i solve axisymmetric Navier-Stokes equation with periodic boundary condition in 2D domain.

- my first question : how can i do to represent the solution in the rest of the domain in 2D . Example suppose i solve the equation in [0,2 ]
*[0,3 ] and i the have (u1, u2) in [0,2 ]*[0,3 ] we have the symmetric with axe y=0 . how can i do to have the solution (u1, u2) in the other sider [-2,0]*[0,3] , then export with paraview