Calculation of Two-Dimensional Potential Cascade Flow Using Finite Area Methods

A rapid and accurate numerical method is presented for the calculation of two-dimension al potential flow in cascades. The integral form of continuity is approximated over finite areas in the physical plane, allowing the grid flexibility required by the periodicity, turning, thickness, and stagger of cascades of practical interest, and yielding second-order accuracy on appropriate meshes. Excellent agreement between predictions and analytic or measured results are shown for subsonic and transonic test cases. A model problem stability analysis supports the experimental observation that the procedure is unconditional ly stable for subsonic flow and conditionally stable for transonic flow.