
	Where results make sense

Topic: Particle image velocimetry

Related Topics

List of bands with names consisting entirely of integers

Combustion

Eanfrith

List of Lords of Appeal in Ordinary

Canadian Learning Television

In the News (Sun 15 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Development of Particle Image Velocimetry Techniques for Measurement of Room Airflow Patterns in Ventilated Airspaces
		High-image- density PIV was established as an improvement mode of LSV to overcome the high-density particle seeding difficulty in practical situations by Pickering and Halliwell (1984) and Adrian (1984).
		Image of particles visualized in the light sheet are recorded as streaks using the photographic camera moving at constant shift speed.
		The diameter of a particle image is determined by the diameter of the particle, the magnification, and the point diffusion of the lens.
	www.age.uiuc.edu /bee/Research/piv/Pivpaper2.htm (5311 words)

	Particle image velocimetry - Wikipedia, the free encyclopedia
		Particle Image velocimetry (PIV) is an optical method used to measure velocities and related properties in fluids.
		The fluid is seeded with particles, which, for the purposes of PIV, are generally assumed to faithfully follow the flow dynamics.
		Typical PIV apparatus consists of a camera (normally a digital camera in modern systems), a high power laser, for example a double-pulsed Nd-YAG laser laser or a copper vapour laser, an optical arrangement to convert the laser output light to a light sheet (normally using a cylindrical lens), and the fluid/gas under investigation.
	en.wikipedia.org /wiki/Particle_Image_Velocimetry (1046 words)

	Flow Over a Circular Cylinder
		particle pathline visualization sequence, there are alternative upward and downward flows in the wake as the result of vortex shedding.
		The PIV is a quantitative flow visualization technique, which can be used to determine the instantaneous whole-field fluid velocities by recording and processing the multiply-exposed particle image pattern of small traces suspended in the fluid.
		The PIV particle image is first obtained by illuminating the seeded flow field with a thin laser sheet.
	www.eng.fsu.edu /~shih/succeed/cylinder/cylinder.htm (1582 words)

	bloodapp
		In PIV, two successive images are captured, and the particles in one image correlated with the particles in the next.
		At typical flow velocities, the particles would move too far to track from one image to the next — in essence, PIV with such a laser would be a single-point method.
		Digital particle image velocimetry experiments such as the ones underway at the University of California, Berkeley are crucial to understanding blood flows.
	www.new-wave.com /1nwrProducts/PIVbloodApp.htm (954 words)

	Dantec. Principles of Particle Image Velocimetry (Site not responding. Last check: 2007-10-30)
		Particle Image Velocimetry (PIV) is a whole-flow-field technique providing instantaneous velocity vector measurements in a cross-section of a flow.
		In PIV, the velocity vectors are derived from sub-sections of the target area of the particle-seeded flow by measur-ing the movement of particles between two light pulses:
		The number of particles in the flow is of some importance in obtaining a good signal peak in the cross-correlation.
	www.dantecdynamics.com /PIV/Princip/Index.html (639 words)

	Particle Image Velocimetry (PIV) Systems
		Particle Image Velocimetry (PIV) is a very common and useful tool to investigate the flow phenomena in models of blood vessels, heart valves or artificial organs.
		After recording the images are stored to the hard disk drive of a PC and can be analyzed using the cross correlation technique.
		A gray value analysis with a special image processing program permits to determine this distance, which is necessary for the calculation of the wall shear stress.
	www.charite.de /biofluidmechanik/gb/forschung/piv_GB_0.html (440 words)

	particle detector - Hutchinson encyclopedia article about particle detector (Site not responding. Last check: 2007-10-30)
		One of a number of instruments designed to detect subatomic particles and track their paths; they include the cloud chamber, bubble chamber, spark chamber, and multiwire chamber.
		The earliest particle detector was the cloud chamber, which contains a super-saturated vapour in which particles leave a trail of droplets, in much the same way that a jet aircraft leaves a trail of vapour in the sky.
		As a particle passes through the chamber, it produces an electrical signal in the wires.
	encyclopedia.farlex.com /Particle+detector (253 words)

	PIV: Particle Image Velocimetry
		The displacement of the particle images is measured in the plane of the image and used to determine the displacement of the particles in the flow.
		The spatial displacement that produces the maximum cross-correlation statistically approximates the average displacement of the particles in the interrogation cell.
		Typically, the PIV measures on a 100 x 100 grid with accuracy between 0.2% and 5% of full scale and spatial resolution ~1mm.
	www.efluids.com /efluids/pages/products/piv.htm (289 words)

