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Acoustic approximation in the slamming problem

Published online by Cambridge University Press:  26 April 2006

Alexander Korobkin
Affiliation:
Norwegian Institute of Technology, Trondheim, Norway Permanent address: Lavrentyev Institute of Hydrodynamics, Novosibirsk, 630090, Russia.

Abstract

The plane unsteady problem of the deflection of a solid, slightly curved plate in collision with an ideal weakly compressible liquid is considered. In order to describe the impact process, the acoustic approximation and the method of normal modes are used. The analysis is focused on the supersonic stage of the impact when the liquid surface remains undisturbed outside the contact spot between the solid plate and the liquid. However, the positions of the contact points are unknown in advance, in contrast to the case of undeformable body impact, and have to be found together with the liquid flow, the pressure distribution, and the bottom deformations. It was shown that the duration of the supersonic stage depends on the entering body elasticity. A spray jet is formed earlier and the stage at which the liquid compressibility is a governing factor is shorter than under rigid-body impact. It is revealed that the elastic plate deflection is quite small and can be satisfactorily approximated by a few modes. On the other hand, the calculation of the bending stress distribution needs a much greater number of normal modes. The pressure distribution over the contact region is quite difficult to find by the mode method; an alternative approach is suggested.

Type
Research Article
Copyright
© 1996 Cambridge University Press

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References

Bowden, F. P. & Field, J. E. 1964 The brittle fracture of solids by liquid impact, by solid impact, and by shock. Proc. R. Soc. Lond. A 282, 331352.Google Scholar
Korobkin, A. A. 1985 Initial asymptotics in the problem of blunt body entrance into liquid. PhD thesis, Lavrentyev Institute of Hydrodynamics.
Korobkin, A. A. 1992a Acoustic approximation in the problem of penetration of a blunt contour into ideal fluid. Zh. Prikl. Mekh. Tekh. Fiz. 4, 4854.Google Scholar
Korobkin, A. A. 1992b Blunt-body impact on a compressible liquid surface. J. Fluid Mech. 244, 437453.Google Scholar
Korobkin, A. A. 1994 Low-pressure zones under a liquid-solid impact. In IUTAM Symposium on Bubble Dynamics and Interface Phenomena (ed. J. R. Blake & N. H. Thomas), pp. 375381. Kluwer.
Korobkin, A. A. 1996 Global characteristics of jet impact. J. Fluid Mech. 307, 6384.Google Scholar
Korobkin, A. A. & Pukhnachov, V. V. 1985 Initial asymptotics in contact hydrodynamics problems. In 4th Intl Conf. Numer. Ship Hydrodyn. (ed. J. H. McCarthy), pp. 138151. Bethesda, MD: David W. Taylor Naval Ship Res. Dev. Center.
Krasilshchikova, E. A. 1982 A Thin Wing in a Compressible Flow. Moscow: Mir; Plenum.
Kvålsvold, J. & Faltinsen, O. M. 1993a Hydroelastic modelling of slamming against the wetdeck of a catamaran. In 8th Workshop on Water Waves and Floating Bodies.
Kvålsvold, J. & Faltinsen, O. M. 1993b Hydroelastic modelling of slamming against the wetdeck of a catamaran. In FAST’93.
Kvålsvold, J. & Faltinsen, O. M. 1994 Hydroelastic study of wetdeck slamming by a Timoshenko beam model. In Intl Conf. Hydroelasticity in Marine Technology (ed. O. M. Faltinsen). Trondheim: The Norwegian Institute of Technology.
Lesser, M. B. 1981 Analytic solutions of liquid-drop impact problems. Proc. R. Soc. Lond. A 377, 289308.Google Scholar
Sharov, Ya. F. 1958 Ship bottom impact upon wave. Sudostroyeniye 4, 59.Google Scholar
Zhu, L. & Faulkner, D. 1994 Slamming drop tests for small scale SWATH characteristic model. Tech. Rep. NAOE-94-34. Department of Naval Architecture and Ocean Engineering. University of Glasgow, Glasgow.