Oscillating flow about perforated cylinders

Abstract

Circular cylinders of various sizes and perforations were subjected to sinusoidally-oscillating flow in a large U-shaped water tunnel. The force- transfer coefficients (drag and inertia) were determined in the range of Keulegan-Carpenter numbers (K) from about 1 to 40. The results have shown that the effect of the perforations is to decrease the inertia coefficient and to increase the drag coefficient. Thus, perforated cylinders are very efficient dampers and may be used into increase or control the damping of cables and large structures in the ocean environment.