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Citation:
 Eduard Amromin.Ships Bottom Cavities as Shock Absorbers in Waves[J].Journal of Marine Science and Application,2018,(2):173-177.[doi:10.1007/s11804-018-0019-3]
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Ships Bottom Cavities as Shock Absorbers in Waves

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Title:
Ships Bottom Cavities as Shock Absorbers in Waves
Author(s):
Eduard Amromin
Affilations:
Author(s):
Eduard Amromin
Mechmath LLC, Federal Way, WA 98003, USA
Keywords:
Ship bottom cavitationWavy seasMitigation of force pulsationVertical acceleration
分类号:
-
DOI:
10.1007/s11804-018-0019-3
Abstract:
Bottom ventilated cavitation is the successfully proven ship drag reduction technology, but the impact of sea waves on ships with bottom cavities is the substantial concern for a broad technology implementation. The influence of waves on vertical force experienced by such ships is analyzed in this paper using a perturbation technique. The unperturbed cavity shape at given Froude number and cavity length was found from a nonlinear steady ideal fluid problem. The ship response to an impact of a wave of the given length and amplitude is considered as the one-frequency perturbation. This perturbation was found by combined consideration of compressible flow in the cavity and incompressible flow in the surrounding water. Computational examples relate to an earlier tested model with the bottom cavity restricted by skegs. The vertical forces on the model with bottom cavities and in cavitation-free conditions were compared in head and following seas. It was found that within the major part of the consider range of wavelengths the cavity acts as a shock absorber significantly reducing the vertical force pulsation and ship acceleration in waves.

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Memo

Memo:
Received date:2017-08-20;Accepted date:2017-10-05。
Corresponding author:Eduard Amromin,amromin@aol.com
Last Update: 2018-10-11