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Continuity in internal boundaries

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Hi,

I am trying to simulate a 3D air flow through a geometry formed by three different-shaped secuenced domains. the case is that when I run the study, the "solution" shows that there is a discontinuity in flow caused by the middle entity. this is evidenced by a zone of 0 velocity in this entity and pressure defined interfaces in the common boundaries between domain 1-2 and 2-3.

I choose this divided configuration because i'm trying to obtain an structured hexahedral mesh which is impossibl to obtain in other way

I've tried to use all the possible BC's in these boundaries including flow continuity (which appears enabled but the selection of pairs is disabled), I also tried by changing from union to assembly and viceversa, I even tried symmetry and open boundaries

in another discussion i've seen that sometimes these interior boundaries must be "activated"

does anybody knows why is this happening and what can i do to solve this problem

1 Reply Last Post 03.10.2010, 06:56 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 03.10.2010, 06:56 GMT-4
Hi
have you checked that you have the same dependent variables in all domains when using "assembly mode", if no you need to couple your BC by projection coupling variables, or weak constraints.

If yes, you need to get identity pairs up to link your boundaries, or use the methods of above

--
Good luck
Ivar
Hi have you checked that you have the same dependent variables in all domains when using "assembly mode", if no you need to couple your BC by projection coupling variables, or weak constraints. If yes, you need to get identity pairs up to link your boundaries, or use the methods of above -- Good luck Ivar

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