In which coordinates system is expressed velocity
 

Hi FOAMers !
I am currently working on a cylinder and trying to optimize the mesh in the domain that contains the cylinder.
I would like to minimize the error due to "mesh alignment". For that, I need to have the velocity on each cell and the coordinates of the center of each cell.
I made my mesh with the blockMesh utility.


In the file U in each temporal folder, I can see that I have the velocity vector expressed in a coordinates system.
My first question is : in which coordinate system is it expressed ? : Is it the local coordinate system of the cell ? Or every cell of each block defined in blockmesh dict has the same coordinate system ?

This is a problem for me since I have some edges which are curved. Then the coordinate system of each cell with rotate from the reference defined for a block in blockMeshDict.

I can give you more details if you need it

Velocity is always expressed in the global coordinates system.

Thanks a lot !