直运输，因此这些实验将为对环境中的污染物传输进行建模提供宝贵的信息。此外，一旦提出的工作证明了分子标记对边界混合的有用性，则可以将其用于环境中许多其他分层流的实验室模型中。