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Generation of an axisymmetrical acoustic pulse by a deformable sphere

Published online by Cambridge University Press:  24 October 2008

G. E. Tupholme
Affiliation:
School of Mathematics and Physics, University of East Anglia, Norwich

Abstract

In this paper we consider sound pulses generated in the fluid outside an impermeable sphere by axisymmetrical time-dependent deformations of the sphere. Following an account of some analytic techniques applicable to this class of problems, a detailed study is made of the case in which the movement of the spherical boundary is confined to a cap of angle α (0 < α < π). In this case a rather complicated pattern of wavefronts develops consisting of a direct (spherical) wavefront, diffracted wave-fronts and a toroidal wavefront having as its centre circle the edge of the cap. Approximations to the velocity potential near the various wavefronts are obtained and some numerical results are given.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1967

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References

REFERENCES

(1)Hopkins, H. G.Progress in solid mechanics, vol. I (eds. Sneddon, I. N. and Hill, R.), (North-Holland; Amsterdam, 1960), 85164.Google Scholar
(2)Eringen, A. C.Quart. J. Mech. Appl. Math. 10 (1957), 257270.CrossRefGoogle Scholar
(3)Chadwick, P. and Trowbridge, E. A.Proc. Cambridge Philos. Soc. 63 (1967), 11771187.CrossRefGoogle Scholar
(4)Watson, G. N.Proc. Roy. Soc. Ser. A 95 (1918), 8399.Google Scholar
(5)Friedlander, F. G.Sound pulses (Cambridge University Press, 1958).Google Scholar
(6)Knopoff, L. and Gilbert, F.J. Acoust. Soc. Amer. 31 (1959), 11611168, 1169–1175.CrossRefGoogle Scholar
(7)Hobson, E. W.The theory of spherical and ellipsoidal harmonics, 2nd edn. (Chelsea Pub. Co., New York, 1955).Google Scholar
(8)Pflumm, E. Report BR 35. Division of Electromagnetic Research, New York University (1961). [See also Goodrich, R. F. and Kazarinoff, N. D.Proc. Cambridge Philos. Soc. 59 (1963), 167183.]CrossRefGoogle Scholar
(9)Copson, E. T.Asymptotic expansions (Cambridge University Press, 1965).CrossRefGoogle Scholar
(10)Erdélyi, A. et al. (editors). Higher transcendental functions, vols. 1 and 2 (McGraw-Hill; New York, 1953).Google Scholar
(11)Keller, J. B.Proc. 8th Symp. Appl. Math. Amer. Math. Soc. (McGraw-Hill; New York, 1958), 2752.Google Scholar
(12)Truesdell, C. and Toupin, R. A.The classical field theories. Handbuch der Physik (ed. Fl¨gge, S.), Band III/I, 226793 (Springer-Verlag; Berlin, 1960).Google Scholar
(13)Lighthill, M. J.Quart. J. Mech. Appl. Math. 3 (1950), 303325.CrossRefGoogle Scholar
(14)Olver, F. W. J.Philos. Trans. Boy. Soc. London Ser. A 247 (1955), 328368.Google Scholar
(15)Ragab, F. M.Comm. Pure Appl. Math. 11 (1958), 115127.CrossRefGoogle Scholar
(16)Chadwick, P. and Tupholme, G. E.Proc. Edinburgh Math. Soc. Forthcoming.Google Scholar
(17)Nussenzveig, H. M.Ann. Physics 34 (1965), 2395.CrossRefGoogle Scholar