[petsc-users] PETScFE Point Source

[Stefano Zampini]

Il Ven 13 Apr 2018, 21:27 Sanjay Govindjee <s_g at berkeley.edu> ha scritto:

> Wouldn't it make the most sense to do it in a variationally consistent
> manner
>
> rhs_a = int{ N_a delta(x - x_o) }
>
> where x_o is the location of the point source?
>


This is what I meant. However, the current callbacks for residual
evaluation in PetscDS do not allow to do it.


> -sanjay
>
> On 4/13/18 7:46 PM, Matthew Knepley wrote:
>
> On Fri, Apr 13, 2018 at 1:40 PM, Robert Walker <rlwalker at usc.edu> wrote:
>
>> Hello,
>>
>> Is there an example of application of a point source in one of the
>> tutorial  PETScFE style examples? Ideally this would be some point on the
>> interior, and not necessarily on a boundary.
>>
>> Thanks, and apologies in advance if this is a stupid question,
>>
>
> No, good question. You would have to decide what that meant in FEM terms.
> All the internal integrals are done
> with quadrature. So putting the source at a quadrature point would work,
> although its a little difficult to know where
> they will be. You could smooth it out a little, and check coordinates in
> the forcing function. Last, you could check
> for a "close enough" quadrature point and put it there. I think making a
> slightly extended source is usually best.
>
>   Thanks,
>
>      Matt
>
>
>> Robert
>>
>>
>> Robert L. Walker
>> MS Petroleum Engineering
>> Mork Family Department of Chemicals and Materials Sciences
>> University of Southern California
>> ----------------------------------------------
>> Mobile US: +1 (213) - 290 -7101
>> Mobile EU: +34 62 274 66 40
>> rlwalker at usc.edu
>>
>
>
>
> --
> What most experimenters take for granted before they begin their
> experiments is infinitely more interesting than any results to which their
> experiments lead.
> -- Norbert Wiener
>
> https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/%7Emk51/>
>
>
> --
> -------------------------------------------------------------------
> Sanjay Govindjee, PhD, PE
> Horace, Dorothy, and Katherine Johnson Professor in Engineering
>
> 779 Davis Hall
> University of California
> Berkeley, CA 94720-1710
>
> Voice:  +1 510 642 6060
> FAX:    +1 510 643 5264s_g at berkeley.eduhttp://faculty.ce.berkeley.edu/sanjay
> -------------------------------------------------------------------
>
> Books:
>
> Engineering Mechanics of Deformable Solidshttp://amzn.com/0199651647
>
> Engineering Mechanics 3 (Dynamics) 2nd Editionhttp://amzn.com/3642537111
>
> Engineering Mechanics 3, Supplementary Problems: Dynamics http://www.amzn.com/B00SOXN8JU
>
> NSF NHERI SimCenterhttps://simcenter.designsafe-ci.org/
> -------------------------------------------------------------------
>
>
>
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