Unsteady Flow in a Cavity Induced by An Oscillatory External Flow

J. Ocean Eng. Technol. 1996;10(3):105-116.

외부유동에 의한 캐버티 내의 비정상 유동특성

서용권,박준관,문종춘

동아대학교 기계공학과,동아대학교,동아대학교 생산기술연구소

Keywords: cavity, unsteady flow, mass transport, residual flow, asymmetric flow pattern

핵심용어: 캐버티, 비정상 유동, 물질전달, 잔류유동, 비대칭 유동 양상

Abstract

In this paper, we report the experimental results for the flow pattern and the material transport around a cavity subject to a sinusoidal external flow at the far region to ward the open side of the cavity. A tilting mechanism is used to generate a oscillatory flow inside a shallow rectangular container having a cavity at one side. The surface flow visualization is performed to obtain the unsteady behavior of vortices generated at two edges situated at the entrance of the cavity. It was found that at the period 4.5 sec., the behavior of the vortices is asymmetric, and there exists a steady residual flow in the cavity. The bottom flow patterns are also visualized. There are two regions outside of the cavity where the bottom fluid particles concentrate. The material transport in this flow model is very peculiar; fluid particles in the cavity flows outward through the passage along the walls starting from the edges, and particles in the outer region approach the cavity from the central region.