Unsteady three-dimensional sources in deep water with an elastic cover and their applications
Abstract The velocity potential is derived for a transient source of arbitrary strength undergoing arbitrary three-dimensional motion. The initially quiescent fluid of infinite depth is assumed to be inviscid, incompressible and homogeneous. The upper surface of the fluid is covered by a thin layer...
Published in: | Journal of Fluid Mechanics |
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Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
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Cambridge University Press (CUP)
2013
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Online Access: | http://dx.doi.org/10.1017/jfm.2013.303 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112013003030 |
Summary: | Abstract The velocity potential is derived for a transient source of arbitrary strength undergoing arbitrary three-dimensional motion. The initially quiescent fluid of infinite depth is assumed to be inviscid, incompressible and homogeneous. The upper surface of the fluid is covered by a thin layer of elastic material of uniform density with lateral stress. The linearized initial boundary-value problem is formulated within the framework of the potential-flow theory, and the Laplace transform technique is employed to obtain the solution. The potential of a time-harmonic source with forward speed is obtained as a particular case. The far-field wave motion at long time is determined via the method of stationary phase. The problems of radiation (surge, sway and heave) of the flexural–gravity waves by a submerged sphere advancing at constant forward speed are investigated. The method of multipole expansions is used. Numerical results are obtained for the wave-making resistance and lift, added-mass and damping coefficients. The effects of an ice sheet and broken ice on the hydrodynamic loads are discussed in detail. |
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