[Nek5000-users] New Recycling BC based on interpolation

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

Hi Michael,

In this test case, we just only one inlet with 'v  ' for Recycling BCs and 'W  ' for no-slip wall and there was no need for further discriminator like coordinates, faces, etc. as Paul has just suggested. 


In case you need to use RBC for two inlets both with RBCs but different ubar/s1, you can have in addition to total number of points npts also an array of number of points for each inlet like napts = [npts1,npts2] which you can set in set_inflow/get_shift.  

Then in rescale_inflow instead of a single loop over total npts you need to have subloops over the conent of napts each of them rescaling to the different value of ubar according to the inlet.

Best,
Aleks




----- Original Message -----
From: nek5000-users at lists.mcs.anl.gov
To: nek5000-users at lists.mcs.anl.gov
Sent: Friday, July 16, 2010 4:47:11 PM GMT -06:00 US/Canada Central
Subject: Re: [Nek5000-users] New Recycling BC based on interpolation


Hi Michael,

Use whatever discrimination you like --- I would not suggest
modifying the character bcs, however, save that you can enter
values in bc(k,f,e,1) for k > 1, for any cbc(f,e,1) = 'v  '

The reason for this is that nek checks explicitly for cbc='v  '
(v, followed by two spaces) in many locations.

The correct place for discriminating parameters is in the
arracy bc().

Normally I discriminate by geometry --- e.g., x < x0, or
something similar, occasionally involving the unit normals on
the face in question - as that can be a stronger discriminator.

Paul


On Fri, 16 Jul 2010, nek5000-users at lists.mcs.anl.gov wrote:

> Hi Aleks,
>
> Thank you very much for looking into this. I already have a question; I noticed that you marked several notes dealing with "RBC single inlet -- modify for other cases". I am assuming this means that you have one inlet that you want to recycle, but another inlet that you do not want to recycle, which just happens to be my case.
>
> Can I distinguish in the rea between the two by "v1 " and "v2 " without giving genmap any problems, and then modify the checks in the usr file accordingly? Also, the subroutine rescale_inflow mentions to modify for multiple inlets as well but I do not see where any modification could/needs to be done for it.
>
> - Michael
>
> ----- Original Message -----
> From: nek5000-users at lists.mcs.anl.gov
> To: nek5000-users at lists.mcs.anl.gov
> Sent: Friday, July 16, 2010 3:03:52 PM GMT -06:00 US/Canada Central
> Subject: [Nek5000-users] New Recycling BC based on interpolation
>
> Hi Michael and Markus,
>
> Here is a test case for an unsteady pipe flow with Michael's GambitPipe.rea file which sets inlet Recycling BCs based on interpolation from a cross-section downstream that you specify by a multiple of the inlet normal:
>
> http://www.mcs.anl.gov/~obabko/z4.tgz
>
>
> Let me know if you have any questions.
> Best,
> Aleks
>
>
>
>
> ----- Original Message -----
> From: nek5000-users at lists.mcs.anl.gov
> To: nek5000-users at lists.mcs.anl.gov
> Sent: Thursday, July 8, 2010 5:06:48 PM GMT -06:00 US/Canada Central
> Subject: Re: [Nek5000-users] New Recycling BC method?
>
>
>
>
>
> No worries, just checkin in to see how it was going, thanks for the update! Look forward to trying it out!
>
>
>
> - Michael
>
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