gtspring2009
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gtspring2009 [2009/07/08 10:47] dborrero |
gtspring2009 [2011/08/10 08:11] (current) predrag John, please confirm that you get notices about channelflow updates |
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| - | |[[gtspring2009:schedule]] | [[gtspring2009:participants]] | [[gtspring2009:BlogOfBlogs|blogs]] | [[gtspring2009:research projects]] | [[gtspring2009:description|study group description]] | [[gtspring2009:howto|howto]] | | + | | [[gtspring2009:BlogOfBlogs|blogs]] | [[:chaosbook| ChaosBook blog]] | [[gtspring2009:research projects]] | [[gtspring2009:howto|howto]] | [[:|Channelflow]] | [[http://ChaosBook.org/tutorials|tutorials]] | [[gtspring2009:description|study group]] | [[gtspring2009:schedule]] | [[gtspring2009:participants]] | |
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| - | <span style="color:red;font-size:80%;text-align:right;">please check this page a few times a week, there will be no emails</span> | + | <span style="color:red;font-size:80%;text-align:right;">please check this page a few times a week, there will be no emails: , click on [Recent changes], select changed page, then [Old revision], compare versions</span> |
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| - | {{gtspring2009:dbthumb.png?24 }}Also, there is new paper by Nigel Goldenfeld's group that predicts super-exponential scaling of the lifetimes of transitional states with increasing Reynolds number. As far as I'm aware, it is the first theoretical prediction for a scaling law. You can find it [[http://aps.arxiv.org/PS_cache/arxiv/pdf/0906/0906.3572v2.pdf| here]] --- //[[dborrero@gatech.edu|D. Borrero]] 2009-07-08 13:35// | + | {{gtspring2009:pc.jpg }} request to John: Can you pencil in the group orbit of the Nagata upper branch on the same kind of plot as [[http://chaosbook.org/tutorials/Images/a1.14_g2.png|full states space portrait]]? The last time you plotted this {{:chaosbook:pipes:tangenta.png?200 |}} was 2006-01-02 (the figure inserted here), and that was before we knew how to project onto solutions in the states space, so I suspect the wiggles in the far end of the torus are due to the projection on Fourier modes. The reason I need the group orbit traced out is to illustrate that several slices might be needed to reduce the symmetry. A slice is a (d-2) hyperplane in this plot, and it intersects the group orbit torus in at least two points - the closest and the furthest to the template. However, as turbulent solutions involve of order of at least 100 Fourier/Chebyshev modes of comparable magnitude, the torus embedded into the state space should be quite wiggly, and have a number of local extrema (intersections with the slice hyperplane). Ashly has done it for a pipe lower-branch equilibrium, but that one is too nice a torus to illustrate the general problem... Gratful if you could do it - involves only translating |
| + | the UB in spanwise/streamwise increments and plotting the issuing mesh. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2011/08/05 12:35// | ||
| - | {{gtspring2009:dbthumb.png?24 }}Hey all! Is anybody familiar with compressing a large number of small files. I have over a terrabyte of data that is currently stored as small matlab .mat files (~750 KB each) in a hierarchy of directories (the top level directories contain several GB of data which are then divided among a few hundred subdirectories that vary in size from a couple of MB to a few hundred MB). I'm running low on storage space and am considering compressing the data, but I'm not 100% what the best way to do that is for such a large structure. I guess I could write a batch script to go through and compress each file individually, but this does not sound optimal. Does anybody have any better ideas? Also, does anybody have any suggestions as to which compression format will work best? --- //[[dborrero@gatech.edu|D. Borrero]] 2009-07-08 13:29// | + | {{gtspring2009:pc.jpg }} Woods Hole GFD snippets: Listening to [[http://www.mcnd.manchester.ac.uk/mullin.html|Tom Mullin]]: the flow in expanding pipes experiments are very interesting. Bifurcation analysis is worth dog turds - messy stuff happens much earlier. This problem is seriously begging for symmetry reduction. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2011/08/10 08:06// |
