Download or read book The Development of Advanced Techniques for Particle Tracking Velocimetry written by Joseph Alan Duncan and published by . This book was released on 2009 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particle Image Velocimetry written by Markus Raffel and published by Springer. This book was released on 2018-04-03 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt: This immensely practical guide to PIV provides a condensed, yet exhaustive guide to most of the information needed for experiments employing the technique. This second edition has updated chapters on the principles and extra information on microscopic, high-speed and three component measurements as well as a description of advanced evaluation techniques. What’s more, the huge increase in the range of possible applications has been taken into account as the chapter describing these applications of the PIV technique has been expanded.
Download or read book Particle Tracking Velocimetry written by Dana Dabiri and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle velocimetry is a non-intrusive optical measurement method whereby global velocity fields can be obtained in either two- or three-dimensions through time by inferring fluid motion through the displacement of particle tracers which seed the flow. While particle image velocimetry (PIV), which obtains each velocity vector by tracking groups of particles within an interrogation window through a cross-correlation algorithm, has thrived generously since its development, particle tracking velocimetry (PTV), which obtains each of the velocity vector by tracking individual particle, has received less attention. The goal of this book is to therefore provide a review of PTV, with a focus on methods and techniques that have been implemented towards its development and improvement, rather than on its applications.
Download or read book Particle Tracking Velocimetry written by Dana Dabiri and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle velocimetry is a non-intrusive optical measurement method whereby global velocity fields can be obtained in either two- or three-dimensions through time by inferring fluid motion through the displacement of particle tracers which seed the flow. While particle image velocimetry (PIV), which obtains each velocity vector by tracking groups of particles within an interrogation window through a cross-correlation algorithm, has thrived generously since its development, particle tracking velocimetry (PTV), which obtains each of the velocity vector by tracking individual particle, has received less attention. The goal of this book is to therefore provide a review of PTV, with a focus on methods and techniques that have been implemented towards its development and improvement, rather than on its applications.
Download or read book Development of a Vision based Particle Tracking Velocimetry Method and Post processing of Scattered Velocity Data written by Micah Philip Paul and published by . This book was released on 2012 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a new vision-based hybrid particle tracking velocimetry (VB-PTV) technique is described and methods of processing randomly scattered velocity data investigated. The VB-PTV technique uses a feature matching method from computer vision theory which relies on the principles of proximity, similarity, and exclusion, meaning that it seeks to match one feature to one feature in subsequent images, and it favors matches which are close to one another and "look" similar. By constructing a matrix which takes these principles into account and performing singular value decomposition, a straightforward method of matching is developed which can give accurate matching results in a wide variety of flows. PIV velocity information is used to provide guidance to the matching algorithm. In addition, matches are made iteratively and validated by an outlier detection scheme. When this method is tested on synthetic images it results in matches which are typically reliable more than 98% of the time. A simple modification to the principle of proximity is introduced which reduces the PTV method's errors in highly shearing flow, as well as improving performance in general for various flow types. Finally, a natural neighbor-based interpolation technique is investigated for use in estimating flow derivatives using scattered velocity data. This interpolation method is compared with other existing techniques in terms of accuracy, sensitivity to noise, computational efficiency, and spatial resolution. It is found that the natural neighbor interpolation is less accurate than RBF and kriging interpolation methods, and more sensitive to noise, despite the use of a denoising technique.
Download or read book Particle Image Velocimetry written by Markus Raffel and published by Springer Science & Business Media. This book was released on 2007-08-09 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: This immensely practical guide to PIV provides a condensed, yet exhaustive guide to most of the information needed for experiments employing the technique. This second edition has updated chapters on the principles and extra information on microscopic, high-speed and three component measurements as well as a description of advanced evaluation techniques. What’s more, the huge increase in the range of possible applications has been taken into account as the chapter describing these applications of the PIV technique has been expanded.
Download or read book Particle Image Velocimetry written by Ronald J. Adrian and published by Cambridge University Press. This book was released on 2011 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle image velocimetry, or PIV, refers to a class of methods used in experimental fluid mechanics to determine instantaneous fields of the vector velocity by measuring the displacements of numerous fine particles that accurately follow the motion of the fluid. Although the concept of measuring particle displacements is simple in essence, the factors that need to be addressed to design and implement PIV systems that achieve reliable, accurate, and fast measurements and to interpret the results are surprisingly numerous. The aim of this book is to analyze and explain them comprehensively.
