Table of Contents Author Guidelines Submit a Manuscript
International Journal of Rotating Machinery
Volume 1, Issue 3-4, Pages 187-197
http://dx.doi.org/10.1155/S1023621X95000066

The Effect of Surface Roughness of a Body in the High Reynolds Number Flow

Faculty of Engineering, Osaka Sangyo University, 3-1-1, Nakagaito, Daito, Osaka (574), Japan

Copyright © 1995 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In this paper, first, the principle, structures, operations, and performances of the cryogenic wind tunnel are described. By changing the pressure, temperature and velocity of gas a high Reynolds number flow (5×104<Re<107) can be obtained. From the research results, a high Reynolds number flow with comparatively low power, LN2 consumptions was attained. It was with Mach number independent of each other.

To show some examples of high Reynolds number flow, the effects of surface roughness and grooves on the surface of a cylinder on the flow are measured using models with various values of roughness and size. A model test of an airship was also conducted. With the high Reynolds number flow, the thickness of the boundary layer becomes thinner. Then the surface conditions of a body have great effect on the flow phenomena and on the drag of the body. Some attempts to reduce the drag of the body were shown.