[Nek5000-users] turbulent 3d box

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

Hi Barak,

Thanks for the note about the ABC flow -- that's very useful.

What is your target viscosity?
If you want it to be 0.1, then you would set param 2 in the .rea file to be 0.1.
Setting param 2 = -0.1 would imply that Re=0.1 or equivalently nu=10.
Does this resolve the issue for you?

Once it's working we could add it as a documented example in the example
suite.

Thanks!

Paul
________________________________________
From: nek5000-users-bounces at lists.mcs.anl.gov [nek5000-users-bounces at lists.mcs.anl.gov] on behalf of nek5000-users at lists.mcs.anl.gov [nek5000-users at lists.mcs.anl.gov]
Sent: Saturday, December 21, 2013 5:24 PM
To: nek5000-users at lists.mcs.anl.gov
Subject: Re: [Nek5000-users] turbulent 3d box

Hi Paul,
Regarding the 3dbox:
The forcing which I propose is known as the ABC flow
(Arnold-Beltrami-Childress) and has steady solutions (in the form of ABC
flow) with Re=1/nu (nu the viscosity) Re=<12 (in periodic box).
The forcing should be in the form:
f=Re*ABC in order to balance the dissipation term.
This settings can serve as a benchmark for pure hydro/mhd problems.

I tried to fix the example which you have sent me, but I don't succeed
retreiving the expected values.
I attach the relevant files( tarball file).
Best regards,
Barak



On 12/18/2013 03:29 AM, nek5000-users at lists.mcs.anl.gov wrote:
>
> Hi Barak,
>
> I added a 3d periodic box under "3dbox" in the examples
> directory.
>
> Paul
>
>
> Dear nek's,
> I would like to run the following problem:
> a 3D periodic box, small viscosity and the following forcing:
>
> fx=cos(y)+sin(z)
> fy=cos(z)+sin(x)
> fz=cos(x)+sin(y)
>
> Do you have a similar example?
>
> Many thanks,
> Barak
>
>
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