Separation in time-dependent flow

Abstract

The angular motion of separation points on a smooth cylinder immersed in a sinusoidally oscillating flow has been determined experimentally through the use of a U-shaped water tunnel, a special differential pressure probe, and a data acquisition system. The results have been compared with those obtained previously by Grass and Kemp for a single amplitude of oscillation through the use of flow visualization. The results have shown that the separation points undergo large angular excursions during a given cycle, the degree of excursion depending on the Reynolds number and the Keulegan-Carpenter number. The separation data obtained in this exploratory investigation will form the basis of future numerical analysis of oscillating flow about cylinders.