| - | I posted a list of [[gtspring2009:spieker_blog#table_of_solution_properties|field properties]] of the W03 solutions in my blog. As you might notice, dissipation and L2 norm are the only properties I am listing so far. Those are the two I am checking candidates for new solutions against. I think the table should not only be added to, but also put in a more resourceful location. I am up for suggestions. --- //[[dustin.spieker@gatech.edu|Dustin Spieker]] 2009-07-06 15:00// | + | {{gtspring2009:pc.jpg }} Woods Hole GFD snippets: Listening to [[http://www.mech.kth.se/~henning/|Dan Hennignson]]: watching their [[http://www.youtube.com/watch?v=4KeaAhVoPIw|movies of the boundary layer]] is very fascinating - if you find them on their homepage, please put a link here. Used 5000 processors for 6 months; amounts to 40 cm of Boing 747. Wu & Moin recent work claims that the [[http://www.youtube.com/watch?v=GW2LRo2ZigQ|initial forest of hairpin vortices survives]]. Not correct. They do not look at as high Reynolds numbers. They do not get the averages right. Henningson results are much better, and the transition region does not persist. For plane Couette, 800 1/2 heights domain, showed a movie that shows that initial noisy conditions go into stripes. That justifies using smaller cells. |
| - | {{gtspring2009:gibson.png?24 }} Done, see [[gtspring2009:howto:pace#submit_a_job_to_the_queue|the PACE howto]]. Thanks for the tip | + | Study this: They use Lagrange multipliers method to get to the adjoint Navier-Stokes evolution (this might be the way to deal with Domenico's noise evolution for hyperbolic fixed points, as well). Dan finds it remarkable that it works in optimized perturbation settings. This was discussed in detail in the talk "Questioning the question: The role of nonlinear optimal perturbations in the transition to turbulence of plane Couette flow" by [[http://www.damtp.cam.ac.uk/people/c.p.caulfield/|Colm-cille Caulfield]]. ([[http://en.wikipedia.org/wiki/Columba|Colm-cille]] is an Irish name). Concerning finite amplitude perturbations for plane Couette transition from laminar to optimal (Monokrousos et al (2011)): For dissipation norm, with the same energy disturbance, //localized// disturbances are optimal (but not too localized - would be interesting to understand the scale). Numerical observations support this - the point where transition happens are localized. He showed a few movies where localized -> vortex pair -> streak, grow due lift-up effect -> and pretty turbulent looking edge state. It is the Orr mechanism of generating a 2D packet (the strongest transient growth mechanism in 2D, a version of Kelvin circulation theorem), but it is essential that disturbance is 3D, or Orr mechanism would make the perturbation die away. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2011/08/04 07:12// |
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| + | {{gtspring2009:pc.jpg }} If you want to fall asleep, [[http://www.jove.com/details.php?id=2152|biology video journal]] is the way to go. Still, it is intriguing way to publish, might be useful for complicated state-space narratives. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2011-02-01 20:23// | ||
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| + | {{gtspring2009:pc.jpg }} [[http://www.openfoam.com/|www.openfoam.com]] open source CFD seems interesting --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2010-11-02 17:51// | ||
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| + | {{gtspring2009:pc.jpg }} [[http://www.fenicsproject.org/wiki/FEniCS_Project|FEniCS project]] software for automated solution of differential equations looks interesting. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2010-10-25 19:23// | ||
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| + | * Jeff, [[http://music-illuminati.com/|the flip side of]] | ||
| + | * [[http://www.youtube.com/watch?v=TdicSaJBwYQ|Ally Moe Designs fashion show beats Wet & Wild hands down.]] The distance form Jawja to Santa Barbara equals the distance form here to Dog Star. | ||
| + | * The [[http://www.flickr.com/photos/birdtracks/sets/72157622595634417/|Hof lab]], featuring photos of the plane Couette experiment. So far in air only, the 3 tons of water will be added Jan 2010. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2009-12-17 23:10// | ||
