[Nek5000-users] Linearised Navier-Stokes time-dependant base flow

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

Thanks a lot Paul.

That's pretty much the idea I had, but I just wanted to make sure.

Regards,
JC


2014-01-30 <nek5000-users at lists.mcs.anl.gov>:

>
> Dear JP,
>
> In perturb.f, the driver reads:
>
>       do jp=1,npert
>
>          if (nid.eq.0.and.igeom.eq.2) write(6,1) istep,time,jp
>    1     format(i9,1pe14.7,' Perturbation Solve:',i5)
>
>          call perturbv (igeom)
>
>       enddo
>
>       jp=0   ! set jp to zero, for baseline flow
>
>
> So, the appropriate discriminator in userbc would be:
>
>       if (jp.eq.0) then
>
>          ux=1
>
>       else
>
>          ux=0
>
>       end
>
> Best regards,
>
> Paul
>
>
>
>
>
> On Thu, 30 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:
>
>  Hi Nek's,
>>
>> I have a question regarding the linearised Navier-Stokes solver while the
>> underlying base flow is time-dependant. As far as I understand, one should
>> simply have to set param(31) = 1 to achieve this (and p31 = -1 for a
>> steady
>> state base flow). What about the boundary conditions however?
>>
>> For instant, I want to investigate the linear dynamics of perturbations
>> evolving onto a lid-driven cavity flow exhibiting a periodic limit cycle I
>> have computed. How could I impose in userbc:
>>
>> ux = 1
>> uy = 0
>> uz = 0
>>
>> for the periodic base flow time-evolution, and in the meantime:
>>
>> ux = 0
>> uy = 0
>> uz = 0
>>
>> for the perturbation?
>>
>> Cheers,
>> JC
>>
>> --
>> Jean-Christophe Loiseau
>> Homepage <https://sites.google.com/site/loiseaujc/>
>>
>>  _______________________________________________
> Nek5000-users mailing list
> Nek5000-users at lists.mcs.anl.gov
> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>



-- 
Jean-Christophe Loiseau
Homepage <https://sites.google.com/site/loiseaujc/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/nek5000-users/attachments/20140130/9c8777f2/attachment.html>