Investigation of Field Amplified Sample Stacking With Particle Image Velocimetry

2002 ◽  
Author(s):  
Shankar Devasenathipathy ◽  
Rajiv Bharadwaj ◽  
Juan G. Santiago

This paper presents an experimental investigation of field amplified sample stacking (FASS) with micron resolution particle image velocimetry (μPIV). The preliminary experiments reported in this work show particle velocity fields in electrokinetic flow in a glass microchannel with a single buffer-buffer interface. The buffer-to-buffer conductivity ratio is 10. Stacking of latex microspheres (i.e., increases in their number density) in the presence of a background electroosmotic flow is demonstrated. The generation of an internal pressure gradient is quantified using μPIV. This work is part of an ongoing study of the spatial and temporal development of the velocity and concentration profiles of FASS systems.

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1205
Author(s):  
Ruiqi Wang ◽  
Riqiang Duan ◽  
Haijun Jia

This publication focuses on the experimental validation of film models by comparing constructed and experimental velocity fields based on model and elementary experimental data. The film experiment covers Kapitza numbers Ka = 278.8 and Ka = 4538.6, a Reynolds number range of 1.6–52, and disturbance frequencies of 0, 2, 5, and 7 Hz. Compared to previous publications, the applied methodology has boundary identification procedures that are more refined and provide additional adaptive particle image velocimetry (PIV) method access to synthetic particle images. The experimental method was validated with a comparison with experimental particle image velocimetry and planar laser induced fluorescence (PIV/PLIF) results, Nusselt’s theoretical prediction, and experimental particle tracking velocimetry (PTV) results of flat steady cases, and a good continuity equation reproduction of transient cases proves the method’s fidelity. The velocity fields are reconstructed based on different film flow model velocity profile assumptions such as experimental film thickness, flow rates, and their derivatives, providing a validation method of film model by comparison between reconstructed velocity experimental data and experimental velocity data. The comparison results show that the first-order weighted residual model (WRM) and regularized model (RM) are very similar, although they may fail to predict the velocity field in rapidly changing zones such as the front of the main hump and the first capillary wave troughs.


2002 ◽  
Vol 2 (5-6) ◽  
pp. 47-55
Author(s):  
N.-S. Park ◽  
H. Park

Recognizing the significance of factual velocity fields in a rapid mixer, this study focuses on analyzing local velocity gradients in various mixer geometries with particle image velocimetry (PIV) and comparing the results of the analysis with the conventional G-value, for reviewing the roles of G-value in the current design and operation practices. The results of this study clearly show that many arguments and doubts are possible about the scientific correctness of G-value, and its current use. This is because the G-value attempts to represent the turbulent and complicated factual velocity field in a jar. Also, the results suggest that it is still a good index for representing some aspects of mixing condition, at least, mixing intensity. However, it cannot represent the distribution of velocity gradients in a jar, which is an important factor for mixing. This study as a result suggests developing another index for representing the distribution to be used with the G-value.


2006 ◽  
Vol 508 ◽  
pp. 157-162 ◽  
Author(s):  
Sven Eck ◽  
J.P. Mogeritsch ◽  
Andreas Ludwig

3D samples of NH4Cl-H2O solutions were solidified under defined experimental conditions. The occurring melt convection was investigated by Particle Image Velocimetry (PIV). The occurrence of NH4Cl crystals was observed optically and first attempts were made to quantitatively measure its number density, size distribution and sedimentation rate by PIV and Particle Tracking (PT). In order to prove the reproducibility of the results several experimental runs with equal and slightly modified conditions were analyzed.


2021 ◽  
Vol 2127 (1) ◽  
pp. 012018
Author(s):  
S S Usmanova ◽  
N M Skornyakova ◽  
Yu S Belov ◽  
M V Sapronov ◽  
A V Kuchmenko ◽  
...  

Abstract The paper is devoted to development of the optical electronic setup for carrying out measurements by multicolor particle image velocimetry. The main advantage of this method is the ability to visualize vector velocity fields in several planes simultaneously. As a result a 3D model of a setup was developed, a laboratory sample was assembled and series of testing experiments were performed. As a test object, vortex structure formed by a chemical stirrer in a cuvette with liquid has been considered. The experimental data were compared with the computer model developed in SolidWorks and FlowVision software.


2006 ◽  
Author(s):  
Pranay Mahendra ◽  
Michael G. Olsen

Recently the automotive industry has been using superchargers to boost the power generated by the engine, but the noise generated by these superchargers is of great concern. The noise generated during the working of the supercharger is primarily a fluid mechanics phenomenon. Particle Image Velocimetry (PIV) was used to study air flow characteristics of a positive displacement supercharger with an emphasis on gaining insights into strategies for noise reduction. PIV was used to measure the instantaneous and ensemble-averaged velocity fields of the flow at the outlet of the supercharger as a function of blade position, allowing for visualization of the flow as it leave the blades. The preliminary results show that the flow exits the supercharger as a high speed jet at the end closer to the pulley end, and the flow varies with the change in blade position.


2000 ◽  
Author(s):  
Shankar Devasenathipathy ◽  
Joshua I. Molho ◽  
James C. Mikkelsen ◽  
Juan G. Santiago ◽  
Kohsei Takehara

Abstract A micron-resolution particle image velocimetry (PIV) system has been developed to spatially and temporally resolve electroosmotic flow fields within microfluidic bioanalytical devices. A second diagnostic technique, particle tracking velocimetry (PTV) has been used to determine the distribution of electrophoretic mobilities of seed particles and thereby make the PIV measurements quantitative. This second particle tracking technique has been used to determine probability distribution functions of the seed particles. Results from simulations of electric fields yield local electric field strengths in the geometries of interest. The measured mean mobility of the seed particles (obtained from PTV measurements) is then multiplied by the local electric field vector to obtain the electrophoretic velocity. The variance on the particle mobility measurement influences the errors introduced in the electroosmotic flow measurements. After total particle velocities are measured within a microfluidic system of interest, the seed particle electrophoretic velocities are subtracted from the PIV total velocity data to obtain electroosmotic flow field velocities. Ensemble-averaged velocity field measurements for electroosmotic flow at the intersection of a cross-channel are presented.


2013 ◽  
Vol 8 (4) ◽  
pp. 110-117
Author(s):  
Konstantin Dobroselsky

Experimental setup (hydrodynamic pipe) for the study of turbulent flows has been upgraded. Test experiments with a cross-flow around a cylinder have been carried out. Using the method of flow visualization PIV (Particle Image Velocimetry) the velocity fields around the cylinder for precavitational and cavitation regimes (Re = 2,8 · 105 ) have been obtained


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