ON THE FORMATION AND THE SHEDDING OF VORTEX-RING BEHIND A IMPULSIVELY STARTED SPHERES AT CONSTANT SPEED

Abstract

The flows and the process of the formation ans the shedding of the vortex-ring behind aimpulsively started spheres at aconstant speed in still water were photo-graphycally observed by the means of the electrolyses method. The permanent vortex-ring was confirmed at the Reynoulds number is higher than 24 by means of alminium dust method, however, as the results of this experiment, the flows behind a sphere was found to be perfectory laminer and no vortex-ring until Reynoulds number of 80 is reached. The formation of the vortex-ring and the hair-pin vortex-loop after partialy detachement of the vortex-ring was observed at Reynoulds number is about 600.