[Nek5000-users] PN/PN and usrdiv

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

I'll check into it this afternoon...

Paul


On Fri, 9 Apr 2010, nek5000-users at lists.mcs.anl.gov wrote:

> Paul,
>
> I think know why. We should not multiply usrdiv with the mass matrix
>
> so just replace
>
> call col3 (h1,usrdiv,bm1,ntot1)
> call add2 (qtl,h1,ntot1)
>
> by
>
> call add2(qtl,usrdiv,ntot1)
>
> at the beginning of plan4().
>
> Unfortunately I don't have the time to test this fix.
>
> Let me know if this works for you.
> Stefan
>
>
>
> On Apr 9, 2010, at 4:21 PM, nek5000-users at lists.mcs.anl.gov wrote:
>
>>
>> Yes - I just checked and it's indeed not doing anything for
>> Pn-Pn.
>>
>> I'll get to this by the end of the afternoon... should take
>> minimal effort to repair I think.
>>
>> Sorry about this Markus.
>>
>> Paul
>>
>>
>> On Fri, 9 Apr 2010, nek5000-users at lists.mcs.anl.gov wrote:
>>
>>> I have not used this feature for a while but usrdiv is used in plan4().
>>>
>>> --- snip plan4.f ---
>>> 40       ! add user defined divergence to qtl
>>> 41       call col3 (h1,usrdiv,bm1,ntot1)
>>> 42       call add2 (qtl,h1,ntot1)
>>> --- snip plan4.f
>>>
>>>
>>> Stefan
>>>
>>>
>>> On Apr 9, 2010, at 1:49 PM, nek5000-users at lists.mcs.anl.gov wrote:
>>>
>>>> Hi,
>>>>
>>>> since I switched the pressure scheme from P_N/P_N-2 to PN/PN, as recommended by an earlier email, I have divergence trouble (simulation crashes) at the outflow, were a stabilization technique as in examples "peris" and "jet" is in place (adding divergence via usrdiv).
>>>> I spent a long time trying to fix this (several test runs with increased outflow normal element length, increased divergence magnitude, mesh deformation to nozzle shape, which avoids crashing but has an adverse effect on the upstream flow,...) but I am becoming suspicious that usrdiv is just not used in PN/PN.
>>>> Is that true? If so, how to fix it?
>>>>
>>>> Thanks,
>>>> Markus
>>>>
>>>> _______________________________________________
>>>> Nek5000-users mailing list
>>>> Nek5000-users at lists.mcs.anl.gov
>>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>>>
>>> _______________________________________________
>>> Nek5000-users mailing list
>>> Nek5000-users at lists.mcs.anl.gov
>>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>>>
>> _______________________________________________
>> Nek5000-users mailing list
>> Nek5000-users at lists.mcs.anl.gov
>> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>
> _______________________________________________
> Nek5000-users mailing list
> Nek5000-users at lists.mcs.anl.gov
> https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users
>