Interaction between Turbulent Boundary Layer and Wake Behind an Elliptic Cylinder at Incidence

- Journal title : Transactions of the Korean Society of Mechanical Engineers B
- Volume 24, Issue 7, 2000, pp.976-983
- Publisher : The Korean Society of Mechanical Engineers
- DOI : 10.22634/KSME-B.2000.24.7.976

Title & Authors

Interaction between Turbulent Boundary Layer and Wake Behind an Elliptic Cylinder at Incidence

Choi, Jae-Ho; Lee, Sang-Joon;

Choi, Jae-Ho; Lee, Sang-Joon;

Abstract

The flow characteristics around an elliptic cylinder with axis ratio of AR=2 located near a flat plate were investigated experimentally to study the interaction between the cylinder wake and the turbulent boundary layer. The pressure distributions on the cylinder surface and on the flat plate were measured with varying the angle of attack of the cylinder. In addition, the velocity profiles of wake behind the cylinder were measured using a hot-wire anemometry As the angle of attack increases, the location of peak pressure on the windward and leeward surfaces of the cylinder moves toward the rear and front of the cylinder, respectively. At positive angles of attack, the position of the minimum pressure on the flat plate surface is moved downstream, but it is moved upstream at negative angles of attack. With increasing the angle of attack, the vortex shedding frequency is gradually decreased and the critical angle of attack exists in terms of the gap ratio. By installing the elliptic cylinder at negative angle of attack, the turbulent boundary layer over the flat plate is disturbed more than that at positive incidence. This may be attributed to the shift of separation point on the lower surface of the cylinder due to the presence of a ground plate nearby.

Keywords

Elliptic Cylinder;Turbulent Boundary Layer;Angle of Attack;Ground Effect;

Language

Korean

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