COST action and particle tracking collaboration benchmarking
Collaboration – Main – Ptvwiki
News COST action “Particles in Turbulence” is the place for collaboration, see http://mp0806.cineca.itWe organize the PTV comparison (open, free and user-friendly, we’ll publish only what you want to be published) in order to make our algorithms validated versus each other and improve our particle tracking abilities worldwide. Write to Alex (alex dot liberzon at gmail dot com) if you want to join with your own version of particle tracking software or with your data test case (e.g. that you find difficult to track or to improve).
The video from the New Scientist
Bubbles are tracked in a wind tunnel using 12 IR cameras. The principle of stereoscopic matching is the one we use for the 3D-PTV (see the wiki at the http://ptvwiki.netcipia.net). this is our main experimental method http://bit.ly/TurbulenceLab
We also need to make some nice visualization. one day.
Tracking bubbles
so MIRA’s work was reviewed by the New Scientist’s journalist, Tom Simonite
I don’t know how to embed their video, so please follow the link by clicking the image below:
http://www.newscientist.com/article/dn17706-soap-bubbles-to-take-the-drag-out-of-future-cars.html
MP0806 COST Workshop of the experimental working group on Particles in Turbulence is over
Thanks to all participants, it’s was very good meeting. We even managed to agree to organize few working groups that will deal with the important subjects. See the ‘road map’
I’ll be responsible for the so-called “PTV challenge”. It’s a great opportunity to start combining best ideas into an open source PTV software package, similar to OpenPIV and the ideas of PIV challenge.
again about flow visualization class of Jean Herzberg
» sciencegeekgirl writes about the flow vis. class of Jean Herzberg
Engineers Make Art: Visualizing Fluid Flow
Thursday, August 20th, 2009 2:20 pm
Contributed by: Stephanie Chasteen
Our
most famous fluids tend to be transparent — air and water, for example.
This makes it hard for us to imagine how fluids are moving as members
of the general public, but also poses an interesting problem for
budding engineers. They need to know how to make fluids do what they
want them to do. So, Jean Herzberg in the Mechanical Engineering
teaches a flow visualization course here at CU. She does it in a fairly novel way, as a hands-on art and science course.
read more on http://expertvoices.nsdl.org/sciencegeekgirl/
interesting parallel between turbulence and economics
Broken Symmetry: A Reynolds Number for Cash-Flow?
A Reynolds Number for Cash-Flow?
George Dyson explains:
In any hydrodynamic system, the non-dimensional Reynolds Number characterizes the ratio between inertial forces (the result of mass and velocity) to viscous forces (the result of the inherent stickiness of the fluid). When the Reynolds number reaches a certain critical value, the system changes from laminar to turbulent flow. There is an equivalent to the Reynolds Number for an economic system: the ratio between the speed (and amplitude) at which currency is flowing through the system to the viscosity of the financial medium. The Reynolds number of our electronically-mediated economy has recently gone way up, with destabilizing results. The latest problem is that automated programs — -the barnacles of the New Economy — -are now trading *within* the frequency spectrum of the turbulent boundary layer. If this happens to a ship, it will slow down, and if it happens to an airplane, it will go into a stall. Where’s the anti-fouling paint?I was unimpressed with the Rushkoff essay to which Dyson is responding. The historical arguments are far too selective in their use of evidence. What about the invention of double-entry bookeeping or the perfection of the patent system in the 19th century? Markets are neither purely constructed nor purely ecological — a key point made by Vernon Smith in his latest treatise.
i was trully convinced that we knew that pressure shows separation
ן ‘Tecplot: Relieving the Pressure in Calculating Flow Separation by Desktop Engineering
In any simulation, obtaining accurate results is only half the battle. Whether the domain is material stress or fluid flow, any data is only as good as the engineer’s ability to interpret and apply it.
One of the more important yet difficult calculations to understand is the precise behavior of the breakaway of fluid from walls. However, after five years of research, a team of scientists from MIT, San Diego State University, and United Technologies has developed a breakthrough methodology that allows engineers to precisely determine the location and angle of flow separation in both 2D and 3D as well as steady and unsteady flow conditions.
“Visualization of steady flow vs. unsteady flow can be compared to looking at a static image vs. a movie,” notes Mike Peery, president of TecPlot, Inc. in Bellevue, WA. “The work they did isolates the steady parameters from the craziness of unsteady flow.”
The ramifications of this development are far reaching, from minimizing drag in automobiles to improving cooling of turbine blades (see “Turbine Benefit”), as industries strive for greater energy efficiency and fuel economy.
so why the flies don’t spin?
we just think about ‘explosives detection’ and what do we find?
Engineers have long been stymied in their attempts to fabricate micro aerial robots that can match the amazing flight capabilities of nature’s most advanced flying insects ¾flies. Such robot flies — if they could be made efficient enough for long missions — could be used for a variety of tasks, from spying, to mine detection to search and rescue missions in collapsed buildings.
…
The new work shows which wing motion generates high lift most effectively — the insect wing that spins around similar to a helicopter blade. Nevertheless, we still have much to learn from flies, says Dickinson. These tiny animals have evolved into some of nature’s best fliers and whereas the micro batteries of humans can keep their fly-sized robots aloft for mere seconds or minutes, flies can fly effortlessly for hours. ‘With such an effective form of energy storage and motors, flies are much less dependent on energy efficiency than our best robot flies,” says Dickinson> “We can still learn from nature how to improve our flying robot designs, but not without a better understanding of why flies fly so well.”
Source:
Micro flying robots can fly more effectively than flies
so why the flies don’t spin?
we just think about ‘explosives detection’ and what do we find?
Engineers have long been stymied in their attempts to fabricate micro aerial robots that can match the amazing flight capabilities of nature’s most advanced flying insects ¾flies. Such robot flies — if they could be made efficient enough for long missions — could be used for a variety of tasks, from spying, to mine detection to search and rescue missions in collapsed buildings.
…
The new work shows which wing motion generates high lift most effectively — the insect wing that spins around similar to a helicopter blade. Nevertheless, we still have much to learn from flies, says Dickinson. These tiny animals have evolved into some of nature’s best fliers and whereas the micro batteries of humans can keep their fly-sized robots aloft for mere seconds or minutes, flies can fly effortlessly for hours. ‘With such an effective form of energy storage and motors, flies are much less dependent on energy efficiency than our best robot flies,” says Dickinson> “We can still learn from nature how to improve our flying robot designs, but not without a better understanding of why flies fly so well.”
Source:
Micro flying robots can fly more effectively than flies
Lagrangian vs Eulerian part 3
Fluid Mechanics (Eulerian and Lagrangian Description part 3)
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