Exact evaluation of hydrodynamic loads on ships using NURBS surfaces and acceleration potential

Abbasnia, Arash; Soares, C. Guedes

doi:10.1016/j.enganabound.2017.09.005

Cited by 11 publications

(9 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similarly X G , Y G , Z G in relation to their values at the initial instant represent the usual surge, sway, and heave motions. The (1) [M] displacements of the body in the earth system can thus be determined by first integrating Eq. (1) to get �� ⃗ U, �� ⃗ and then Eq.…”

Section: The Hydrodynamic Problem and Its Numerical Solutionmentioning

confidence: 99%

“…In Eqs. (12a, 12b), (1) and (2) are the total first-and second-order potential, ⃗ X is linear displacement at a point on S B (0) , ⃗ X G and ⃗ G are the translational and rotational acceleration of the body at C.G., R is the transformation matrix, and r is the relative vertical displacement at waterline wl . The terms r , ⃗ X , ⃗ X G , ⃗ G , and R in the above are all derived from the firstorder (linear) solution.…”

Section: Determination Of the Forces/momentsmentioning

confidence: 99%

“…For realistic geometries, this number can be large, e.g., in the twin-barge problem of Feng and Bai [12], the total number of mesh/elements used is nearly 7000. Such large matrix size poses a considerable strain on the computational time, limiting the simulation run to only a few periods (see, e.g., [1]). Some of the researches in this context have focused on the development and application of higher order spline-based boundary element methods (BEMs) with the aim of reducing the total number of meshes for the same level of accuracy achievable from a low-order BEM.…”

Section: Introductionmentioning

confidence: 99%

“…Some of the researches in this context have focused on the development and application of higher order spline-based boundary element methods (BEMs) with the aim of reducing the total number of meshes for the same level of accuracy achievable from a low-order BEM. These higher order BEMs are also being explored for their ability to better resolve some of the required interior parameters such as the spatial derivatives and body-free-surface intersection lines [1,2,5] compared to a low-order BEM. Alternative forms of BEM such as application of desingularized methods which enable a reduction in the total number of panels without sacrificing accuracy are also being explored [13].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Prediction of non-linear wave loads on large floating structures using a 3D numerical wave tank approach

Ganesan

Sen

2019

Mar Syst Ocean Technol

View full text Add to dashboard Cite

In the present work, non-linear wave loads acting on large floating structures are computed using a 3D numerical wave tank (NWT) approach in an approximate manner. The hydrodynamic initial boundary value problem is solved following a Rankine panel-based boundary element method in conjunction with time integration of free-surface constraints and bodymotion equations. To enable long-duration simulation for practical offshore configurations, total velocity potential is split into incident and perturbation part, and the latter effects are linearized. In our earlier works (Ganesan and Sen in J Ocean Eng Mar Energy 1:299-324, 2015; Ganesan and Sen in Appl Ocean Res 51:153-170, 2015), the 2nd order contributions from the linearized perturbation potential were neglected. In this work, we propose a modified formulation for the external load in which the full non-linear loads from the incident wave and up to 2nd order loads from the linear perturbation potential are considered. After presenting some results to validate the present method for steady drift force computations, non-linear loads from the modified formulation are compared with the unmodified form of the method and also with widely used 3D frequency-domain Green-function-based method. Comparative results between these three computations are presented for different geometries and the results are discussed to bring out the relative advantage of the modified formulation in predicting non-linear loads across the range of frequency and wave steepness. Keywords 3D numerical wave tank • Rankine panel method • Direct time domain • Higher order forces • Non-linear wave • Mean drift forces * Shivaji Ganesan T.

show abstract

Section: The Hydrodynamic Problem and Its Numerical Solutionmentioning

confidence: 99%

Section: Determination Of the Forces/momentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Prediction of non-linear wave loads on large floating structures using a 3D numerical wave tank approach

Ganesan

Sen

2019

Mar Syst Ocean Technol

View full text Add to dashboard Cite

show abstract

“…ey used the disturbed potential method proposed by Ferrant et al [6]. Abbasnia and Soares [27] also examined the motion of the Wigley hull using the PNWT technique with the 3D NURBS method. In addition, the PNWT technique was used for wave resistance and wave pattern analysis for a ship with a forward speed [28,29].…”

Section: Introductionmentioning

confidence: 99%

Development of a Three‐Dimensional Fully Nonlinear Potential Numerical Wave Tank for a Heaving Buoy Wave Energy Converter

Kim

Koo

2019

Mathematical Problems in Engineering

View full text Add to dashboard Cite

The hydrodynamic performance of a vertical cylindrical heaving buoy-type floating wave energy converter under large-amplitude wave conditions was calculated. For this study, a three-dimensional fully nonlinear potential-flow numerical wave tank (3D-FN-PNWT) was developed. The 3D-FN-PNWT was based on the boundary element method with Rankine panels. Using the mixed Eulerian–Lagrangian (MEL) method for water particle movement, nonlinear waves were produced in the PNWT. The PNWT can calculate the wave forces acting on the buoy accurately using an acceleration potential approach. The constant panels and least-square gradient reconstruction method were applied to regridding of computational boundaries. An artificial damping zone was employed to satisfy the open-sea conditions at the end free surface boundaries. The diffraction and radiation problems were solved, and their solutions were confirmed by a comparison with previous studies. The interaction of the incident wave, floating body, and power take-off (PTO) behavior was examined in the time domain using the developed 3D-FN-PNWT. From comparison, the difference between the conventional linear analysis and the nonlinear analysis in large-amplitude waves was examined.

show abstract

Transient fully nonlinear ship waves using a three-dimensional NURBS numerical towing tank

Abbasnia

Soares²

2018

Engineering Analysis with Boundary Elements

View full text Add to dashboard Cite

Exact evaluation of hydrodynamic loads on ships using NURBS surfaces and acceleration potential

Cited by 11 publications

References 17 publications

Prediction of non-linear wave loads on large floating structures using a 3D numerical wave tank approach

Prediction of non-linear wave loads on large floating structures using a 3D numerical wave tank approach

Development of a Three‐Dimensional Fully Nonlinear Potential Numerical Wave Tank for a Heaving Buoy Wave Energy Converter

Transient fully nonlinear ship waves using a three-dimensional NURBS numerical towing tank

Contact Info

Product

Resources

About