Fully-Nonlinear Simulation of the Hydrodynamics of a Floating Body in Surface Waves by a High-Order Boundary Element Method

2015 ◽  
Author(s):  
Chengxi Li ◽  
Yuming Liu
Keyword(s):  
Boundary Element Method ◽  
Rigid Body ◽  
Surface Waves ◽  
Boundary Element ◽  
Nonlinear Wave ◽  
Empirical Modeling ◽  
Body Motion ◽  
Viscous Effect ◽  
Fully Nonlinear ◽  
Element Method

The objective of this work is to understand and evaluate the hydrodynamics modeling of a floating rigid body in regular and irregular ocean surface waves. Direct time-domain numerical simulation, based on the potential-flow formulation with the use of a quadratic boundary element method, is employed to compute the response of the body under the action of surface waves including fully-nonlinear wave-body interaction effects associated with steep waves and large-amplitude body motions. The viscous effect due to flow separation and turbulence is included by empirical modeling. The simulation results of body motions are compared with laboratory experimental measurements. The nonlinear effects due to body motion and wave motion are quantified and compared to the viscous effect. Their relative importance in the prediction and modeling of a rigid body motion under various wave conditions is investigated. This study may provide essential information pertaining to develop effective modeling of nonlinear wave-body interactions which is needed in design of offshore structures and wave energy conversion devices.

Vibrations of Foundations Interacting With Subsoil Experimental Studies and BE Calculations

1991 ◽  
Author(s):  
L. Gaul
Keyword(s):  
Boundary Element Method ◽  
Dynamic Response ◽  
Surface Waves ◽  
Boundary Element ◽  
Constitutive Equations ◽  
Experimental Studies ◽  
Boundary Elements ◽  
Experimental Techniques ◽  
Embedded Structures ◽  
Element Method

Abstract Calculation of the dynamic response of sensitive structures like foundations for vibrating machinery requires to take the interaction with subsoil into account. Structures and soil are discretized by boundary elements and coupled by a substructure technique. Viscoelastic constitutive equations contain fractional time derivatives. Surface waves generated by machine foundations and diffracted by embedded structures and soil inhomogeneities are analyzed by conventional and optoelectronic experimental techniques and calculated by the boundary element method (BEM).

Removing Non-Uniqueness in Symmetric Galerkin Boundary Element Method for Elastostatic Neumann Problems and its Application to Half-Space Problems

2020 ◽  
Vol 36 (6) ◽  
pp. 749-761
Author(s):  
Y. -Y. Ko
Keyword(s):  
Boundary Element Method ◽  
Rigid Body ◽  
Boundary Element ◽  
Integral Equations ◽  
Half Space ◽  
Boundary Integral Equations ◽  
Boundary Integral ◽  
Neumann Problems ◽  
Galerkin Boundary Element Method ◽  
Element Method

ABSTRACTWhen the Symmetric Galerkin boundary element method (SGBEM) based on full-space elastostatic fundamental solutions is used to solve Neumann problems, the displacement solution cannot be uniquely determined because of the inevitable rigid-body-motion terms involved. Several methods that have been used to remove the non-uniqueness, including additional point support, eigen decomposition, regularization of a singular system and modified boundary integral equations, were introduced to amend SGBEM, and were verified to eliminate the rigid body motions in the solutions of full-space exterior Neumann problems. Because half-space problems are common in geotechnical engineering practice and they are usually Neumann problems, typical half-space problems were also analyzed using the amended SGBEM with a truncated free surface mesh. However, various levels of errors showed for all the methods of removing non-uniqueness investigated. Among them, the modified boundary integral equations based on the Fredholm’s theory is relatively preferable for its accurate results inside and near the loaded area, especially where the deformation varies significantly.

Numerical Simulations of Large Deep Water Waves: The Application of a Boundary Element Method

2006 ◽  
Author(s):  
Caroline H. Hague ◽  
Chris Swan
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Deep Water ◽  
Water Waves ◽  
Physical Space ◽  
Wave Model ◽  
Three Dimensions ◽  
Fully Nonlinear ◽  
Highly Nonlinear ◽  
Element Method

This paper concerns the description of extreme surface water waves in deep water. A fully nonlinear numerical wave model in three dimensions is presented, based on the Boundary Element Method (BEM), and is applied to nonlinear focusing of wave components with varying frequency and direction of propagation to form highly nonlinear groups. By using multiple fluxes at corners and edges of the numerical domain the “corner problem” associated with BEM-based models in physical space is overcome. A two-dimensional version of the method is also employed to model unidirectional cases, and examples presented include the focusing of Top Hat spectra in deep water to form highly nonlinear wave groups at or close to their breaking limit. The ability of the model to accurately simulate these sea states is highlighted by comparison to the fully nonlinear model of Bateman, Swan and Taylor (2001, 2003).

A sparse boundary‐element method for scattering from a rigid body of revolution

1993 ◽  
Vol 94 (3) ◽  
pp. 1783-1784
Author(s):  
Erik M. Rosen ◽  
Luise S. Couchman ◽  
Francis X. Canning
Keyword(s):  
Boundary Element Method ◽  
Rigid Body ◽  
Boundary Element ◽  
Body Of Revolution ◽  
Element Method
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