TITLE:
Experimental Study on Vortex Growth during the Early Development of Rotating Disks
AUTHORS:
Hiroyuki Furukawa, Takeomi Yamazaki
KEYWORDS:
Rotating Disk, Experimental Study, Flow Instability, Non-Uniqueness
JOURNAL NAME:
World Journal of Mechanics,
Vol.12 No.3,
March
31,
2022
ABSTRACT: In
previous studies, the effects of radial clearance on the flow of a rotating
disk in a cylindrical vessel have been investigated by using rotating disks of
different shapes. As a result, different flow phases were observed in each disk due to the difference in disk dimensions. In
this study, we focus on the end-face effect and conduct experiments to
visualize the vortex growth process and elucidate the generation mechanism of
the vortex structure. From the experiment results, 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 ts. When Re
= 4000, the rotational ascent time ts = 0, 2, 7, and 8
was stable at regular 4-cells, while the others were finally stable in regular
2-cells. This study revealed the influence of the acceleration of the rotating
disk on the non-unique flows in the cylindrical casing.