boundary condition of lid driven cavity
 

On the top of the cavity, dirichlet boundary condition is usually used. (u=U,v=0) If neumann condtion for v is used instead of dirichlet condition(v=0), is it correct??:confused:

HI
 

Hi

I don't think you can specify the Naumann boundary condition, which says that the derivative of v component is zero indicating that the velocity in the first cell in the interior is equal to the velocity at the boundary, so u may no be enforcing the v=0 at the moving lid. Hence you can only use the Dirchlet boundary condition only.