Download or read book 3 D Particle Tracking Velocimetry written by Wei-Hsin Tien and published by . This book was released on 2013 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis contains two parts of studies. In part I, a novel volumetric velocimetry technique is developed to measure the 3-D flow field of small-scale flows. The technique utilizes a color-coded pinhole plate with multiple light sources aligned to each pinhole to achieve high particle image density and large measurable depth on a single lens microscope system. A color separation algorithm and an improved particle identification algorithm are developed to identify individual particle images from each pinhole view. Furthermore, a calibration-based technique based on epi-polar line search method is developed to reconstruct the spatial coordinates of the particle, and a new two-frame tracking particle-tracking algorithm is developed to calculate the velocity field. The system was setup to achieve a magnification of 2.69, resulting in an imaging volume of 3.35 x 2.5 x 1.5 mm3 and showed satisfactory measurement accuracy. The technique was then further miniaturized to achieve a magnification of 10, resulting in a imaging volume of 600 x 600 x 600 μm3. The system was applied to a backward-facing step flow to test its ability to reconstruct the unsteady flow field with two-frame tracking. Finally, this technique was applied to a steady streaming flow field in a microfluidic device used to trap particles. The results revealed the three-dimensional flow structure that has not been observed in previous studies, and provided insights to the design of a more efficient trapping device. In part II, an in-vitro study was carried out to investigate the flow around a prosthetic venous valve. Using 2-D PIV, the dynamics of the valve motion was captured and the velocity fields were measured to investigate the effect of the sinus pocket and the coupling effect of a pair of valves. The PIV and hemodynamic results showed that the sinus pocket around the valve functioned as a flow regulator to smooth the entrained velocity profile and suppress the jet width. For current prosthetic valve design a shorter leaflets is advantageous because it prevents flow stasis and reduce the energy loss. Valve pairing tests showed that an orthogonal configuration of the valve pair result in a complicated 3-D flow around the valve, which can increase the mixing of the blood flow and prevent reversed flow in between the valves. The tests of different valve separation distance showed that the coupling effect of two valves was weakened as the separation distance increased, suggesting the existence of a separation distance between the two valves to maximize the coupling effect and keep the flow structure stable.
Download or read book Particle Identification Technique for Particle Tracking Velocimetry Application in Noiseless Image written by Yi-Lin Liu and published by . This book was released on 2021 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis will investigate particle identification in the 2D noiseless image. The modified cascade cross-correlation method (MCCM) is first introduced. The idea of it is to perform cross-correlation on images and apply a nonlinear least-square solver to give sub-pixel accuracy. Next is the support set method, which uses a morphological way to segment images. An iterative scheme is applied to each segment to acquire particle location. Finally, the technique developed from 3D tomographic PIV which is projected to 2D then utilizes nonnegative least-square (NNLS) to retrieve particle location. This method is superior in the ability to quantitatively find particles and the accuracy in constant particle size images. For images that the particle size varied, we proposed a method that required MCCM to determine the size to apply in NNLS and the result from NNLS to reconstruction image. After getting the reconstructed image, the residual can be calculated. The particle position corresponded to the lowest residual is selected to be the result that is shown better than other methods.
Download or read book Improvement to the Particle Tracking Velocimetry Method and is Application to the Study of the Development Region of a Shallow Turbulent Mixing Layer written by Javier Restrepo Grisales and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A methodology is proposed to reduce the error in the velocity estimation in Particle Tracking Velocimetry (PTV) for the study of the developing region of a turbulent shallow mixing layer. First, errors in velocity estimation can be reduced by improving the accuracy of the particle centre estimation by maximizing the spatial resolution of the image, with the constraint that it must contain the mixing layer. As the extent of the mixing layer is a function of its free stream velocity, channel width, and depth, the horizontal projection of mixing layers with 31 different combinations of flow parameters (width, depth, and free stream velocities) are studied to develop a model to predict the mixing layer extent as a function of the flow parameters. Secondly, an enhanced particle linking algorithm is proposed to avoid establishing incorrect particle trajectories representing atypical particle displacements. The algorithm uses an ellipsoid search region that varies in space and whose size is a function of the velocity at the position of the particle. The ellipsoid dimension is defined based on the ellipsoid confidence interval containing 99.75% of the velocity at the position of the particle. The velocity field at the surface of the mixing layer is measured using the PTV technique, and the mean, the root mean square, and the gradients of the velocity are analysed to understand the horizontal flow dynamics of the developing region of the shallow mixing layer. In addition, the vertical variation of the velocity is studied, using 3-D PTV, to characterize the vertical nonuniformity of the velocity of the developing mixing layer, and its consequence for particle dispersion"--
Download or read book The Particle Image Velocimetry written by Giovanna Cavazzini and published by BoD – Books on Demand. This book was released on 2012-05-23 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Particle Image Velocimetry is undoubtedly one of the most important technique in Fluid-dynamics since it allows to obtain a direct and instantaneous visualization of the flow field in a non-intrusive way. This innovative technique spreads in a wide number of research fields, from aerodynamics to medicine, from biology to turbulence researches, from aerodynamics to combustion processes. The book is aimed at presenting the PIV technique and its wide range of possible applications so as to provide a reference for researchers who intended to exploit this innovative technique in their research fields. Several aspects and possible problems in the analysis of large- and micro-scale turbulent phenomena, two-phase flows and polymer melts, combustion processes and turbo-machinery flow fields, internal waves and river/ocean flows were considered.
