Measurement of temperature and velocity fields in a heater unit by liquid crystal thermometry and particle image velocimetry

2000 ◽  
Vol 3 (3) ◽  
pp. 267-274
Author(s):  
N. Fujisawa ◽  
H. Ikeda ◽  
R. Saito ◽  
M. Yokota
Keyword(s):  
Particle Image Velocimetry ◽  
Liquid Crystal ◽  
Particle Image ◽  
Velocity Fields ◽  
Image Velocimetry ◽  
Temperature And Velocity Fields

scholarly journals Experimental Validation of Falling Liquid Film Models: Velocity Assumption and Velocity Field Comparison

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1205
Author(s):  
Ruiqi Wang ◽  
Riqiang Duan ◽  
Haijun Jia
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Velocity Field ◽  
Experimental Validation ◽  
Particle Image ◽  
Velocity Fields ◽  
Number Range ◽  
Comparison Results ◽  
Image Velocimetry ◽  
Experimental Particle

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.

Analysis of local velocity gradients in rapid mixer using particle image velocimetry technique

2002 ◽  
Vol 2 (5-6) ◽  
pp. 47-55
Author(s):  
N.-S. Park ◽  
H. Park
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Velocity Fields ◽  
Local Velocity ◽  
Mixing Condition ◽  
Particle Image Velocimetry Technique ◽  
Velocity Gradients ◽  
Image Velocimetry ◽  
Current Design ◽  
G Value

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.

Investigation of Field Amplified Sample Stacking With Particle Image Velocimetry

2002 ◽  
Author(s):  
Shankar Devasenathipathy ◽  
Rajiv Bharadwaj ◽  
Juan G. Santiago
Keyword(s):  
Particle Image Velocimetry ◽  
Electroosmotic Flow ◽  
Particle Image ◽  
Velocity Fields ◽  
Concentration Profiles ◽  
Conductivity Ratio ◽  
Number Density ◽  
Electrokinetic Flow ◽  
Sample Stacking ◽  
Image Velocimetry

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.

Aerothermal Investigation of a Single Row Divergent Narrow Impingement Channel by Particle Image Velocimetry and Liquid Crystal Thermography

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Alexandros Terzis ◽  
Christoforos Skourides ◽  
Peter Ott ◽  
Jens von Wolfersdorf ◽  
Bernhard Weigand
Keyword(s):  
Heat Transfer ◽  
Particle Image Velocimetry ◽  
Liquid Crystal ◽  
Flow Field ◽  
Particle Image ◽  
Field Measurements ◽  
Single Row ◽  
Transient Techniques ◽  
Liquid Crystal Thermography ◽  
Image Velocimetry

Integrally cast turbine airfoils with wall-integrated cooling cavities are greatly applicable in modern turbines providing enhanced heat exchange capabilities compared to conventional cooling passages. In such arrangements, narrow impingement channels can be formed where the generated crossflow is an important design parameter for the achievement of the desired cooling efficiency. In this study, a regulation of the generated crossflow for a narrow impingement channel consisting of a single row of five inline jets is obtained by varying the width of the channel in the streamwise direction. A divergent impingement channel is therefore investigated and compared to a uniform channel of the same open area ratio. Flow field and wall heat transfer experiments are carried out at engine representative Reynolds numbers using particle image velocimetry (PIV) and liquid crystal thermography (LCT). The PIV measurements are taken at planes normal to the target wall along the centerline for each individual jet, providing quantitative flow visualization of jet and crossflow interactions. The heat transfer distributions on the target plate of the channels are evaluated with transient techniques and a multilayer of liquid crystals (LCs). Effects of channel divergence are investigated combining both the heat transfer and flow field measurements. The applicability of existing heat transfer correlations for uniform jet arrays to divergent geometries is also discussed.

scholarly journals Development of the optical electronic setup for carrying out measurements by multicolor Particle Image Velocimetry

2021 ◽  
Vol 2127 (1) ◽  
pp. 012018
Author(s):  
S S Usmanova ◽  
N M Skornyakova ◽  
Yu S Belov ◽  
M V Sapronov ◽  
A V Kuchmenko ◽  
...  
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Computer Model ◽  
Vortex Structure ◽  
Test Object ◽  
3D Model ◽  
Particle Image ◽  
Velocity Fields ◽  
Laboratory Sample ◽  
Image Velocimetry

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.

Unsteady Velocity Field Measurements of Outlet Flow in an Automotive Supercharger

2006 ◽  
Author(s):  
Pranay Mahendra ◽  
Michael G. Olsen
Keyword(s):  
Particle Image Velocimetry ◽  
Automotive Industry ◽  
High Speed ◽  
Particle Image ◽  
Flow Characteristics ◽  
Field Measurements ◽  
Velocity Fields ◽  
Positive Displacement ◽  
Image Velocimetry ◽  
Outlet Flow

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.

Research Methodology of Cross-Flow Cylinder Pipe Hydrodynamical

2013 ◽  
Vol 8 (4) ◽  
pp. 110-117
Author(s):  
Konstantin Dobroselsky
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Visualization ◽  
Turbulent Flows ◽  
Research Methodology ◽  
Particle Image ◽  
Cross Flow ◽  
Velocity Fields ◽  
Experimental Setup ◽  
Flow Around A Cylinder ◽  
Image Velocimetry

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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