The flow around a flat plate acting in rotational oscillation. Numerical analysis by discrete vortex model.

The discrete vortex model with conformal mapping method has been applied to analyze the flow around the flat plate acting in rotational oscillation about the front end of a plate in a uniform flow. Numerical conditions are determined by comparing with the result of flow visualization already reported.. Then, numerical calculations are performed for various nondimensional frequencies (ratio of circumferential velocity at end of plate to uniform flow velocity) of more than 0.1 and amplitudes. Vortex patterns and unsteady forces are obtained. As a result, a thrust is generated on the plate for nondimensional frequencies of more than 0.1 by this oscillation. The thrust on the plate increases as the amplitude becomes large under the condition of these frequencies.