Experimental Investigations Into Mixed Convection About a Horizontal Cylinder: Part B — Fluid Dynamics Using Particle Image Velocimetry

2005 ◽  
Author(s):  
Vanessa Egan ◽  
Tara Dalton ◽  
Mark R. D. Davies
Keyword(s):  
Particle Image Velocimetry ◽  
Fluid Flow ◽  
Flow Field ◽  
Mixed Convection ◽  
Particle Image ◽  
Reynolds Numbers ◽  
Experimental Investigations ◽  
Convection Flow ◽  
Flow Visualisation ◽  
Image Velocimetry

The second of two papers investigating mixed convection about a cylinder in the buoyancy opposing cross flow regime. The experimental configuration is essentially the same as that used in part A, [1]. Particle image velocimetry (PIV) is used to measure the fluid flow at Reynolds numbers in the range of 32 to 89 and Rayleigh numbers of 1.7E+04 and 2.4E+04. Fluid flow results are shown in the form of instantaneous vector plots with corresponding flow visualisation images, streamline plots and velocity vector plots. The presence of the opposing flow created an unsteady flow field about the cylinder at lower Reynolds numbers while increasing the Reynolds number resulted in the development of a steady flow field tending towards that of a forced convection flow. An increase in Rayleigh number led to an increase the instability of the flow field. The velocity field results were found to compliment the heat transfer investigation detailed in part A, [1].

scholarly journals Feasibility of Optical Flow Field Measurements of the Coolant in a Grinding Machine

2021 ◽  
Vol 11 (24) ◽  
pp. 11615
Author(s):  
Björn Espenhahn ◽  
Lukas Schumski ◽  
Christoph Vanselow ◽  
Dirk Stöbener ◽  
Daniel Meyer ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Fluid Flow ◽  
Flow Field ◽  
Optical Flow ◽  
Particle Image ◽  
Field Measurements ◽  
Optical Flow Field ◽  
Metalworking Fluid ◽  
Image Velocimetry ◽  
Grinding Machine

For industrial grinding processes, the workpiece cooling by metalworking fluids, which strongly influences the workpiece surface layer quality, is not yet fully understood. This leads to high efforts for the empirical determination of suitable cooling parameters, increasing the part manufacturing costs. To close the knowledge gap, a measurement method for the metalworking fluid flow field near the grinding wheel is desired. However, the varying curved surfaces of the liquid phase result in unpredictable light deflections and reflections, which impede optical flow measurements. In order to investigate the yet unknown optical measurement capabilities achievable under these conditions, shadowgraphy in combination with a pattern correlation technique and particle image velocimetry (PIV) are applied in a grinding machine. The results show that particle image velocimetry enables flow field measurements inside the laminar metalworking fluid jet, whereby the shadowgraph imaging velocimetry complements these measurements since it is in particular suitable for regions with spray-like flow regimes. As a conclusion, optical flow field measurements of the metalworking fluid flow in a running grinding machine are shown to be feasible.

Flow Field and Turbulence Characterization of a Counter Impinging Jet Reactor Using Particle Image Velocimetry

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Victor A. Miller ◽  
Mirko Gamba
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Reynolds Stress ◽  
Particle Image ◽  
Impinging Jet ◽  
Reynolds Numbers ◽  
Inlet Section ◽  
Turbulent Stress ◽  
Mean Flow ◽  
Image Velocimetry

We characterize the three dimensional structure and quantify turbulence quantities in a counter-impinging jet reactor with trapezoidal cross-section to test the feasibility of achieving stratified mixing. Dye flow-visualization and particle image velocimetry (PIV) velocity field measurements are made in the inlet section of the reactor. Two-component velocity measurements are made on three sets of orthogonal planes for Rej = 1000, 1800, 2600, and 3700; the overall structure of the flow field is found to be qualitatively similar for the Reynolds numbers studied, but the precise trajectory of the mean flow is found to be sensitive to inflow boundary conditions. Reynolds stresses and anisotropic invariants are calculated; the turbulent kinetic energy decreases linearly with increasing distance downstream in the reactor and it decreases at the same relative rate for all Reynolds numbers studied; anisotropic invariants and Reynolds stress maps indicate a turbulent stress state that tends toward isotropy downstream of the inlets. Turbulent stress maps indicate that the Reynolds stress components are stratified in the reactor channel, becoming uniform as a function of z by y/Dh = 4.

