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Interaction of waves with two-dimensional obstacles: a relation between the radiation and scattering problems

Published online by Cambridge University Press:  29 March 2006

J. N. Newman
Affiliation:
Department of Ocean Engineering, Massachusetts Institute of Technology, Cambridge

Abstract

A relation connecting the reflexion and transmission coefficients for scattering of water waves by a fixed body with the far-field radiated waves due to forced motions of the same body is derived. Two alternative derivations are given, including a simple argument based on the analysis of an appropriate linear superposition of the two problems, and a more formal application of Green's theorem to the two potentials. For bodies with horizontal symmetry, the transmission and reflexion coefficients are related to the phase angles of the far-field radiated waves associated with symmetric and antisymmetric forced motions of the body. Some general conclusions follow for arbitrary symmetric bodies, and these are verified in specific cases by comparison with existing solutions. The applicability of these relations to other types of wave problem is noted.

Type
Research Article
Copyright
© 1975 Cambridge University Press

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References

Dean, W. R. 1948 On the reflexion of surface waves by a submerged cylinder. Proc. Camb. Phil. Soc. 44, 483491.Google Scholar
Drazin, P. G. & Moore, D. W. 1967 Steady two-dimensional flow of fluid of variable density over an obstacle. J. Fluid Mech. 28, 353370.Google Scholar
Evans, D. V. 1970 Diffraction of water waves by a submerged vertical plate. J. Fluid Mech. 40, 433451.Google Scholar
Evans, D. V. 1974 A note on the total reflexion or transmission of surface waves in the presence of parallel obstacles. J. Fluid Mech. 67, 465472.Google Scholar
Evans, D. V. & Morris, C. A. N. 1972a Complementary approximations to the solution of a problem in water waves. J. Inst. Math. Appl. 10, 19.Google Scholar
Evans, D. V. & Morris, C. A. N. 1972b The effect of a fixed vertical barrier on obliquely incident surface waves in deep water. J. Inst. Math. Appl. 9, 198204.Google Scholar
Havelock, T. H. 1929 Forced surface waves on water. Phil. Mag. 8, 569576.Google Scholar
Kotik, J. 1963 Damping and inertia coefficients for a rolling or swaying vertical strip. J. Ship Res. 7 (2), 1923.Google Scholar
Mei, C. C. & Chen, H. S. 1974 A hybrid finite element method for the linearized theory of steady free-surface flows. Part I. The theoretical basis. To be published.
Newman, J. N. 1962 The exciting forces on fixed bodies in waves. J. Ship Res. 6, 3, 1017.Google Scholar
Newman, J. N. 1965 Propagation of water waves past long two-dimensional obstacles. J. Fluid Mech. 23, 2329.Google Scholar
Newman, J. N. 1974 Interaction of water waves with two closely spaced vertical obstacles. J. Fluid Mech. 66, 97106.Google Scholar
Ogilvie, T. F. 1963 First- and second-order forces on a cylinder submerged under a free surface. J. Fluid Mech. 16, 451472.Google Scholar
Ogilvie, T. F. 1973 The Chertock formulas for computing unsteady fluid dynamic force on a body. Z. angew. Math. Mech. 53, 573582.Google Scholar
Ursell, F. 1950 Surface waves on deep water in the presence of a submerged circular cylinder. Proc. Camb. Phil. Soc. 46, 141152.Google Scholar
Wehausen, J. V. & Laitone, E. V. 1960 Surface waves. In Handbuch der Physik, vol. 9, pp. 446778. Springer.