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BACKING='EXPOSED' not working with GEOM and multi-mesh
@marcosvanella is this a known issue? We need to get this in the queue of stuff to fix. The case where I noticed this is here:
/home/rmcdermo/GitHub/FireModels_rmcdermo/fds/Validation/Lattimer_Tilted_Wall/FDS_Input_Files/Lattimer_50_kW_35_degree_fine.fds
Did the model error out for you or did it output a warning? When I ran the case with 6.8 it flagged a warning but did start.
Fire Dynamics Simulator
Current Date : June 1, 2023 14:38:58 Revision : FDS-6.8.0-0-g886e009-release Revision Date : Tue Apr 18 07:06:40 2023 -0400 Compiler : Intel ifort 2021.7.0 Compilation Date : Tue 04/18/2023 03:22 PM
MPI Enabled; Number of MPI Processes: 1 OpenMP Disabled
MPI version: 3.1 MPI library version: Intel(R) MPI Library 2021.9 for Windows* OS
Job TITLE : Surface temperature on slopped wall Job ID string : Lattimer_50_kW_35_degree_fine
WARNING: BACK CFACE search, other mesh NOM not equal to working mesh NM. NM= 4 , NOM and other cell IIO,JJO,KKO= 10 2 4 7 , intersection pt= -0.182223317628544 -0.302500000000000 0.260241867853140 WARNING: BACK CFACE search, other mesh NOM not equal to working mesh NM. NM= 4 , NOM and other cell IIO,JJO,KKO= 10 2 5 7 , intersection pt= -0.182223317628544 -0.293750000000000 0.260241867853140
WARNING: BACK CFACE search, other mesh NOM not equal to working mesh NM. NM= 10 , NOM and other cell IIO,JJO,KKO= 4 31 52 8 , intersection pt= -0.217084998428775 0.293750000000000 0.265745959190895 WARNING: BACK CFACE search, other mesh NOM not equal to working mesh NM. NM= 10 , NOM and other cell IIO,JJO,KKO= 4 31 53 8 , intersection pt= -0.217084998428776 0.302500000000000 0.265745959190895 Time Step: 1, Simulation Time: 0.02 s Time Step: 2, Simulation Time: 0.03 s Time Step: 3, Simulation Time: 0.05 s
Just the warning. But I take it to mean that EXPOSED is not working in this case and that some other backing condition is being applied? In general, I think this is something we need to discuss. I think it should basically function like the OBST with similar limitations.
There is no exchange of exposed CFACES from mesh to mesh. There is for WALL cells, but not CFACE.
I think this is something we should add. If I create an OBST that is one cell thick with an exposed backing. And then turn that OBST to a GEOM, I think we should be able to get the same functionality. Not saying it is trivial. But I think this should be on the list for v7.
Kevin is right. The back intersection point is computed from the input geometry (all MPI processes have it) but the infra to exchange these intersection points, figure out the back cfaces in other meshes, and exchange information of these among processes hasn't been developed. Currently, it will use 'VOID' in these cases.
