A 3D Higher Order Time Domain Rankine Panel Method for Wave-Current Interaction

2016 ◽  
Author(s):  
Felipe Ruggeri ◽  
Rafael A. Watai ◽  
Alexandre N. Simos
Keyword(s):  
Time Domain ◽  
Higher Order ◽  
Second Order ◽  
Panel Method ◽  
Order Effects ◽  
Rankine Panel Method ◽  
Wave Drift Damping ◽  
Current Interaction ◽  
Order Quantities ◽  
The University

The wave-current effects are very important in several offshore applications, for instance, the wave-drift-damping of a Turret moored FPSO. This papers presents the incorporation of current effects in the higher order time domain Rankine Panel Method on development in the Numerical Offshore Tank (TPN) at the University of São Paulo (USP) already introduced in [1]. The method is based on a perturbation theory to study first and second order effects, considering the geometry described using NURBS (Non Uniform Rational Basis Spline) and the potential function, free surface elevation, pressure etc by B-splines of arbitrary degree. The study is performed for a simplified geometry (sphere) and the results regarding a fixed hemisphere compared to other numerical methods considering both first and second order quantities are presented.

Ship Seakeeping Through the t = 1/4 Critical Frequency

1998 ◽  
Vol 42 (02) ◽  
pp. 113-119
Author(s):  
D. C. Kring
Keyword(s):  
Numerical Analysis ◽  
Time Domain ◽  
Critical Frequency ◽  
Three Dimensional ◽  
Panel Method ◽  
Gravitational Acceleration ◽  
Forward Speed ◽  
Rankine Panel Method ◽  
Physical Experiments

This study demonstrates that a bounded, physically relevant solution does exist at the so-called T = Uω/g = 1/4 resonance in the linear seakeeping problem for a realistic ship with forward speed, U, frequency of encounter, ω, and gravitational acceleration, g. The solution of the seakeeping problem by a linear, three dimensional, time-domain Rankine panel method, validated through numerical analysis, testing, and comparison to physical experiments, supports this claim. The solution can also be obtained with equal validity through frequencies both above and below the critical frequency.

Influence of the Higher-order Effects on the Second-order Breathers

2017 ◽  
Vol 23 (4) ◽  
pp. 365-371
Author(s):  
郝龙龙 HAO Long-long ◽  
宋丽军 SONG Li-jun
Keyword(s):  
Higher Order ◽  
Second Order ◽  
Order Effects ◽  
Higher Order Effects

First and Second Order Wave-Current Interactions for Floating Bodies

2012 ◽  
Author(s):  
Charles Monroy ◽  
Yann Giorgiutti ◽  
Xiao-Bo Chen
Keyword(s):  
Field Method ◽  
Boundary Integral ◽  
Second Order ◽  
Boundary Integral Method ◽  
Diffraction Radiation ◽  
Floating Bodies ◽  
Order Problem ◽  
First Order ◽  
Wave Drift Damping ◽  
Order Quantities

The influence of current in sea-keeping problems is felt not only for first order quantities such as wave run-ups in front of the structure, but also mainly for second order quantities. In particular, the wave drift damping (which is expressed as the derivative of drift force with respect to the current) is of special interest for mooring systems. The interaction effects of a double-body steady flow on wave diffraction-radiation is studied through a decomposition of the time-harmonic potential into linear and interaction components. A boundary integral method is used to solve the first order problem. Ultimately, a far-field method is proposed to get access to second order drift forces.

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