	Forward-Scattering Particle-Image Velocimetry
		Unlike other PIV techniques, (1) particles are back-illuminated with coherent or partially coherent light, (2) a microscope is used to resolve forward scattering of light from the particles, and (3) all three components of velocity can be measured from only one line of sight, without readjustment of optics.
		Forward-scattered light from a particle in the field of view of the microscope is brought to focus on the microscope image plane to obtain a magnified image of the particle.
		The scattering pattern for each particle is analyzed to determine the distance of the particle, relative to the focal plane, along the line of sight.
	www.nasatech.com /Briefs/Dec99/LEW16403.html (646 words)

	Digital particle image velocimetry
		Digital Particle Image Velocimetry (DPIV) is a method I have employed for visualizing water flow in the wake of freely swimming fishes.
		The technique involves seeding the water in a flow tank with reflective neutrally buoyant particles and illuminating the particles with a laser which is focused into a thin sheet of light.
		Camera 2 and a mirror within the flow downstream are used to film the posterior perspective of the fish, which is helpful for showing the position of the laser plane relative to the fish's fin.
	darwin.bio.uci.edu /~edrucker/home/dpiv.htm (519 words)

	Digital Particle Image Velocimetry
		Once the spatially displaced images are stored in two separate frames, each velocity vector is extracted by performing mathematical correlation analysis on a cluster of particles within each interrogation region between the two frames (eliminating the problem of directional ambiguity).
		The PIV interrogation process is repeated until all the required velocity information is extracted from the captured record.
		In general terms, particle image velocimetry (PIV) is the low particle concentration equivalent of Laser Speckle Velocimetry (LSV) and developed from speckle interferometry which is used to measure surface displacements in solid mechanics.
	www.holomap.com /dpiv.htm (538 words)

	PIV, particle image velocimetry, camera (Site not responding. Last check: 2007-10-30)
		In such studies, the water-phase of the flow field is seeded with fluorescent particles to give an orange signal, with the bubbles emitting the green signal of the illuminating laser light.
		Image, lens and object plane must cross each other along a common line in space for the camera images to be accurately focused.
		If the initial positions of seeding particles are sampled on a different camera frame from the final positions then the velocity direction is inherently known since it is known which is the first and second frame of the camera.
	www.dantecmt.com /piv/system/acquisition/Index.html (1271 words)

	Session Cj - Experimental Techniques.
		Particles are illuminated by a continuously emitting Mercury arc lamp or by a pulsed Nd:YAG laser.
		Particle Image Velocimetry (PIV) is becoming a well established experimental technique to measure two components of the velocity in a planar region of a flow field.
		Using PIV in conjunction with the photographic method commonly referred to as the Scheimpflug condition, it is possible to focus on a plane in space from an oblique angle.
	flux.aps.org /meetings/YR97/BAPSDFD97/abs/S3000.html (1505 words)

	Particle Image Velocimetry
		The option is restricted to a smaller variety of methods for determining the optimal shift between the images, utilising either the absolute difference, the square of the difference between the two images, or the cross-correlation function.
		The image difference is evaluated by the ALU for a specified range of shifts to build up a data base describing how the difference image varies with the shift, while the cross-correlation is evaluated by the CPU (and hence is significantly slower).
		The response to this prompt specifies the buffer containing the image to be used as the base image for the optimal shift.
	www.damtp.cam.ac.uk /user/fdl/people/sd/digimage/hlpfiles/lp.htm (1374 words)

	Large-Scale Particle Image Veloc (Site not responding. Last check: 2007-10-30)
		Large-scale particle image velocimetry (LSPIV) is an extension of conventional PIV for velocity measurements in large-scale flows (Fujita et al., 1998).
		While the image- and data-processing algorithms are similar to those used in conventional PIV, adjustments are required for illumination, seeding, and pre-processing of the recorded images.
		Transformation of the images to remove perspective distortion as well as the subsequent image processing were conducted on a PC using in-house developed software (Fujita et al., 1998).
	www.iihr.uiowa.edu /facilities/Velocimentry_files/Velocimentry.html (580 words)

	Dusty Plasma - Particle Image Velocimetry (PIV) (Site not responding. Last check: 2007-10-30)
		The Particle Image Velocimetry (PIV) system is used to make direct, two-dimensional measurement of the dust particle velocities in the dusty plasma.
		In the PIV technique, two laser pulses (one each from a pair of frequency-doubled 25 mJ, Nd-YAG lasers) are expanded into a 2-D "sheet" by a 50 mm cylindrical lens.
		As compared to other velocimetry techniques (e.g., laser doppler velocimetry) which measure one particle at a time, PIV is a volumetric measurement...
	www.physics.auburn.edu /~plasma/basic/dusty/dusty_piv.html (254 words)