| + | * The unofficial [[http://www.flickr.com/photos/birdtracks/sets/72157622720110890/|Prandtlitos Juniors]] homepage. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2009-12-16 00:07// | ||
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| + | {{gtspring2009:pc.jpg }} Plumbers have been publicity grabbing recently: you might want to read Guenter Ahlers: //[[http://physics.aps.org/articles/v2/74|Turbulent convection]]// and NYT 09/28/09 //[[http://www.nytimes.com/2009/09/29/science/29chaos.html|Finding Order in the Apparent Chaos of Currents]]// for your own edification. I have hear two very good talks by Guenter Ahlers recently, if I find them somewhere I'll link them here. Especially cute is their Santa Barbara work on turbulence within a cyllinder; the turbulent flow drifts, dragged by Earth's Corriolis force. | ||
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| + | {{gtspring2009:pc.jpg }} I put [[http://chaosbook.org/library/index.html#etc12_proceed|Marburg turbulence conference ETC12 proccedings]] into ChaosBook.org library. Lots of our kind of shmurbulence here. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2009-09-09 06:41// | ||
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| + | {{gtspring2009:pc.jpg }} to Dustin: Talked to [[gtspring2009:gibson:eq8|Itano]] about [[:gtspring2009:research_projects#open_projects|Itano etal visualization]]. Says we can quickly learn how to do it ourselves. Maybe give it a try? --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2009-09-08 10:00// | ||
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| + | :?: I followed the procedure on the [[gtspring2009:howto|howto]] for finding new equilibrium solutions and like some sort of Christmas Miracle, I found an equilibrium on my first try. --- //[[dustin.spieker@gatech.edu|Dustin Spieker]] 2009-08-19 08:27// | ||
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| + | {{gtspring2009:pc.jpg }} PC 2009-07-30: [[:gtspring2009:predrag:blog#on_spatially_localized_solutions|On spatially localized solutions:]] go hetero, or go unstable periodic? | ||
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| + | {{gtspring2009:pc.jpg }} a more detailed report from [[gtspring2009:predrag:blog#trieste_2009_turbulence_conference|Trieste Turbulence 2009]]. Read in particular the new text in Halcrow svn blog. If someone would like to do something new of interest to the turbulence community, Yakhot suggest computing several scaling exponents from our exact solutions. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2009-07-29 03:17// | ||
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| + | {{gtspring2009:gibson.png?24 }} Dustin, John Hyatt, would either of you be interested in seeing which of our EQB solutions could be continued to [2pi,2, pi] or [4pi, 2, 2pi]? It would be nice if most of them carried over and we could abandon our strange [2pi/1.14, 2, 2pi/2.5] box. Also, I would like to replace the binary .ff files in the database with H5 datafiles. **UPDATE** For the record I have already continued EQ1, EQ2, EQ4, EQ7, EQ9, and EQ10 to Lx,Lz = 2pi,pi. //John Gibson 2009-07-29 // | ||
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| + | {{gtspring2009:gibson.png?24 }} Moved channelflow subversion server from zero.physics.gatech.edu to [[http://svn.channelflow.org/channelflow]]. Allows easier and more universal access (no need to tunnel through ssh.physics.gatech.edu, online browsing via [[http://websvn.tigris.org|WebSVN]]). For study group participants, I recommend downloading channelflow via SVN rather than using the tarballs. It's much | ||
| + | better for distributing quick fixes. See [[docs:install|Installation]]. //John Gibson 2009-07-20 22:30 EST// | ||
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| + | {{gtspring2009:gibson.png?24 }} Upgraded dokuwiki to the latest release. Please let me know if you notice any glitches with the channelflow site or your blogs. // John Gibson 2009-07-20 14:07 EST// | ||
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| + | {{gtspring2009:dbthumb.png?24 }} There is a new paper by Nigel Goldenfeld's group that predicts super-exponential scaling of the lifetimes of transitional states with increasing Reynolds number. As far as I'm aware, it is the first theoretical prediction for a scaling law. You can find it [[http://arxiv.org/abs/0906.3572|arXiv.org/abs/0906.3572]] --- //[[dborrero@gatech.edu|D. Borrero]] 2009-07-08 13:35// | ||
