TELEMAC-MASCARET Forum: Limit height of sumbmerged object (1/1)

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TOPIC: Limit height of sumbmerged object

Limit height of sumbmerged object 4 years 11 months ago #35004

SDAC

Hello,

I have an object that uniformly extends up through the flow layers. It's represented by applying head losses at the nodes on the vertical Z(I3D).

It has a max height (1.5m). Head losses should not be applied above this height. However, when I have flows that exceed this height head losses aren't applied on any of the nodes above or below the max height.

My code is below. Does anyone know why this is happening?
The code is simple, and should say that head losses are applied for nodes only below the max height:

        DO IPLAN = NPLAN-29,NPLAN !for layers at that node
        I3D = I1+NPOIN2*(IPLAN-1) !get the 3D node IDs for nodes I1

!height application
        IF (Z(I3D).LE.SEMX)THEN   !if node height < max height (SEMX) apply h.loss

         NORM =SQRT(UN3%R(I3D)**2+VN3%R(I3D)**2+WN3%R(I3D)**2)
         S1U%R(I3D)=0.5D0*A*CDV*RF*NORM
         S1V%R(I3D)=0.5D0*A*CDV*RF*NORM
         S1W%R(I3D)=0.5D0*A*CDV*RF*NORM
	   END IF
        END DO
       END IF
      END DO

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Limit height of sumbmerged object 4 years 11 months ago #35012

SDAC	I ran some checks and I think the code is fine, and the issue comes from partitioning on my cluster. When I partition <= 10, then the results look fine. If it's >10 then I get missing objects. Is this possible? The code between successful and problematic runs is the same. The only thing that changes is the flow parameters, but this is fine with low partitioning.
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Limit height of sumbmerged object 4 years 11 months ago #35015

c.coulet OFFLINE Moderator Posts: 3722 Thank you received: 1031	Look strange! Colld be good to have the entire case to investigate why parallel computation with more than 10 processors doesn't work Regards
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Limit height of sumbmerged object 4 years 11 months ago #35017

SDAC	I can't imagine how the partitioning can cause such an issue, however it's the only change that seems to have an effect. My knowledge on parallelism isn't great, but possibly related to model set-up etc. I can email my case file over?
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Limit height of sumbmerged object 4 years 11 months ago #35018

Sokolov OFFLINE Junior Boarder Posts: 38 Thank you received: 13	I also have similar problem. Model works great up to 40 CPUs and crashes on 41 - 48. Telemac3d v8p0r3.
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Limit height of sumbmerged object 4 years 11 months ago #35019

c.coulet
OFFLINE
Moderator
Posts: 3722
Thank you received: 1031

Same recommendation.
If you're able to share your model, we could try on our side and see if we could reproduce your problem.
If we could reproduce, people in charge of developments could try to analyse the problem to solve it.
Sometimes it's an indicator of an unseen problem
Sometimes this just shows a local numerical problem (potentialy linked to the mesh) which appear due to the partitioning particularly if the lilmit between submodels is near the problem.

Christophe

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