A time domain three-dimensional sono-elastic method for ships’ vibration and acoustic radiation analysis in water
The classic three-dimensional hydroelasticity of ships is extend to include the effect of fluid compressibility, which yields the three-dimensional sono-elasticity of ships. To enable the predictions of coupled transient or nonlinear vibrations and acoustic radiations of ship structures, a time domain three-dimensional sono-elastic analysis method of acoustic responses of a floating structure is presented in this paper. The frequency domain added mass and radiation damping coefficients of the ship are first calculated by a three-dimensional frequency domain analysis method, from which a retardation function is derived and converted into the generalized time domain radiation force through a convolution integral. On this basis the generalized time domain sono-elastic equations of motion of the ship hull in water are established for calculation of the steady-state or transient-state excitation induced coupled vibrations and acoustic radiations of the ship. The generalized hydrodynamic coefficients, structural vibrations and underwater acoustic radiations of an elastic spherical shell excited by a concentrated pulsating force are illustrated and compared with analytical solutions with good agreement. The numerical results of a rectangular floating body are also presented to discuss the numerical error resultant from truncation of the upper integration limit in the Fourier integral of the frequency domain added mass coefficients for the retardation function.
KeywordsHydroelasticity sono-elasticity time domain Fourier transform vibration acoustic radiation
Unable to display preview. Download preview PDF.
- Wu Y. S. Hydroelasticity of floating bodies [D]. Doctoral Thesis, London, UK: Brunel University, 1984.Google Scholar
- Wu Y. S., Maeda H., Kinoshita T. The second order hydrodynamic actions on a flexible body [J]. SEISAN-KENKYU, Institute of Industrial Science of University of Tokyo, 1997, 49(4): 8–19.Google Scholar
- Hu J. J., Wu Y. S., Tian C., Wang X. L., Zhang F. Hydroelastic analysis and model test of structural responses and fatigue behaviors of an ultra large ore carrier in waves [J]. J. of Eng. for the Maritime Environment, 2012, 226(2): 135–155.Google Scholar
- Zou M. S. Three-dimensional sono-elasticity of ships [D]. Doctoral Thesis, Wuxi, China: China Ship Scientific Research Center, 2014(in Chinese).Google Scholar
- Zou M. S., Liu Y. M., Qi L. B. Structural-acoustic radiation of elastic thin spherical double-shell with contained water [J]. Journal of Ship Mechanics, 2013, 17(1–2): 155–163(in Chinese).Google Scholar
- Junger M. C., Feit D. Sound, structures, and their interaction, second edition [M]. Cambridge, Massachusetts, USA: The MIT Press, 1986, 280–287.Google Scholar