Endoscopic 2D particle image velocimetry (PIV) flow field measurements in IC engines

2002 ◽  
Vol 33 (6) ◽  
pp. 794-800 ◽  
Author(s):  
U. Dierksheide ◽  
P. Meyer ◽  
T. Hovestadt ◽  
W. Hentschel
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Particle Image ◽  
Field Measurements ◽  
Image Velocimetry ◽  
Ic Engines

Flow field analysis in a compliant acinus replica model using particle image velocimetry (PIV)

2010 ◽  
Vol 43 (6) ◽  
pp. 1039-1047 ◽  
Author(s):  
Emily J. Berg ◽  
Jessica L. Weisman ◽  
Michael J. Oldham ◽  
Risa J. Robinson
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Particle Image ◽  
Field Analysis ◽  
Image Velocimetry ◽  
Flow Field Analysis

A particle image velocimetry study on the pulsatile flow characteristics in straight tubes with an asymmetric bulge

2000 ◽  
Vol 214 (5) ◽  
pp. 655-671 ◽  
Author(s):  
S C M Yu ◽  
J B Zhao
Keyword(s):  
Particle Image Velocimetry ◽  
Steady Flow ◽  
Pulsatile Flow ◽  
Flow Condition ◽  
Particle Image ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Working Fluid ◽  
Flow Conditions ◽  
Image Velocimetry

Flow characteristics in straight tubes with an asymmetric bulge have been investigated using particle image velocimetry (PIV) over a range of Reynolds numbers from 600 to 1200 and at a Womersley number of 22. A mixture of glycerine and water (approximately 40:60 by volume) was used as the working fluid. The study was carried out because of their relevance in some aspects of physiological flows, such as arterial flow through a sidewall aneurysm. Results for both steady and pulsatile flow conditions were obtained. It was found that at a steady flow condition, a weak recirculating vortex formed inside the bulge. The recirculation became stronger at higher Reynolds numbers but weaker at larger bulge sizes. The centre of the vortex was located close to the distal neck. At pulsatile flow conditions, the vortex appeared and disappeared at different phases of the cycle, and the sequence was only punctuated by strong forward flow behaviour (near the peak flow condition). In particular, strong flow interactions between the parent tube and the bulge were observed during the deceleration phase. Stents and springs were used to dampen the flow movement inside the bulge. It was found that the recirculation vortex could be eliminated completely in steady flow conditions using both devices. However, under pulsatile flow conditions, flow velocities inside the bulge could not be suppressed completely by both devices, but could be reduced by more than 80 per cent.

Measurement of Velocity Profiles of Laminar to Turbulent Water Flows in a Tube Using Particle Image Velocimetry

2004 ◽  
Author(s):  
Meredith R. Martin
Keyword(s):  
Reynolds Number ◽  
Particle Image Velocimetry ◽  
Particle Image ◽  
Glass Tube ◽  
Reynolds Numbers ◽  
Velocity Profiles ◽  
Reynolds Number Flow ◽  
Image Velocimetry ◽  
Dye Visualization ◽  
Number Flow

The transition from laminar to turbulent in-tube flow is studied in this paper. Water flow in a glass tube with an inside diameter of 21.7 mm was investigated by two methods. First, a dye visualization test using a setup similar to the 1883 experiment of Osborne Reynolds was conducted. For the dye visualization, Reynolds numbers ranging from approximately 1000 to 3500 were tested and the transition from laminar to turbulent flow was observed between Reynolds numbers of 2500 and 3500. For the second method, a particle image velocimetry (PIV) system was used to measure the velocity profiles of flow in the same glass tube at Reynolds numbers ranging from approximately 500 to 9000. The resulting velocity profiles were compared to theoretical laminar profiles and empirical turbulent power-law profiles. Good agreement was found between the lower Reynolds number flow and the laminar profile, and between the higher Reynolds number flow and turbulent power-law profile. In between the flow appeared to be in a transition region and deviated some between the two profiles.

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