wondering about patch.nf() and mesh.Sf().boundaryField()[patchID]

codder · July 24, 2014, 14:08

Ultra confused by simple question...

Is the vectorField result of the following two expressions always identical ?

Within a patch I can access an ordered field of face normals:

Code:

patch.nf()

For that same patch with ID "patchID" but now within a solver, I can get face normals using:

Code:

mesh.Sf().boundaryField()[patchID] / mesh.magSf().boundaryField()[patchID]

I.e., are both these vectorFields ordered in the same sequence ??

I would like it very much if they are !! Thank you

vigneshTG · October 31, 2014, 05:08

Dear Eric,

I also have the same doubt, did you find out the answer ? One more thing, can you tell me, how to access the normal vectors of a patch using patch.nf() ?

chriss85 · October 31, 2014, 08:14

They should have the same order as far as I know (but differences between single core and decomposed mesh may exist). Incase you want to access the cells next to the boundary, you will need a different index which can be found with the faceCells() function.

codder · October 31, 2014, 14:12

Sorry for not updating to this thread earlier. I'm not 100% sure (I didn't track down the C++) but having assumed them same for awhile I've never gone wrong.

So yes they share the same ordering.

July 24, 2014, 14:08	wondering about patch.nf() and mesh.Sf().boundaryField()[patchID]	#1
codder Member Eric Bryant Join Date: Sep 2013 Location: Texas Posts: 44 Rep Power: 13	Ultra confused by simple question... Is the vectorField result of the following two expressions always identical ? Within a patch I can access an ordered field of face normals: Code: patch.nf() For that same patch with ID "patchID" but now within a solver, I can get face normals using: Code: mesh.Sf().boundaryField()[patchID] / mesh.magSf().boundaryField()[patchID] I.e., are both these vectorFields ordered in the same sequence ?? I would like it very much if they are !! Thank you randolph likes this.

October 31, 2014, 05:08		#2
vigneshTG Member Vignesh Join Date: Oct 2012 Location: Darmstadt, Germany Posts: 66 Rep Power: 14	Dear Eric, I also have the same doubt, did you find out the answer ? One more thing, can you tell me, how to access the normal vectors of a patch using patch.nf() ? __________________ Thanks and Regards Vignesh

October 31, 2014, 14:12	yes it's true!	#4
codder Member Eric Bryant Join Date: Sep 2013 Location: Texas Posts: 44 Rep Power: 13	Sorry for not updating to this thread earlier. I'm not 100% sure (I didn't track down the C++) but having assumed them same for awhile I've never gone wrong. So yes they share the same ordering.

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October 31, 2014, 08:14		#3
chriss85 Senior Member Join Date: Oct 2013 Posts: 397 Rep Power: 19	They should have the same order as far as I know (but differences between single core and decomposed mesh may exist). Incase you want to access the cells next to the boundary, you will need a different index which can be found with the faceCells() function.