Vortex Growth during the Early Development of Rotating Disks: A Experimental Study

Abstract

Using rotating disks of various forms, the effects of radial clearance on the flow of a rotating disk in a cylindrical vessel have been examined in earlier studies. Due to the disparity in disk diameters, various flow phases were seen in each disk. In this work, the end-face effect is the primary emphasis, and experiments are conducted to illustrate the vortex growth process and clarify the mechanism generating the vortex structure. Based on the findings of the experiment,at Re = 4000, 7000, and 9000, four types of vortex flow modes appeared in the vortex development process. However, at Re = 4000, only regular 2-cells and regular 4-cells appeared, and at Re=9000, only mutated 2-cells and mutated 3-cells appeared. In addition, it was found that only one type appeared depending on the rotational ascent time t_s. When Re = 4000, the rotational ascent time t_s = 0, 2, 7, and 8 was stable at regular 4-cells, while the others were finally stable in regular 2-cells. This research investigated the effect of rotating disk acceleration on non-unique flows in a cylindrical casing.