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| + | {{gtspring2009:gibson.png?24 }} for Daniel: [[gtspring2009:howto:compress|how to compress data files]]. | ||
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| + | :-) Posted a list of [[gtspring2009:spieker_blog#table_of_solution_properties|field properties]] of the W03 solutions in my blog. I think the table should not only be added to, but also put in a more resourceful location. I am up for suggestions. --- //[[dustin.spieker@gatech.edu|Dustin Spieker]] 2009-07-06 15:00// | ||
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| + | {{gtspring2009:gibson.png?24 }} See [[gtspring2009:howto:pace#submit_a_job_to_the_queue|the PACE howto]]. Thanks for the tip | ||
| on the continuesoln bug. I'm back from Minnesota but will not be on skype until I get a new sound card. Will try to do that this afternoon. //John Gibson 2009-06-29 10:09 EST// | on the continuesoln bug. I'm back from Minnesota but will not be on skype until I get a new sound card. Will try to do that this afternoon. //John Gibson 2009-06-29 10:09 EST// | ||
| - | John G: I was wondering if you could put up an example script that you would qsub to the cluster. I got channelflow to compile on in my home directory on pacemaker, and all that is left for me to do is exploit the raw computing power. There is also a small error (that I've found) in the continuesoln code that needs to be adjusted. continuesoln, for equilibria, generates T.asc files. If you want to read in solutions that already exist, however, continuesoln wants to read in Tbest.asc. In the next distribution, that would be worth correcting. ---//[[dustin.spieker@gatech.edu|Dustin Spieker]] 2009-06-17 12:00// | + | :?: to John: Can you put up an example script that you would qsub to the PACE cluster? ---//[[dustin.spieker@gatech.edu|Dustin Spieker]] 2009-06-17 12:00// |
| {{gtspring2009:gibson.png?24 }} I'll be off in Minnesota for two weeks, June 13th-27th ([[http://www.cns.gatech.edu/~gibson/travel.txt|schedule, phone numbers]]). Just wanted to alert you all. Internets access will be spotty but I will check in when I can. | {{gtspring2009:gibson.png?24 }} I'll be off in Minnesota for two weeks, June 13th-27th ([[http://www.cns.gatech.edu/~gibson/travel.txt|schedule, phone numbers]]). Just wanted to alert you all. Internets access will be spotty but I will check in when I can. | ||
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| Continuation of solutions via repeated changegrid and findorbit should work fine. When you get the hang of that, try out the continuation utility. Its advantages are speed (it can take larger steps in parameter space), automation, and ability to continue around a corner from a lower to and upper branch (or vice versa). /// John Gibson 2009-06-05 12:22 EST// | Continuation of solutions via repeated changegrid and findorbit should work fine. When you get the hang of that, try out the continuation utility. Its advantages are speed (it can take larger steps in parameter space), automation, and ability to continue around a corner from a lower to and upper branch (or vice versa). /// John Gibson 2009-06-05 12:22 EST// | ||
| - | Hey John, could you post a data file for the 47.18 periodic orbit for me. Thanks. Also, I have generated about 90 flow fields that I think are continuations of the Upper Branch Solution. I say "I think" because instead of using the continue solution utility, I used changegrid then I used findorbit to find a solution. Do these calculations have merit or do I need to use continuesoln? --- //[[dustin.spieker@gatech.edu|Dustin Spieker]] 2009-06-02 09:24// | + | :?: to John: Could you post a data file for the 47.18 periodic orbit for me? Also, I have generated about 90 flow fields that I think are continuations of the Upper Branch Solution. I say "I think" because instead of using the continue solution utility, I used changegrid then I used findorbit to find a solution. Do these calculations have merit or do I need to use continuesoln? --- //[[dustin.spieker@gatech.edu|Dustin Spieker]] 2009-06-02 09:24// |
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| + | ====== Spring 2009 ====== | ||
