Simultaneous three-dimensional temperature and velocity field measurements using astigmatic imaging of non-encapsulated thermo-liquid crystal (TLC) particles

Lab on a Chip ◽  
2015 ◽  
Vol 15 (3) ◽  
pp. 660-663 ◽  
Author(s):  
Rodrigo Segura ◽  
Massimiliano Rossi ◽  
Christian Cierpka ◽  
Christian J. Kähler
Keyword(s):  
Liquid Crystal ◽  
Velocity Field ◽  
Three Dimensional ◽  
Field Measurements ◽  
Velocity Measurements ◽  
Time Resolved

TLC thermography and APTV for simultaneous time-resolved 3D temperature and velocity measurements in microflows.

High Speed Micro Holographic PIV Measurements of Microorganisms

2008 ◽  
Author(s):  
M. Zarzecki ◽  
F. J. Diez
Keyword(s):  
Velocity Field ◽  
High Speed ◽  
Fourier Transforms ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Imaging Method ◽  
Time Resolved ◽  
Feeding Methods ◽  
Holographic Particle Image Velocimetry ◽  
Three Components

Holographic particle image velocimetry (PIV) is a novel application of holography that allows for tracking of small particle sized objects in a small volume. Whereas regular PIV allows for the two in-plane components of the velocity field to be measured, and stereoscopic PIV allows for the three-components of the velocity field to be measured in a thin plane, holographic PIV allows for the three-components of the velocity to be measured for each individual particle present in the measuring volume, thus allowing to fully resolve fluid flows that are inherently 3D in nature. There are many examples of three dimensional flows in nature including turbulence flows, but another very interesting application very well suited for this technique involves tracking living microorganisms in order to study their motion and their means of propulsion. As part of this research a micro organism was tracked in three dimensions using a high speed microscopic holographic imaging method. The ability to track organisms in 3D allows better understanding and characterizing of their behavior including their propulsion methods, their feeding methods and their interaction with each other. The time resolved holograms were reconstructed in Matlab using Fast Fourier Transforms. A laser pointer was used as a source of coherent light, and a high speed PIV camera (Photron APX Ultima) was used to capture the images. A beam expander was used to increase the diameter of the laser beam allowing for a larger tracking area. Results with this system will show the trajectories in 3D of microorganisms as well as the three components of the velocity field showing the interaction of the organisms with their environment.

Noninvasive Measurement of Time-Varying Three-Dimensional Relative Pressure Fields Within the Human Heart

2002 ◽  
Vol 124 (3) ◽  
pp. 288-293 ◽  
Author(s):  
T. Ebbers ◽  
L. Wigstro¨m ◽  
A. F. Bolger ◽  
B. Wranne ◽  
M. Karlsson
Keyword(s):  
Velocity Field ◽  
Human Heart ◽  
Three Dimensional ◽  
Computational Fluid Mechanics ◽  
Relative Pressure ◽  
Time Resolved ◽  
Pressure Poisson Equation ◽  
Pressure Fields ◽  
Flow Phenomena ◽  
Human Left Ventricle

Understanding cardiac blood flow patterns is important in the assessment of cardiovascular function. Three-dimensional flow and relative pressure fields within the human left ventricle are demonstrated by combining velocity measurements with computational fluid mechanics methods. The velocity field throughout the left atrium and ventricle of a normal human heart is measured using time-resolved three-dimensional phase-contrast MRI. Subsequently, the time-resolved three-dimensional relative pressure is calculated from this velocity field using the pressure Poisson equation. Noninvasive simultaneous assessment of cardiac pressure and flow phenomena is an important new tool for studying cardiac fluid dynamics.

The Velocity Field of an Annular Jet With “Cross-Member”

2003 ◽  
Author(s):  
John F. Foss ◽  
Richard J. Prevost ◽  
Kyle M. Bade ◽  
Aure´lien Levasseur
Keyword(s):  
Velocity Field ◽  
Field Data ◽  
Three Dimensional ◽  
Field Measurements ◽  
Delivery Tube ◽  
Piv Measurements ◽  
Annular Jet ◽  
Flat Disk ◽  
Cross Member ◽  
Central Plug

An annular jet has been created by supporting a streamlined plug (dia = D1) in a delivery tube (dia = D2) with a narrow cross-member. PIV measurements have been carried out at x/D2 = 8 for four D1/D2 ratios. These observations, and the motivating criteria for this study, were used to select D1/D2 = 0.746 for detailed, near exit, velocity field measurements. Significant three-dimensional effects of the cross-member have been observed. Velocity field data, from a “sting supported, flat disk” (axisymmetric geometry) central plug provide comparative measurements. These comparisons are considered in detail.

Operational Model and its Validation with Drift Tests in Water Areas Around the Baltic Sea

1994 ◽  
Vol 29 (2-3) ◽  
pp. 293-308
Author(s):  
J. Koponen ◽  
M. Virtanen ◽  
H. Vepsä ◽  
E. Alasaarela
Keyword(s):  
Three Dimensional ◽  
Fast Response ◽  
Velocity Measurements ◽  
Short Term ◽  
Large Lakes ◽  
Operational Model ◽  
Water Currents ◽  
Emergency Situations ◽  
Sensitivity Tests ◽  
The Baltic

Abstract Three-dimensional (3-D) mathematical models of water currents, transport, mixing, reaction kinetic, and interactions with bottom and air have been used in Finland regularly since 1982 and applied to about 40 cases in large lakes, inland seas and their coastal waters. In each case, model validity has been carefully tested with available flow velocity measurements, tracer studies and water quality observations. For operational use, i.e., for spill combatting and sea rescue, the models need fast response, proven validity and illustrative visualization. In 1987-90, validated models were implemented for operational use at five sea areas along the Finnish coast. Further validation was obtained in model applications from nine documented or arranged cases and from seven emergency situations. Sensitivity tests supplement short-term validation. In the Bothnian Sea, it was nescessary to start the calculation of water currents three days prior to the start of the experiment to reduce initial inaccuracies and to make the coastal transport estimates meaningful.

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