2013 Fiscal Year Final Research Report

Investigation on the Large-Scale Vortex Structures of the Complex Flow induced by Rotating Disks in a Non-Axisymmetric Enclosure

Research Project

Project/Area Number	24860041
Research Category	Grant-in-Aid for Research Activity Start-up
Allocation Type	Single-year Grants
Research Field	Fluid engineering
Research Institution	Kobe University
Principal Investigator	SHIRAI KATSUAKI 神戸大学, 自然科学系先端融合研究環, 助教 (00634916)
Project Period (FY)	2012-08-31 – 2014-03-31
Keywords	流体工学 / 流れの可視化 / 屈折率整合 / 画像計測 / 情報ストレージ機器 / ハードディスクドライブ / 3次元乱流 / 流体関連振動
Research Abstract	The present study aimed to clarify the onset mechanism of flow-induced vibration encountered at the flow induced by rotating disks. An experimental model was built taking into account of the non-axisymmetric shroud opening and the arm for reading/writing data existing in a hard disk drive. The complex flow structure was investigated through flow visualization under a matched refractive-index condition where the refractive index of the working fluid coincided with that of the transparent experimental flow model. In particular, the investigation focused at the polygonal flow structure formed by large-scale vortices, flow stagnation in the shroud opening and the arm wake. As a result, it was confirmed that the polygonal structure can be maintained even under the combination of the axisymmetric enclosure with the arm insertion and that the flow exhibits strong three-dimensionality influenced by the arm insertion.