	Micron Resolution Particle Image Velocimetry (Site not responding. Last check: 2007-10-30)
		The particles are assumed to follow the fluid motion as well as not significantly change the fluid properties (eg.
		This pair of images is then loaded into a commercially available software package which has the ability to perform a mathematical technique known as a "correlation".
		The correlation algorithm, when applied to the pair of images, returns the mean displacement of the particles between the two exposures.
	www.engineering.ucsb.edu /~barkus/micro_piv.html (402 words)

	Large-scale structures forming in a cross flow: Particle Image Velocimetry Conditional Analysis (ResearchIndex) (Site not responding. Last check: 2007-10-30)
		Abstract: A conditional Particle Image Velocimetry acquisition technique and averaging procedure are developed to study coherent structures formed by the interaction between a jet and a cross-stream.
		Particle Image Velcimetry and Thermometry in Freezing Water - Kowalewski, al.
		Particle Image Velocimetry Using Optical Flow For Image..
	citeseer.ist.psu.edu /518238.html (391 words)

	Dual-Plane Particle Image Velocimetry (Site not responding. Last check: 2007-10-30)
		Dual-Plane PIV was implemented to enable the measurement of all three velocity components of a breaking wave.
		This technique involves recording three images of tracer particles within the fluid, two in the original plane of the lightsheet, and a third in a displaced lightsheet.
		The 4-camera system could produce a total of 120 images per second, or the individual cameras could be triggered in quick succession to record high-speed events.
	www.ph.ed.ac.uk /~ted/thesis/node125.html (238 words)

	Particle Image Velocimetry... Abstract
		Particle image velocimetry; a new technique to measure strain in loaded snow.
		The displacement caused by the loading was calculated using particle image velocimetry (PIV) in which particle paths are traced with a rapid sequence of digital photographs.
		The medium must be seeded with tracer particles in order for the software to follow the reflected light of each tracer particle as it moves under a band load.
	geosurvey.state.co.us /Default.aspx?tabid=293 (312 words)

	PARTICLE IMAGE (Site not responding. Last check: 2007-10-30)
		Recently, two-dimensional (2D) video-based particle image velocimetry (PJV) has been applied to the nearshore region and compared favorably to other video-based horizontal velocity estimations (timestack method) in the swash zone.
		PIV is appealing because it is a non-intrusive, cost-effective method yielding dense 2D horizontal surface velocity estimates over a large spatial region.
		This study aims to further validate the PIV technique through a field experiment conducted at Scripps Beach in La Jolla, CA by comparing PIV surface velocity vectors with those obtained from the timestack method and several ADV's deployed across the swash zone.
	www7440.nrlssc.navy.mil /particle%20image.htm (277 words)

	Holographic Particle Image Velocimetry
		In Holographic Particle Image Velocimetry (HPIV), the position of all the particles present at one instant of time is recorded on a holographic plate (double-exposure).
		The light scattered from the particle (~1 - 50 microns (in air)) is made to interfere with the reference laser beam and the interference effect is then recorded locally onto the holographic plate.
		This avoids problems of magnification and poor image contrast in the holographic records. Recently, the HPIV technique (side-scattered, reflection geometry) has been demonstrated successfully in an optical internal combustion engine.
	www.holomap.com /hpiv.htm (367 words)

	Planar Particle Imaging Doppler Velocimetry Developed
		In the standard PIV technique, a pulsed laser is used to illuminate the flow field at two closely spaced instances in time, which are recorded on a "frame-straddling" camera, yielding a pair of single-exposure image frames.
		The PIV camera is oriented perpendicular to the light sheet, and the processed PIV data yield the two-component velocity field in the plane of the light sheet.
		Taking the ratio of the intensity-modulated signal image to the reference image yields an intensity map that is proportional to the gas velocity in the plane of the light sheet.
	www.grc.nasa.gov /WWW/RT/2003/5000/5520wernet.html (635 words)

	URAPIV - where Matlab meets Particle Image Velocimetry
		As you will see in a minute, it is very simple, easily extendable from your standard stereoscopic PIV system and the only missing ingredients are a) high-energy cubic beamsplitters, b) rotational mount with a half-wave plate, c) some sophisticated image processing and d) know-how.
		It means that one has to rename the files to let Insight understand that these are the pair of images to correlate.
		We have applied PIV techniques to the study of complex (dusty) plasmas for a number of years and have two commercial PIV systems (a 2D system from TSI and a stereo system from LaVision).
	urapiv.wordpress.com (1307 words)

Try your search on: Qwika (all wikis)