Water Wave Control by a Pitching Plate
Publication: Journal of Engineering Mechanics
Volume 123, Issue 8
Abstract
A new idea for controlling water waves is presented in this paper. A submerged pitching plate is suggested as an active wave controller, and its feasibility is theoretically investigated. The two-dimensional problem is formulated to deal with a fully submerged pitching plate fixed at its middle point scattering an incoming monochromatic wave, and the frequency of pitching is kept the same as that of the monochromatic wave. The method of matched eigenfunction expansions is used to analyze the amplitudes of reflected and transmitted waves with and without pitching. The variation of wave reflection and transmission versus the dimensionless water depth, length of plate, and its depth of submergence is discussed. The characteristics of the pitching plate are like a fixed plate and still very sensitive to its submerged depth and physical dimensions. The pitching plate has its high performance by controlling the phase and magnitude of pitching. Based on the linear wave theory, the wave force and moment are estimated, and their characteristics are illustrated in this paper. It is found that pitching has no influence on wave force but induces additional moment on the plate.
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References
1.
Leppington, F. G.(1972). “On the radiation and scattering of short surfaces waves. Part 1.”J. Fluid Mech., 56, 101–119.
2.
Liu, P. L.-F., and Iskandarani, M.(1991). “Scattering of short-wave groups by submerged horizontal plate.”J. Wtrwy., Port, Coast., and Oc. Engrg., ASCE, 117(3), 235–246.
3.
Milgram, J. H.(1970). “Active water-wave absorbers.”J. Fluid Mech., 42, 845–859.
4.
Neelamani, S., and Reddy, M. S.(1992). “Wave transmission and reflection characteristics of a rigid surface and submerged horizontal plate.”Oc. Engrg., 19(4), 327–341.
5.
Patarapanich, M.(1984a). “Maximum and zero reflection from submerged plate.”J. Wtrwy., Port, Coast., and Oc. Engrg., ASCE, 110(2), 171–181.
6.
Patarapanich, M.(1984b). “Force and moment on a horizontal plate due to wave scattering.”Coast. Engrg., 8, 279–301.
7.
Patarapanich, M., and Cheong, H.-F.(1989). “Reflection and transmission characteristics of regular and random waves from a submerged horizontal plate.”Coast. Engrg., 13, 161–182.
8.
Siew, P. F., and Hurley, D. G.(1977). “Long surface waves incident on a submerged horizontal plate.”J. Fluid Mech., 83, 141–151.
9.
Takaki, M. (1988). “Breakwater effect of a submerged horizontal plate.”Pacific Congr. on Marine Sci. and Technol. PACON 88, OST-9, Honolulu, Hawaii, 87–94.
10.
Yu, X., and Chwang, A. T.(1993). “Analysis of wave scattering by submerged circular disk.”J. Engrg. Mech., ASCE, 119(9), 1804–1817.
11.
Yu, X., and Chwang, A. T.(1994). “Water waves above submerged porous plate.”J. Engrg. Mech., ASCE, 120(6), 1270–1282.
Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 123 • Issue 8 • August 1997
Pages: 800 - 807
Copyright
Copyright © 1997 American Society of Civil Engineers.
History
Published online: Aug 1, 1997
Published in print: Aug 1997
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