24th Congress of International Council of the Aeronautical Sciences, 29 August-3, September 2004, Yokohama, Japan
Paper ICAS 2004-P.5

DISCRETE FREQUENCY SOUND RADIATION DUE TO FLUID FLOW OVER FLAT PLATES WITH ACOUSTICALLY NON-COMPACT CHORD

M. Aoki, K. Ishihara, T. Goto*
The University of Tokushima, Department of Mechanical Engineering 2-1, Minamijosanjima-cho, Tokushima, 770-8506, Japan; *Tottori University, Department of Mechanical Engineering Koyama, Tottori, 680-8552, Japan

Keywords: aerodynamic sound, velocity dependency, directivity, plate, edge shape

The intensity and directivity of discrete frequency sound generated from flat plates with various chord-to-thickness ratios were investigated by wind tunnel experiments and numerical analyses based on Lighthill's equation. As a practical criterion for compactness of a flat plate, we propose that the chord-to-wavelength ratio is approximately less than 0.3.

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