| {{gtspring2009:gibson.png?24 }} Hi, Dustin. Sorry for the wait. I was at a conference, then had a long weekend, and now computer trouble (am reinstalling SUSE-11.1 on my home desktop as we speak). It sounds to me like findorbit is looking for equilibrium solutions rather than periodic orbits. The current version requires you to specify -orb or -eqb, which adds/removes the integration time T to/from the search space. If the version you're running doesn't require -orb or -eqb, it defaults to one or the other. Run findorbit -h to see which. I bet it defaults to eqb, in which case T=47 is a long time and close enough to the period of the unstable oscillation around EQ2 that it might be stuck in a local minimum. //John Gibson 2009-05-27 11:33 EST// | {{gtspring2009:gibson.png?24 }} Hi, Dustin. Sorry for the wait. I was at a conference, then had a long weekend, and now computer trouble (am reinstalling SUSE-11.1 on my home desktop as we speak). It sounds to me like findorbit is looking for equilibrium solutions rather than periodic orbits. The current version requires you to specify -orb or -eqb, which adds/removes the integration time T to/from the search space. If the version you're running doesn't require -orb or -eqb, it defaults to one or the other. Run findorbit -h to see which. I bet it defaults to eqb, in which case T=47 is a long time and close enough to the period of the unstable oscillation around EQ2 that it might be stuck in a local minimum. //John Gibson 2009-05-27 11:33 EST// | ||
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| {{gtspring2009:pc.jpg}} Re [[gtspring2009:howto:format|howto:format]] page: I would like to get the [[http://apps3.aps.org/gsnp/galleryinfo.cfm|APS Nonlinear Gallery]] to require flash and flash only (at least half of the formats used this year needed downloading things like [[http://www.videolan.org/vlc/|VLC media player]] in order to be seen). | {{gtspring2009:pc.jpg}} Re [[gtspring2009:howto:format|howto:format]] page: I would like to get the [[http://apps3.aps.org/gsnp/galleryinfo.cfm|APS Nonlinear Gallery]] to require flash and flash only (at least half of the formats used this year needed downloading things like [[http://www.videolan.org/vlc/|VLC media player]] in order to be seen). | ||
| - | {{gtspring2009:gibson.png?24}} Study group participants: Don't be shy about calling me. johnfgibson on skype, 617-441-3609 on phone. I have a brand-new, clear-as-a-bell headset for skype. //John Gibson 2009-03-25 10:53 EST// | + | {{gtspring2009:gibson.png?24}} Study group participants: Don't be shy about calling me. johnfgibson on skype, 617-441-3609 begin_of_the_skype_highlighting 617-441-3609 end_of_the_skype_highlighting begin_of_the_skype_highlighting 617-441-3609 end_of_the_skype_highlighting begin_of_the_skype_highlighting 617-441-3609 end_of_the_skype_highlighting begin_of_the_skype_highlighting 617-441-3609 end_of_the_skype_highlighting begin_of_the_skype_highlighting 617-441-3609 end_of_the_skype_highlighting begin_of_the_skype_highlighting 617-441-3609 end_of_the_skype_highlighting begin_of_the_skype_highlighting 617-441-3609 end_of_the_skype_highlighting begin_of_the_skype_highlighting 617-441-3609 end_of_the_skype_highlighting on phone. I have a brand-new, clear-as-a-bell headset for skype. //John Gibson 2009-03-25 10:53 EST// |
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| {{gtspring2009:pc.jpg}} Same here - if I'm on skype, call - I can help with dynamical systems kinds of questions. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2009-03-25 07:58// | {{gtspring2009:pc.jpg}} Same here - if I'm on skype, call - I can help with dynamical systems kinds of questions. --- //[[predrag.cvitanovic@physics.gatech.edu|Predrag Cvitanovic]] 2009-03-25 07:58// | ||
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| {{gtspring2009:gibson.png?24 }} [[:gtspring2009:research_projects:gibson:blog#state_space_portraits|Gibson blog - State-space portraits]]: added a set of HKW periodic orbit projections | {{gtspring2009:gibson.png?24 }} [[:gtspring2009:research_projects:gibson:blog#state_space_portraits|Gibson blog - State-space portraits]]: added a set of HKW periodic orbit projections | ||
| --- //[[gibson@cns.physics.gatech.edu|John F. Gibson]] 2009-01-07// | --- //[[gibson@cns.physics.gatech.edu|John F. Gibson]] 2009-01-07// | ||
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gtspring2009.1247075254.txt.gz · Last modified: 2009/07/08 10:47 by dborrero
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