Experimental Investigation of the Internal Flow Field of a Model Gasoline Injector Using Micro-Particle Image Velocimetry

2006 ◽  
Author(s):  
P.G. Aleiferis ◽  
Y. Hardalupas ◽  
D. Kolokotronis ◽  
A.M.K.P. Taylor ◽  
A. Arioka ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Particle Image Velocimetry ◽  
Flow Field ◽  
Particle Image ◽  
Internal Flow ◽  
Micro Particle Image Velocimetry ◽  
Image Velocimetry

scholarly journals Experimental study on fiber suspensions in a curved expansion duct with particle image velocimetry

2012 ◽  
Vol 16 (5) ◽  
pp. 1414-1418 ◽  
Author(s):  
Xiao-Yu Liang ◽  
Huan-Huan Wu ◽  
Cheng-Xu Tu ◽  
Kai Zhang
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Flow Rate ◽  
Particle Image ◽  
Flow Direction ◽  
Internal Flow ◽  
Concave Wall ◽  
Image Velocimetry ◽  
Inlet Flow Rate ◽  
Convex Wall

The visualization measurement of internal flow field in a curved expansion duct is experimentally studied using particle image velocimetry technology and the influence of flow rate on flow field is analyzed. The streamline distribution and related performance curve in the internal flow field can be figured out through further analysis of experiment data. The results show that fiber orientation is mainly affected by velocity gradient, the fibers near the wall are aligned with the flow direction more quickly than the fibers in intermediate region, and the fibers near the concave wall are more quickly aligned with the flow direction than the convex wall. The larger inlet flow rate which will accordingly lead to increase inlet velocity enables the more quick adaptation and steady of fibers in flow direction.

Entrance Length Characteristics in Microchannels Using Micro-Particle Image Velocimetry

2007 ◽  
Author(s):  
Tariq Ahmad ◽  
Ibrahim Hassan ◽  
Roland Muwanga
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Particle Image ◽  
Working Fluid ◽  
Entrance Length ◽  
Number Range ◽  
Micro Particle Image Velocimetry ◽  
Micro Piv ◽  
Aspect Ratios ◽  
Image Velocimetry

An experimental study has been carried out to explore the laminar hydrodynamic development length in the entrance region of adiabatic square microchannels. Flow field measurements are acquired through the use of micro-Particle Image Velocimetry (micro-PIV), a non-intrusive particle tracking and flow observation technique. With the application of micro-PIV, entrance length flow field data is obtained for two different microchannel hydraulic diameters of 500 μm and 100 μm, both of which have cross-sectional aspect ratios of one. The working fluid is distilled water, and velocity profile data is acquired over a laminar Reynolds number range from 0 to 200. The test sections were designed as to provide a sharpedged microchannel inlet from an infinitely sized reservoir, at least 100 times wider and higher than the microchannel hydraulic diameter. Also, all microchannels have a length-to-diameter ratio of at least 100, to assure fully developed flow at the channel exit. The micro-PIV procedure is validated in the fully developed region with comparison to Navier-Stokes momentum equations. Good agreement was found with comparison to conventional entrance length correlations for ducts, and no influence of scaling was observed.

scholarly journals Shrinking instability of toroidal droplets

2017 ◽  
Vol 114 (11) ◽  
pp. 2871-2875 ◽  
Author(s):  
Alexandros A. Fragkopoulos ◽  
Ekapop Pairam ◽  
Eric Berger ◽  
Phil N. Segre ◽  
Alberto Fernández-Nieves
Keyword(s):  
Surface Tension ◽  
Particle Image Velocimetry ◽  
Flow Field ◽  
Cross Section ◽  
Particle Image ◽  
Internal Flow ◽  
Experimental Results ◽  
Image Velocimetry ◽  
The Many

Toroidal droplets are inherently unstable due to surface tension. They can break up, similar to cylindrical jets, but also exhibit a shrinking instability, which is inherent to the toroidal shape. We investigate the evolution of shrinking toroidal droplets using particle image velocimetry. We obtain the flow field inside the droplets and show that as the torus evolves, its cross-section significantly deviates from circular. We then use the experimentally obtained velocities at the torus interface to theoretically reconstruct the internal flow field. Our calculation correctly describes the experimental results and elucidates the role of those modes that, among the many possible ones, are required to capture all of the relevant experimental features.

Flow Field Measurements Near a Moving Meniscus of a Capillary Flow With Micro Particle Image Velocimetry (µPIV)

2008 ◽  
Author(s):  
Ralph Nasarek ◽  
Steve Wereley ◽  
Peter Stephan
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Flow Pattern ◽  
Contact Line ◽  
Particle Image ◽  
Field Measurements ◽  
Phase Contact ◽  
Micro Particle Image Velocimetry ◽  
Image Velocimetry ◽  
Three Phase

Due to the relevance of capillary flows for industrial applications, the dynamics of menisci have been extensively investigated. Contrary to the meniscus velocity, the flow pattern near the meniscus is rather unexplored. The main focus of this study is the visualization of the flow field near the fast moving meniscus with micro particle image velocimetry (μPIV). Therefore an invasive flow of ethanol in a vertical cylindrical glass tube is investigated. The entrance of the tube is located inside a reservoir with a rising liquid surface. Especially near the tube entrance the flow is high dynamical (ca. 120 mm/s) which necessitates high temporal resolution measurement techniques. Flow field measurements at several positions in flow direction have been conducted to compare the meniscus shape and the flow fields near the three phase contact line. The flow pattern near the meniscus is extremely complex. While the typical Hagen-Poiseuille profile with no radial velocity component is to be found far from the meniscus, the flow near the meniscus cannot be a convex velocity profile. As a matter of fact the meniscus movement is characterized by adsorption of the liquid near the wall and liquid transport from the middle of the flow to the three phase contact line. This special flow pattern has been examined. Furthermore it was found that the shape of the meniscus varies over the whole invasion of the tube. The curvature of the meniscus and therefore the contact angle between solid and liquid are getting smaller over the infiltration length which has influence on the capillary force. Measurements near the entrance of the tube show an acceleration of the liquid column until it reaches a certain speed and after that a deceleration. To determine the velocity of the raising meniscus, global measurements of the whole tube have been performed.

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