[Nek5000-users] Vorticity as initial condition

[nek5000-users at lists.mcs.anl.gov]

Hello Ishmael
The code uses a kernel regularization technique to avoid the singularity in
the integrand. This has a parameter delta; try to change it and see what
happens.

If you use the P(n)-P(n-2) scheme, then you could integrate on the pressure
mesh. This should avoid the singularity problem and you dont need the
regularization. This may be a better approach.

Best
praveen


On Wed, Feb 12, 2014 at 11:04 PM, <nek5000-users at lists.mcs.anl.gov> wrote:

> (Wed, Feb 12, 2014 at 06:23:13PM +0100) nek5000-users at lists.mcs.anl.gov :
> > (Wed, Feb 12, 2014 at 06:39:58PM +0530) nek5000-users at lists.mcs.anl.gov:
> > > In a 2-d case involving a vortex dipole, I have used Biot-Savart law to
> > > calculate the velocity. This is very inefficient of course, and I could
> > > only run it in serial. If you want to see, it is here
> > >
> > >
> https://code.google.com/p/cfdlab/source/browse/trunk/nek5000/vortex_dipole/
> > >
> > > See initcond.usr and the function usrchk.
> >
> > Hi,
> >
> > I had a try with your code, and it looks very strange with your example
> > case (A lot of noise). However it looks perfect with the one that I want,
> > which is only radial vorticity, so thank you very much for your help!
>
> Sorry, I spoke too fast: I was looking twice at the same image...
> I have strange behavior of the initcond routine: you can see here the
> initial vorticity and the vorticity -> velocity -> vorticity.
> http://www.normalesup.org/~bouya/temp/vorticity.png
>
> They don't look the same at all, even if one can more or less "guess" the
> calculated value in the middle. Did you have the same kind of issues?
> Did I miss something? (I tried to follow the steps in the README file)
>
> Thanks!
>
> Best regards,
> --
> Ismael
>
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