Flow visualizations by the injected dye, smoke, bubbles, and scattering particles have been used widely in the investigstions on the flow pattern. In this paper, we adapt the flow visualization by the injected dye to measure the velocity of the flow in the space between two co-rotating disks. The primary motivation of this work is to simulate the magnetic disk storage system of computer, in which there are several engineering problems such as thermal non-uniformity, dynamic instability mainly induced by severe fluctuation of the flow. Circumferential velocity components were measured by the two continuous images having a fixed time interval ($0.303\sec$) of the injected dye in the flow, and the secondary flow configurations were detected by the scattering particles. The effects of the slided arm which corresponds to the magnetic head and its supporting arm of the computer disk system were also investigated.
It is observed that there exist circumferential velocity difference between the fluid and rotating disks at the region of R＞0.5 even in the steady state, and this would mean the existance of the recirculation eddies at that region.
본 논문에서는 회전하는 두 원판 사이에서의 유동에 대하여 염료에 의한 가시화로 유동방향의 속도를 측정하였고 부유입자를 이용하여 이차유동의 모습을 살펴보았다. 이 문제는 컴퓨터 하드디스크에서의 유동형태와 많은 유사성을 가지고 있다.
내부유동은 고정되어 있는 용기벽의 영향으로 정상상태(steady state)에서도 강체회전에 도달하지 못하며, 회전축에 가까운 영역에서는 확산에 의한 운동량의 전달이 상당함을 알 수 있었다.
본 연구에서 얻어진 유동특성을 바탕으로 하드디스크 설계를 위한 기초자료가 구축되었다.
