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Boundary condition coordinate system in 3D CFD model

Posted Oct 2, 2012, 7:56 p.m. EDT Computational Fluid Dynamics (CFD) Version 4.3 3 Replies

Tim Brox
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Hi Folks,

I would like to change the coordinate system for the velocity of a sliding wall boundary condition in a 3D CFD model (in COMSOL 4.3).

Thanks,
Tim
3 Replies Last Post Dec 7, 2012, 3:00 a.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Oct 3, 2012, 2:55 a.m. EDT
Hi

COMSOL works only in cartesian (and 2D-axi) but you can add your own coordinate systems, and many BC or domain physics properties will then propose to select the desired intput coordinate system to refer to.

But for the postprocessing everything is in cartesian, so you must type out the equations, or use your Defined coordinate system to reexpress the variables the way you want them

--
Good luck
Ivar
Hi COMSOL works only in cartesian (and 2D-axi) but you can add your own coordinate systems, and many BC or domain physics properties will then propose to select the desired intput coordinate system to refer to. But for the postprocessing everything is in cartesian, so you must type out the equations, or use your Defined coordinate system to reexpress the variables the way you want them -- Good luck Ivar
Abbie
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Posted: 1 decade ago Dec 7, 2012, 1:39 a.m. EST
Hi Ivar,

Because of COMSOL works in Cartesian coordinate, so the user-defined variables have to be in Cartesian coordinate even if i am working on a half-ellipse in a 2D axi study, is it?

Thanks!
Hi Ivar, Because of COMSOL works in Cartesian coordinate, so the user-defined variables have to be in Cartesian coordinate even if i am working on a half-ellipse in a 2D axi study, is it? Thanks!
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Dec 7, 2012, 3:00 a.m. EST
Hi

I would say yes and no ;) you can define your own "Definitions" coordinate systems, but indeed you need to get down to the COMSOL coordinates at least, and back to yours in the results section

Check the equations and new variables to help you from the user defined coordinate systems

--
Good luck
Ivar
Hi I would say yes and no ;) you can define your own "Definitions" coordinate systems, but indeed you need to get down to the COMSOL coordinates at least, and back to yours in the results section Check the equations and new variables to help you from the user defined coordinate systems -- Good luck Ivar

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