Fluid dynamic characteristics of the flow over an array of large roughness elements

Author

Garimella, Suresh V. ; Eibeck, Pamela A.

Author_Institution

Dept. of Mech. Eng., Wisconsin Univ., Milwaukee, WI, USA

fYear

1992

fDate

5-8 Feb 1992

Firstpage

102

Lastpage

109

Abstract

Flow visualization and measurements of velocity and turbulence intensity using laser Doppler velocimetry are used to investigate separation and reattachment processes in the flow over an array of protruding elements mounted on the bottom wall of a rectangular water channel. The concept of an array shear layer is introduced to demarcate the region of influence over which the resistance of the array retards the flow. Flow separation at the leading edge of the elements is documented. The confined or interacting nature of the flow in the cavities between elements is established as a function of element spacing. The reattachment length downstream of the element varies from 4 to 1.5 element heights, decreasing both with an increase in Reynolds number and a decrease in channel height

Keywords

channel flow; external flows; flow separation; flow visualisation; shear turbulence; velocity measurement; Reynolds number; array of protruding elements; array shear layer; cavities between elements; channel height; element spacing; laser Doppler velocimetry; reattachment length downstream; reattachment processes; rectangular water channel; velocity measurement flow reattachment; Fluid dynamics; Fluid flow measurement; Mechanical engineering; Mechanical variables measurement; Optical arrays; Rough surfaces; Surface roughness; Thermal management; Velocity measurement; Visualization;

fLanguage

English

Publisher

ieee

Conference_Titel

Thermal Phenomena in Electronic Systems, 1992. I-THERM III, InterSociety Conference on

Conference_Location

Austin, TX

Print_ISBN

0-7803-0503-5

Type

conf

DOI

10.1109/ITHERM.1992.187746

Filename

187746