Neumann Boundary Conditions

1

I am solving a system of PDEs on the unit square, where one of the unknowns, a vector field q, must satisfy the boundary condition.
q⋅n=1
Does anybody find a solution about the boundary condition?THANK YOU.

2

That depends on your PDE. Note that this is not a Neumann condition, as a Neumann condition would involve the normal component of the gradient of the field q

3

n is normal vector to the surface. q is fluid mass flux vector.1 is the fluid mass flux.Ido not know how to apply boundary condition like this.