NUMERICAL AND EXPERIMENTAL INVESTIGATIONS OF THE FLOW OVER A DISK UNDERGOING UNSTEADY MOTION

Abstract

The unsteady wake of a disk subjected to deceleration after starting from rest has been investigated both experimentally and numerically. Experiments were conducted in water for Reynolds numbers of 8 300 and 12 400. The flow field remained axisymmetric throughout the short duration of the test after the start-up. A numerical simulation has been performed using the axisymmetric vortex method developed by one of the authors. The time-dependent global wake structure and the drag time history were compared and very good agreement was shown between the experiment and the numerical simulation.