MRI: Instrumentation for Large Scale Holographic Particle Image Velocimetry with a Sample Volume of 25x25x25 cm^3, 500^3 Velocity Vectors and High Speed Data Processing System

摘要CTS-0079674J。该项目的目标是开发和实施大规模全息粒子图像测速系统(HPIV)，用于测量复杂的湍流。这些数据将用于解决基本的湍流建模问题。该系统将使用500x500x500三维速度矢量阵列，以前所未有的规模分辨率测量高达25x25x25 cm^3的样本体积上的瞬时三维速度分布。湍流研究的两个主要途径提供了动力：i)高雷诺数湍流中速度增量的标度动力学和统计几何；ii)湍流中大尺度和小尺度之间的关系及其对大涡模拟(LES)亚网格尺度模拟的影响。三维数据将使PI和他的同事能够解决高阶结构函数的反常标度行为，这些高阶结构函数显著偏离Kolmogorov的预测；大涡模拟的湍流必须基于对不同长度尺度上湍流运动之间的相互作用的理解。这样的理解需要由分辨率良好的速度场组成的数据，这些数据可以被过滤以获得次网格尺度的应力、过滤后的速度及其梯度。这项技术的发展和改进最终将使其适用于广泛领域中具有重要意义的传输现象的整个研究人员社区。包括基础流体力学和应用流体力学、涉及气泡、颗粒和液滴运输的多相流以及环境流，如沉积物运移、大气科学(湍流和颗粒运移)和海洋学流动、颗粒和浮游生物动力学等方面的社区。

AbstractCTS-0079674J. Katz, Johns Hopkins UniversityThe objective of this project is to develop and implement a large scale Holographic Particle Image Velocimetry (HPIV) system for measuring complex turbulent flows. The data will be used for addressing fundamental turbulence modeling questions. The system will enable measurements of the instantaneous, three-dimensional velocity distribution over sample volumes of up to 25x25x25 cm^3, at an unprecedented resolution in scale, with arrays of 500x500x500, 3-D velocity vectors. Efficient and high speed processing tools will enable analysis of many holograms.Two main avenues of turbulence research provide motivation: i) scaling dynamics and statistical geometry of velocity increments in high Reynolds number turbulent flows, and ii) relationships between large and small scales in turbulence and their implications for subgird-scale modeling for Large Eddy Simulations (LES). The 3-D data will enable the PI and his colleagues to address the anomalous scaling behavior of high order structure functions that significantly deviate from Kolmogorov's predictions; Turbulence modeling for LES must be based on understanding of the interactions among turbulent motions at various length-scales. Such understanding requires data consisting of well-resolved velocity fields that can be the filtered to obtain the subgrid scale stresses, filtered velocity and its gradients.Development and improvements to this technology would eventually make it available to an entire community of researchers in a wide range of fields where transport phenomena are of significance. Included are communities involved in fundamental and applied fluid mechanics, multiphase flows involving transport of bubbles, particles and droplets as well as environmental flows, such as sediment transport, atmospheric sciences (turbulence and particle transport) and oceanography flow, particles and plankton dynamics, etc.).