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--- gtspring2009:gibson:eq8 [2009/06/10 14:02]
predrag pruned the page for good tact and tone. You can make it publicly readable, or not, if you prefer. Please invite I&G to join the wiki, after you have done the final read-through on this page
+++ gtspring2009:gibson:eq8 [2010/02/02 07:55] (current)
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 <html><span style="color:red;font-size:80%;text-align:right;">[the latest posts at the top of this page]</span></html>
-{{gtspring2009:gibson.png?24}}  Their visualization technique is very beautiful, though I think it must involve some arbitrary choices on where to start the vortex lines. I would like to try the same for the other solutions. It would be nice to get their scripts. I agree with you on "tertiary" etc. I think "asymptoting to laminar" is probably wrong -that was one of the main points of the Wang, Gibson, Waleffe PRL, at least for the Nagata lower branch. //John Gibson 2009-06-09 //
+posts after 2009-07-01 [[:gtspring2009:spieker_blog:itano|are here]]
+----
+{{gtspring2009:gibson.png?24}} //2009-07-01 12:09 EST// Got an email from Soto Generalis <s.c.generalis@aston.ac.uk>:
+----
+Dear Prof Gibson,
+We are both so sorry for not contacting you much earlier than we are doing now. It is a very busy period here in the UK. This is not really a good excuse for not replying earlier, but the administrative duties that are coupled with our appointments are temporally demanding although albeit mundane.
+As we mentioned before it was the suggestion of one of the referees to make contact with your group and your work and compare our solutions with the solutions of your team. We understand from your email below that the manuscript that you submitted to the JFM is now in its final stages prior to its publication. We are both grateful that you have provided the link for the revised version of your manuscript and we both wish you success in publishing your manuscript.
+We also agree with you that there are other solutions as you describe below. It would be interesting to compare solutions and as a starting point would you agree that the value for Re_{min} \approx 174? Would you be able to confirm to us that the lowest value of the Reynolds number of EQ8 is the above mentioned one when the stream- and span- wise wavenumbers are fixed at the values of 1 and 2 respectively? We could provide you with a slightly more accurate value that we have obtained with our methods, but the value 174 was the one that was reported in our PRL paper.
+We will be in contact soon,
+Tomoaki Itano and Sotos Generalis.
+----
+My response:
+Dear Profs. Itano and Generalis:
+I am glad to hear from you. I certainly understand how busy academic life is! Our EQ7/EQ8 solution has Re_{min} \approx 174 with streamwise,spanwise wavenumbers fixed at alpha. gamma = 1,2, the same as your HVS solution. The lowest value of Re we found was 174.07, but we did not try to determine that precisely. The dissipation vs Reynolds number plot appears to be the same as well. I've attached a figure and some Re vs D data. We have normalized dissipation D == wall shear I so that the laminar solution has D = I = 1. We have also compared the symmetries of our solution to yours, and they are the same (up to phase shifts). So I'm pretty sure the solutions are the same.
+I'm not sure that we need further comparisons, but if you would like to examine our solutions,
+the data is available at www.channelflow.org/database in tar-gzip files of ascii data for velocity at Fourier-Chebyshev gridpoints. The data format is explained in detail towards the bottom of the page. The data posted is for alpha=1.14 gamma=2.5; if you would like alpha=1, gamma=2 I can send that to you directly.
+We like your visualization scheme very much. Would you consider sharing your visualization scripts with us, so that we could look at some of our other solutions this way?
+Our paper has been accepted by JFM and should appear in print soon.
+best regards,
+John
+----
+{{gtspring2009:gibson.png?24}}  Their visualization technique is very beautiful. I think you're right (Predrag) about choosing some initial points arbitrarily and then integrating lines tangent to the vorticity field. I would like to try the same for the other solutions. It would be nice to get their scripts. I agree with you on "tertiary" etc. I think "asymptoting to laminar" is probably wrong -that was one of the main points of the Wang, Gibson, Waleffe PRL, at least for the Nagata lower branch. "Mean shear rate" is vague, implies (to me) the temporal mean rather than the time-varying spatial mean. Perhaps just "shear rate".
+//John Gibson 2009-06-09 //
 {{gtspring2009:pc.jpg}} Notes on [[http://chaosbook.org/library/ItGe09.pdf|Itano and Generalis paper]]. <html>

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