Hi,I have a question with symm
 

Hi,I have a question with symmetryPlane and hope to get some clarification here.

Take the flow around cylinder as example,e.g. the geometry of the cylinder flow ,first one in chapter 3 of the developer's guide.

There,The bottom boundary is used as symmetryPlane. my question is there are indeed two boundaries, one for the fluid,one for the cylinder.For the fluid part,I think the velocity gradient across the boundary is zero,for the cylinder part,I think the velocity there should be zero,is this right?

But now both the fluid part and cylinder part are assigned as symmetryPlane boundary conditions,could OpenFOAM know the difference of the two parts?

Thanks for any comments in advance.