Regular and irregular wave impacts on floating body

Li, Yong; Lin, Mian

doi:10.1016/j.oceaneng.2012.01.019

Cited by 37 publications

(9 citation statements)

References 19 publications

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“…However, this method is based on the linear wave theory, hence will be limited within small wave steepness conditions. The computational fluid dynamic (CFD) method, which solves fully nonlinear Navier-Stokes equations covering the effect of viscous and turbulence, has been frequently used for hydrodynamic performance prediction in wave and floating body interaction process, and shows great potential in nonlinear effect prediction [21,22]. Wei et al studied the viscous effect and slamming process on bottom hinged oscillating wave energy converters based on the CFD software ANSYS Fluent, and revealed that CFD results agree well with experiments in capturing local features of the flow as well as dynamics of the device [23,24].…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Study of the Solo Duck Wave Energy Converter

Yao

Sun

et al. 2019

Energies

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The Edinburgh Duck is one of the highly-efficient wave energy converters (WECs). Compared to the spine-connected Duck configuration, the solo Duck will be able to use the point absorber effect to enhance its power capture performance. In this paper, a 3D computational fluid dynamic (CFD) model is developed to predict the hydrodynamic performance of the solo Duck WEC in regular waveswithin a wide range ofwave steepness until the Duck capsizes. A set of experiments was designed to validate the accuracy of the CFD model. Boundary element method (BEM) simulations are also performed for comparison. CFD results agree well with experimental results and the main difference comes from the friction in the mechanical transmission system. CFD results also agree well with BEM results and differences appear at large wave steepness as a result of two hydrodynamic nonlinear factors: the nonlinear waveform and the vortex generation process. The influence of both two nonlinear factors iscombined to be quantitatively represented by the drag torque coefficient.The vortex generation process is found to cause a rapid drop of the pressure force due to the vortexes taking away the kinetic energy from the fluid.

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Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Study of the Solo Duck Wave Energy Converter

Yao

Sun

et al. 2019

Energies

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“…In such cases, the potential flow theory is not valid and other tools based on Computational Fluid Dynamics (CFD) solvers to resolve the full Navier-Stokes equations or Lattice Boltzmann method (LBM) have been used [35][36][37][38][39][40]. Most of these problems have been formulated in 2D, and despite the increase of computational power, the full 3D models require a considerable computational cost.…”

Section: Introductionmentioning

confidence: 99%

A 3d Isogeometrical Boundary Element Analysis for Non-Linear Gravity Wave Propagation

Maestre¹,

Pallarès²,

Cuesta³

2016

Proceedings of the VII European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS Congress 2016)

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Abstract. In this paper we describe a three-dimensional Isogeometric BEM in the time domain based on the T-spline and Non Uniform Rational B-Splines (NURBS) basis to study the free surface behavior. Traditionally, the Lagrange polynomials have been used to discretize the geometry and the BEMs variables. The Lagrange basis are discontinues across the elements although the physical variables are continuous. In dynamics problems with high mesh distortions this approach can produce numerical instabilities that can be quickly propagated. This problem could be overcome using T-spline or NURB basis. The main advantages of this approach are: (1) the control of the continuity and smoothness of the T-spline and NURBS basis, which makes the model numerically stable without the need of artificial smooth techniques;(2) the high order geometrical approximation by non-rational splines;(3) the refinement capabilities without affecting the geometry and BEM's variables; and (4) the direct integration with computer aid geometrical design tools. We use the concept of the Bézier extraction operation which provides an element point of view of the T-Spline and NURBS similar to the traditional finite element. The boundary integral Equation is solved at each time step by the GMRES algorithm and the time marching scheme is performed with a fourth-order Runge-Kutta method to update the model. Additionally, the hydrodynamic force is calculated by an auxiliary boundary equation. Some numerical benchmark examples are analysed to show the accuracy and the stability of the method 7967 J. Maestre, J. Pallarés and I. Cuesta

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“…The different modes of body motion were more specifically studied in a recent paper by Zhou et al (2013). For completeness, numerical models based on the full Navier-Stokes equations were also proposed in 2D (Rahman et al (2006);Hadžić et al (2005); Ghasemi et al (2014)) and, in particular, wave impact on structures in regular and irregular waves was also investigated in Li and Lin (2012). But the accurate direct solution of Navier-Stokes equations for non-linear wave-structure interaction problems, particularly in 3D, still remains a computationally formidable task that poses greater numerical difficulties than when using potential flow theory.…”

Section: Introductionmentioning

confidence: 99%

Simulation of floating structure dynamics in waves by implicit coupling of a fully non-linear potential flow model and a rigid body motion approach

Dombre

Benoît

Violeau

et al. 2014

J. Ocean Eng. Mar. Energy

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We demonstrate the accuracy and convergence of a new numerical model solving wave-structure interactions based on the fully non-linear potential flow (FNPF) theory coupled to a rigid body motion approach. This work extends an earlier model proposed by Guerber et al. (Eng Anal Bound Elements 36(7):1151-1163, 2012), restricted to fully submerged structures, by allowing to solve for freely floating bodies on the free surface. Although we are currently extending the model to three dimensions (3D), the work reported here only considers two-dimensional (2D) problems. We first introduce the FNPF model, We then detail the numerical scheme used for coupling the FNPF model to the motion of a floating rigid body. Moreover, we propose a new numerical strategy for advancing the free surface front inspired by symplectic integrators, which achieves a much better performance for energy conservation. The developed algorithm is first applied to forced motion cases, for which analytical and experimental results can be found in the literature and used as benchmarks. The accuracy of the numerical solution for the fluid and applied forces is then discussed for cases with small or large amplitude motion. In the latter case, a preliminary investigation of non-linear effects is performed for the classical application of a semi-circular heaving cylinder, by comparing the computed hydrodynamic force to the experimental measurements of Yamashita (J Soc Nav Arch 141: [61][62][63][64][65][66][67][68][69][70] 1977). In particular, the comparison of the magnitude of the force harmonics, up to the third order, shows the importance of simulating non-linear interactions, which become important as the ratio of the radius of the cylinder over the wavelength increases. In a second set of applications, we assess the model accuracy in dealing with freely floating bodies. As a first test case, we consider the decaying motion of a freely heaving horizontal circular cylinder released from a non-equilibrium position above the free surface. In this more demanding computations, we verify that total energy fluid-plus-body motion is well conserved, which confirms the accuracy of the fluid-structure interaction algorithm. As a second test case, we consider the free motion of a rectangular barge in waves and compute the first-order response amplitude operators.

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Regular and irregular wave impacts on floating body

Cited by 37 publications

References 19 publications

Numerical and Experimental Study of the Solo Duck Wave Energy Converter

Numerical and Experimental Study of the Solo Duck Wave Energy Converter

A 3d Isogeometrical Boundary Element Analysis for Non-Linear Gravity Wave Propagation

Simulation of floating structure dynamics in waves by implicit coupling of a fully non-linear potential flow model and a rigid body motion approach

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