Journal ArticleDOI
Pulsed laser technique application to liquid and gaseous flows and the scattering power of seed materials
Ronald J. Adrian,Chung Sheng Yao +1 more
TLDR
From computations the smallest particles that can be photographed in various fluid measurement situations, including air and water, have been determined in terms of system parameters such as laser power, light sheet geometry, f/No.Abstract:
Mie scattering computations have been performed for light scattered by small particles from a pulsed sheet of laser illumination and collected and imaged by a camera lens. From these computations the smallest particles that can be photographed in various fluid measurement situations, including air and water, have been determined in terms of system parameters such as laser power, light sheet geometry, f/No., and photographic film properties. The particle scattering requirements of the individual particle image mode and the speckle mode are compared.read more
Citations
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Journal ArticleDOI
A PIV Algorithm for Estimating Time-Averaged Velocity Fields
TL;DR: In this paper, a PIV algorithm is presented for estimating time-averaged or phaseaveraged velocity fields, which can be applied to situations where signal strength is not sufficient for standard cross correlation techniques, such as a low number of particle images in an interrogation spot, or poor image quality.
Journal ArticleDOI
Volume illumination for two-dimensional particle image velocimetry
TL;DR: In this article, a theoretical expression for the depth of the two-dimensional measurement plane is derived and it is shown that the particle concentration must be chosen judiciously in order to balance the desired spatial resolution and signal-to-noise ratio of the particle-image field.
Book ChapterDOI
Digital Particle Image Velocimetry
TL;DR: The first non-invasive point velocity measurement technique was Laser Doppler Velocimetry (LDV), which used a crossed pair of laser beams to measure the velocity of seed particles entrained in the flow as discussed by the authors.
Journal ArticleDOI
Micro-Particle Image Velocimetry (microPIV): recent developments, applications, and guidelines.
TL;DR: This review discusses the state of the art of the optical whole-field velocity measurement technique micro-scale Particle Image Velocimetry (microPIV), a useful tool for fundamental research of microfluidic applications in life science, lab-on-a-chip, biomedical research, micro chemical engineering, analytical chemistry and other related fields of research.
Journal ArticleDOI
Particle image velocimetry: A review
TL;DR: The evolution of particle image velocimetry (PIV) from its various roots is discussed in this paper, where the importance of these roots and their influence on different trends in the speciality are described.
References
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ReportDOI
Statistical properties of laser sparkle patterns
TL;DR: In this article, the first order statistics of the observed electric-field strength, the observed light intensity, and observed light phase are examined, and the autocorrelation functions of the complex field and intensity processes are investigated, and that of the electric field is found to be proportional to the Fourier transform of the light intensity distribution incident on the scattering surface.
Book ChapterDOI
Statistical Properties of Laser Speckle Patterns
TL;DR: In this article, the first-order statistics of the complex amplitude, intensity and phase of speckle are derived for a free-space propagation geometry and for an imaging geometry.
Journal ArticleDOI
Scattering particle characteristics and their effect on pulsed laser measurements of fluid flow: Speckle velocimetry vs particle image velocimetry
TL;DR: The source density for a fluid volume illuminated by a laser sheet of thickness Δz is defined to be the number density of particles per unit volume and their size can vary over a very wide range of values, depending upon the fluid and its treatment.
Journal ArticleDOI
Laser speckle photography in a fluid medium
T. D. Dudderar,P. G. Simpkins +1 more
TL;DR: In this article, a technique for obtaining quantitative velocity data from hydrodynamic flow fields using laser speckle photography (LSP) has been developed and uses the scattered light from the interior of a suitably seeded liquid which is illuminated by a coherent beam from a pulsed ruby laser.
Journal ArticleDOI
Measuring fluid velocities with speckle patterns
D B Barker,M E Fourney +1 more
TL;DR: A new full-field technique for mapping lines of constant velocity in a fluid flow is demonstrated and is used with the established methods of speckle photography and interferometry to determine the velocity field.