An experimental study of a flow field generated by a rotating cylinder on a plane moving at free stream velocity

Title & Authors
An experimental study of a flow field generated by a rotating cylinder on a plane moving at free stream velocity
Park, Un-Jin;

Abstract
The flowfield generated by a 2-D rotating cylinder on a plane moving at freestream velocity was experimentally investigated in a wind tunnel to simulate aerodynamic characteristics of rotating wheels of an automobile. In the flowfield around a rotating cylinder at 3*10$\small{^{3}}$ < Re$\small{_{d}}$<8*10$\small{^{3}}$, unique mean flow and turbulence characteristics were confirmed by hot-wire measurements as well as frequency analysis, which was supported by flow visualization. In the vicinity of a rotating cylinder, a unique turbulence structure on .root.over bar u'$\small{^{2}}$ profiles was formed in hump-like shape at 1 < y/d < 3. A peak frequency which characterized the effect of a rotating cylinder had the same value of the rotation rate of a cylinder. In case of cylinder rotation, the depths of mean velocity -defect and turbulent-shear regions were thickened by 20-40% at 0 < x/d < 10 compared with the case of cylinder stationary. Far downstream beyond x/d > 10, the flowfield generated by a rotating cylinder showed self-similarity in the profiles of mean velocity and turbulence quantities. The effect of a rotating cylinder was independent of its rotation rate and Reynolds number in the measurement range.
Keywords
2-D Rotating Cylinder;Moving-Belt System;Turbulent Shear Flow;Flow over an Obstacle;Flow Visualization;Hot-Wire Measurement;Aerodynamic Characteristics of Automobiles;
Language
Korean
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