A plane Couette blog

(latest posts at the top)

Pattern fluctuations in transitional plane Couette flow by Joran Rolland and Paul Manneville looks interesting, about alternatively turbulent and laminar oblique bands. So does From temporal to spatiotemporal dynamics in transitional plane Couette flow by Jimmy Philip and Paul Manneville, Spatiotemporal perspective on the decay of turbulence in wall-bounded flows by Manneville, and On the decay of turbulence in plane Couette flow by Manneville.

Gritsun is working in a 200-d model of barotropic flow.

Andrey Gritsun work on unstable periodic orbits in atmospheric science sounds potentially interesting, but I have not been able to find anything to read about it. They have a 4-year old NSF grant, a number of identical conference abstracts for different conferences in 2007, 2008 and SIAM DS09, but at most one publication: A. Gritsun. "Unstable periodic trajectories of a barotropic model of the atmosphere," Russ. J. Numer. Anal. Math. Modelling, v.23, 2008, p. 345. I am not able to get the article through GaTech library, but from the abstract I do not think he is working with high-dimensional PDEs. There is Kazantsev work from 1998, Gritsun work seems to be a continuation. Kazantsev belongs to the Maryland school of citing, and builds upon the nonsensical formulas of Z—i and Gr——e, but might be worth a read for understanding what the problem is and his methodology of finding periodic orbits. Does not do this stuff any more.— Predrag Cvitanovic 2009-05-01

I saw the Li, Lin paper on arxiv but have not yet studied it in depth. It is interesting. Velocity fields rule!

A Resolution of the Sommerfeld Paradox looks like a paper we should study. — Predrag Cvitanovic 2009-05-01 04:52

Re google code: maybe. I want/plan to move channelflow svn from the GT physics dept, so that it can be seen by the world. Maybe putting it on google code would be good, the whole channelflow website, less likely. The main benefit of channelflow.org is easily-editable pages via dokuwiki. My experience with massive code-hosting sites (freshmeat.net, gnu's savannah.org) is that they're totally inflexible (e.g. probably no dokuwiki), and that not having shell access makes administration a major pain. But I will check it out. Twenty minutes later Hmmm, there is almost no documentation available for code.google.com, nothing that explains what features are support, how much disk space is allowed, etc. Just “click here to host my project”. 2009-05-04.

Axel Brandenburg, Nordita, Stockholm:

• recommends strongly to replace home-maintained website channelflow.org by the google code site, which is free and safer than a locally maintained site (they still copy the entire svn repository to their site, so if google turns evil, one does not lose any of the repository.
  • example: The Pencil Code is maintained on pencil-code.googlecode.com/. Alex has made JohnG a 'project member,' so JohnG can enter and play with the site. Things like svn logs are nicer when displayed on googlecode.com - for example, one can diff on the webiste, without a local svn up.
• In a paper (on his homepage, but I forgot which paper) they showed that one should not plot (I(t),D(t)) but (I(t),D(t+T)), where on varies the delay time T until most of this plot aligns itself along the diagonal. The idea is that enrgy is injected at I(t), but then it takes some time T for it to be dissipated by vorticity. In their astrophysical application this causes a nice data collapse.

grin and bear it. You have now entered the Couette Universe — Predrag Cvitanovic 2009-04-10 09:44

I am unsure of the purpose and scope of this page. All things plane Couette, as the title suggests (that would be like the NYT website having a special “News” subsection), or responses to reviews of n00bs, as the text suggests (in which case the title should reflect that). And you wonder why there are page creation restrictions within my blog … John Gibson 2009-04-09

started here, as no permission to enter Gibson flatlands of Nebraska — Predrag Cvitanovic 2009-04-08 07:53

(the latest posts within a section at the top, blog-style)

moved this to eq8