OSCILLATING INVISCID FLOW OVER ELLIPTIC CYLINDERS WITH FLAT PLATES AND CIRCULAR-CYLINDERS AS SPECIAL CASES

The problem of oscillating inviscid flow over an elliptic cylinder is studied for various angles of attack. The flow is incompressible and two-dimensional and the oscillations are harmonic. The flow direction is always normal to the cylinder axis and oscillations are only allowed in the magnitude of the free stream velocity. The study focuses on the hydrodynamic forces acting on the cylinder as well as the surface pressure distribution and their time variation. The parameters involved are the cylinder axis ratio, the angle of attack and the Strouhal number. The variables are normalized in such a way that the solutions for the problems of oscillating flow over flat plates and circular cylinders can be easily obtained as special cases Analytical expressions are given for the drag coefficient, the lift coefficient, and the surface pressure distribution and their variation with time. Similar analytical expressions are given for the special cases of circular cylinders and inclined flat plates in oscillating inviscid flows.