Acquisition of a Volumetric Velocimetry System

自然界中的流体流动本质上随时间和空间的变化而变化。同时绘制三维（3D）体积内的流场，不仅可以充分表征流场，还可以表征压力场以及流体内部和边界处的任何剪切力和法向力。这将对我们表征溶质混合、颗粒和溶质运输以及水生生物（从多孔介质中的微生物到河流中移动的鱼类）的能力产生变革性影响。该项目为购买体积测速系统（VVS）提供资金，以支持将在地球科学现象的物理模型中绘制流场的实验研究。VVS将为研究人员提供使用这种微创工具获得流动结构的体积实现的能力。该系统的应用实例包括对地表熔岩流爆发的模型研究，这将有助于预测熔岩何时到达指定位置。在第二个应用中，VVS将探索河床中溶质和沉积物颗粒运输的关键问题。例如，这些研究的结果将改进对河道稳定性的预测，并应用于河流修复工程的设计。最后，该系统对实验流场的体积描述将成为验证复杂计算模型的有力工具，尽管在许多情况下模型没有适当的数据作为基准，但计算模型正在成为一种常见的研究工具。突出VVS项目的网络存在将提供可视化和可用数据的链接。与当地一名中学教师的合作将促进当地学生参观爱达荷大学生态水力学研究中心。体积测速系统（VVS）的获得将使研究人员能够克服科学家和工程师所面临的关键共同挑战，他们寻求了解几种流体流动的基本性质：无法获得速度数据的所有三个时间和空间分辨分量及其空间和时间导数，这些信息将允许直接求解Navier-Stokes方程，检索压力和力分布的信息。此外，该系统对实验流场的体积描述将成为验证复杂计算模型的有力工具，这些模型正在成为一种常见的研究工具，尽管在许多情况下模型没有适当的数据作为基准。追求这些研究途径将产生对地球科学现象的见解，包括深海热液系统的夹带和表面熔岩流的爆发。此外，将VVS与折射率匹配相结合，将探讨微生物在孔隙间隙的定植、河床上和河床内的湍流耗散及其对生物的影响，以及河床中溶质和沉积物颗粒的输运等关键问题。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Fluid flows in nature vary intrinsically over space and time. Simultaneously mapping the flow field within a three-dimensional (3D) volume will allow the full characterization of not only the flow field, but also the pressure field and any shear and normal forces within the fluid and at boundaries. This will have a transformative impact on our ability to characterize solute mixing, particle and solute transport, and aquatic organisms, ranging from microorganisms within porous media to fish moving in a river. This project funds the acquisition of a Volumetric Velocimetry System (VVS) to support experimental research that will map flow fields in physical models of geoscience phenomena. The VVS will provide researchers the capability to acquire volumetric realizations of flow structures using this minimally invasive tool. Example applications of the system include model studies of breakout during surface lava flow which will improve prediction of when lava will arrive at specified location. In a second application, the VVS will probe critical questions about and solute and sediment grain transport in streambeds. Results from these studies will, for example, improve predictions of channel stability and be applied to the design of river restoration projects. Lastly, volumetric descriptions of the experimental flow fields from this system will be powerful tools for the validation of complex computational models, which are becoming a common investigative tool even though in many circumstances models are not benchmarked with proper data. A web presence highlighting VVS projects will provide visualizations and links to available data. A partnership with a local middle-school teacher will facilitate visits of local students to the Center for Ecohydraulics Research at University of Idaho. The acquisition of a Volumetric Velocimetry System (VVS) will enable researchers to overcome the crucial shared challenge faced by scientists and engineers who seek understanding of the fundamental nature of several types of fluid flows: the inability to acquire all three temporally and spatially resolved components of velocity data and their spatial and temporal derivatives, whose information will allow direct solution the Navier-Stokes equations retrieving information on the pressure and force distribution. Moreover, volumetric descriptions of the experimental flow fields from this system will be powerful tools for the validation of complex computational models, which are becoming a common investigative tool even though in many circumstances models are not benchmarked with proper data. Pursuing these research avenues will yield insights into geoscience phenomena, including entrainment in deep-sea hydrothermal systems and breakout during surface lava flows. In addition, coupling the VVS with the refractive index matching will probe critical questions about microbial colonization of pore interstices, turbulence dissipation at and within streambeds and its impact on organisms, and solute and sediment grain transport in streambeds.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.