Download or read book Software Development for Particle Tracking Velocimetry written by Ayman Bargas Hatem and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A New Colored Method for Particle Tracking Velocimetry written by J. Stefanini and published by . This book was released on 1992 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditionally, the P.T.V techniques use a camera to record the displacement of the particles. Then, it is necessary to develop the negative film in order to digitize the images. In this paper, we present a now P.T.V method which is based on colored pulses and a color video camera (3 CCD camera). The particles images are digitizing in real time with a resolution of 24 bits and an image processing software allows to obtain the velocities field. After describing the experimental procedure, some results are presented on a water sock-up. (Author).
Download or read book Particle Image Velocimetry written by Michel Stanislas and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aeronautics industry is presently aiming for faster design cycles and shorter time to market of new aircraft. It is looking at the same time for improved aerodynamic performance, for evident competitive reasons. Advanced, computer based design systems, including fast and reliable numerical flow solvers, have been developed in the last decade including new turbulence models. On the experimental side, measurement techniques in general have also been improved significantly, however the data evaluation process remains still very time consuming, and unsteady effects and turbulence are often not being captured with sufficient accuracy and detail. The development of Particle Image Velocimetry (PIV) has helped to improve the analysis of the flow fields. After investigations in laboratory scale wind tunnels, a joint initiative on PIV research, by the European Aerospace Research Establishments, within GARTEUR have enabled a wide breakthrough of this new technology in Europe. Within the Research Framework Program of the European Union, the joint research project EUROPIV aimed to apply PIV technology to problems of industrial interest.
Download or read book New methods for particle image velocimetry and particle tracking velocimetry written by J. D. Cohen Khallas and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals and Applications of N pulse Particle Image Velocimetry accelerometry written by Liuyang Ding and published by . This book was released on 2018 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past three decades, particle image velocimetry (PIV) has been continuously growing to become an informative and robust experimental tool for fluid mechanics research. Compared to the early stage of PIV development, the dynamic range of PIV has been improved by about an order of magnitude (Adrian, 2005; Westerweel et al., 2013). Further improvement requires a breakthrough innovation, which constitutes the main motivation of this dissertation. N-pulse particle image velocimetry-accelerometry (N-pulse PIVA, where N>=3) is a promising technique to this regard. It employs bursts of N pulses to gain advantages in both spatial and temporal resolution. The performance improvement by N-pulse PIVA is studied using particle tracking (i.e. N-pulse PTVA), and it is shown that an enhancement of at least another order of magnitude is achievable. Furthermore, the capability of N-pulse PIVA to measure unsteady acceleration and force is demonstrated in the context of an oscillating cylinder interacting with surrounding fluid. The cylinder motion, the fluid velocity and acceleration, and the fluid force exerted on the cylinder are successfully measured. On the other hand, a key issue of multi-camera registration for the implementation of N-pulse PIVA is addressed with an accuracy of 0.001 pixel. Subsequently, two applications of N-pulse PTVA to complex flows and turbulence are presented. A novel 8-pulse PTVA analysis was developed and validated to accurately resolve particle unsteady drag in post-shock flows. It is found that the particle drag is substantially elevated from the standard drag due to flow unsteadiness, and a new drag correlation incorporating particle Reynolds number and unsteadiness is desired upon removal of the uncertainty arising from non-uniform particle size. Next, the estimation of turbulence statistics utilizes the ensemble average of 4-pulse PTV data within a small domain of an optimally determined size. The estimation of mean velocity, mean velocity gradient and isotropic dissipation rate are presented and discussed by means of synthetic turbulence, as well as a tomographic measurement of turbulent boundary layer. The results indicate the superior capability of the N-pulse PTV based method to extract high-spatial-resolution high-accuracy turbulence statistics.
Download or read book Development of Stereoscopic Particle Tracking Velocimetry for Turbulent Flow Field Diagnostics written by P. Veera Rajendran and published by . This book was released on 1993 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
