In this paper the numerical method with a zonal embedded grid system for an incompressible flow within a semi-circular container is presented. The algorithm is validated by its application to some typical flow models including the spin-up flow inside a semi-circular geometry. Flow visualization for the spin-up flows was used by PIV. The results show that at high Reynolds numbers the cyclonic cell at the left-hand side region moves along the circular wall and merges with the cell at the right-hand side region.