A scalar imaging velocimetry technique for fully resolved four‐dimensional vector velocity field measurements in turbulent flows

Scalar imaging velocimetry measurements of the velocity gradient tensor field in turbulent flows. I. Assessment of errors

The concept of flow field velocimetry based on scalar imaging measurements @Phys. Fluids A 4, 2191 ~1992!# is here formulated in terms of an integral minimization implementation, where the velocity field u~x,t! is found by minimizing weighted residuals of the conserved scalar transport equation, along with the continuity condition and a smoothness condition. We apply this technique to direct nu...

AlAA 94-0403 Scalar Imaging Velocimetry Studies of the Dissipative Scales of Motion in Turbulent Flows

Passive Scalar Equation in a Turbulent Incompressible Gaussian Velocity Field

Time evolution of a passive scalar is considered in a turbulent homogeneous incompressible Gaussian flow. The turbulent nature of the flow results in non-smooth coefficients in the corresponding evolution equation. A strong, in the probabilistic sense, solution of the equation is constructed using Wiener Chaos expansion, and the properties of the solution are studied. Among the results obtained...

A genetic algorithm particle pairing technique for 3D velocity field extraction in holographic particle image velocimetry

This research explores a novel technique, using Genetic Algorithm Particle Pairing (GAPP) to extract threedimensional (3D) velocity fields of complex flows. It is motivated by Holographic Particle Image Velocimetry (HPIV), in which intrinsic speckle noise hinders the achievement of high particle density required for conventional correlation methods in extracting 3D velocity fields, especially i...

Micro-particle image velocimetry for velocity profile measurements of micro blood flows.

Micro-particle image velocimetry (μPIV) is used to visualize paired images of micro particles seeded in blood flows. The images are cross-correlated to give an accurate velocity profile. A protocol is presented for μPIV measurements of blood flows in microchannels. At the scale of the microcirculation, blood cannot be considered a homogeneous fluid, as it is a suspension of flexible particles s...