Numerical Simulations of Wave-Induced Ship Motions in Time Domain by a Rankine Panel Method

2010 ◽  
Vol 22 (3) ◽  
pp. 373-380 ◽  
Author(s):  
Jing-pu Chen ◽  
De-xiang Zhu
Keyword(s):  
Numerical Simulations ◽  
Time Domain ◽  
Panel Method ◽  
Ship Motions ◽  
Rankine Panel Method ◽  
Wave Induced

Numerical simulations of wave-induced ship motions in regular oblique waves by a time domain panel method

2010 ◽  
Vol 22 (S1) ◽  
pp. 408-415 ◽  
Author(s):  
Jing-pu Chen ◽  
De-xiang Zhu
Keyword(s):  
Numerical Simulations ◽  
Time Domain ◽  
Panel Method ◽  
Ship Motions ◽  
Oblique Waves ◽  
Wave Induced

Improvement of Rankine Panel Method for Seakeeping Prediction of a Ship in Low Frequency Region

2016 ◽  
Author(s):  
Eiji Yasuda ◽  
Hidetsugu Iwashita ◽  
Masashi Kashiwagi
Keyword(s):  
Low Frequency ◽  
Radiation Condition ◽  
Panel Method ◽  
Ship Motions ◽  
Surface Boundary ◽  
Low Frequencies ◽  
Computational Region ◽  
Rankine Panel Method ◽  
Free Surface Boundary Condition ◽  
Wave Induced

Rankine panel methods have been studied for solving 3D seakeeping problems of a ship with forward speed and oscillatory motions. Nevertheless, there is a drawback in the numerical method for satisfying the radiation condition of outgoing waves at low frequencies, because the waves generated ahead of a ship reflect from the outward computational boundary and smear the flow around the ship. The so-called panel shift technique has been adopted in the frequency-domain Rankine panel method, which is effective when the generated waves propagate downstream of a ship. In this paper, in addition to this conventional panel shift method, Rayleigh’s artificial friction is introduced in the free-surface boundary condition to suppress longer wave components in a computational region apart from the ship. With this practical new method, it is shown that there is no prominent wave reflection from the side and/or upstream computational boundaries even in the range of low frequencies. As a consequence, the unsteady pressure, hydrodynamic forces, wave-induced ship motions, added resistance are computed with reasonable accuracy even in following waves and in good agreement with measured results in the experiment using a bulk carrier model which is also conducted for the present study.

A new time domain Rankine panel method for simulations involving multiple bodies with large relative displacements

2016 ◽  
Vol 59 ◽  
pp. 93-114 ◽  
Author(s):  
R.A. Watai ◽  
F. Ruggeri ◽  
A.N. Simos
Keyword(s):  
Time Domain ◽  
Panel Method ◽  
Rankine Panel Method ◽  
New Time

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.

scholarly journals Numerical Analysis of Added Resistance on Ships by a Time-domain Rankine Panel Method

2010 ◽  
Vol 47 (3) ◽  
pp. 398-409 ◽  
Author(s):  
Kyong-Hwan Kim ◽  
Yong-Hwan Kim
Keyword(s):  
Numerical Analysis ◽  
Time Domain ◽  
Panel Method ◽  
Added Resistance ◽  
Rankine Panel Method

Motion Prediction of the Ship With Sloshing Tanks

2009 ◽  
Author(s):  
Kang Zou ◽  
Quan-ming Miao ◽  
Ren-qing Zhu
Keyword(s):  
Time Domain ◽  
Three Dimensional ◽  
Panel Method ◽  
Ship Motion ◽  
Motion Prediction ◽  
Ship Motions ◽  
Motion Responses ◽  
Motion Problem ◽  
Good Agreement

Sloshing flow in ship tanks is excited by ship motions, but it affects the ship motions in reverse. This paper focuses on the motion responses of the ship in waves with consideration of coupled effects with sloshing in tanks. A three-dimensional panel method in time-domain is applied to solve the ship motion problem, and the sloshing tanks are solved by commercial CFD software simultaneously. Experiments were carried out on a SL175 ship and good agreement is obtained.

A Rankine Panel Method for Added Resistance of Ships in Waves

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Heinrich Söding ◽  
Vladimir Shigunov ◽  
Thomas E. Schellin ◽  
Ould el Moctar
Keyword(s):  
Degrees Of Freedom ◽  
Periodic Wave ◽  
Panel Method ◽  
Navier Stokes ◽  
Ship Motions ◽  
Added Resistance ◽  
Rankine Panel Method ◽  
Head Waves ◽  
Wigley Hull ◽  
The Time Domain

A new Rankine panel method and an extended Reynolds-Averaged Navier–Stokes (RANS) solver were employed to predict added resistance in head waves at different Froude numbers of a Wigley hull, a large tanker, and a modern containership. The frequency domain panel method, using Rankine sources as basic flow potentials, accounts for the interaction of the linear periodic wave-induced flow with the nonlinear steady flow caused by the ship's forward speed in calm water, including nonlinear free surface conditions and dynamic squat. Added resistance in waves is obtained by the pressure integration method. The time domain RANS solver, based on a finite volume method, is extended to solve the nonlinear equations of the rigid body six-degrees-of-freedom ship motions. The favorable comparison of the panel and RANS predictions demonstrated that the Rankine method is suitable to efficiently obtain reliable predictions of added resistance of ships in waves. Comparable model test predictions correlated less favorably, although the overall agreement was felt to be acceptable, considering the difficulties associated with the procedures to obtain accurate measurements.

An Investigation Into the Limitations of the Panel Method and the Gap Effect for a Fixed and a Floating Structure Subject to Waves

2016 ◽  
Author(s):  
Blanca Peña ◽  
Aaron McDougall
Keyword(s):  
Time Domain ◽  
Real Life ◽  
Added Mass ◽  
Panel Method ◽  
Gap Effect ◽  
Wave Radiation ◽  
Literature Study ◽  
Floating Structure ◽  
Cfd Analyses ◽  
Wave Induced

The wave-induced motions of vessels moored next to a fixed object and open to the sea impact the operability of many offshore operations, and should be assessed in order to avoid accidents and catastrophes. When analysing vessels moored by a fixed object (e.g. quay-side or platform), time domain simulations have shown numeric instabilities resulting in unreliable outcomes. The origin of the numerical instability might lie in the hydrodynamic added mass and wave radiation damping. This is typically calculated using potential flow methods and influenced by the existence of standing waves in the gap between the two bodies. For certain frequencies, these give negative values, potentially causing instabilities in non-linear (coupled) time domain simulations. In these cases, the vessel can behave unexpectedly, generating energy rather than dissipating it. As such, certain simulations have been disregarded as they are unlikely to accurately represent real-life scenarios. This paper investigates and compares added mass and damping using two different tools and studies the gap effect when conducting diffraction analysis using 3D panel methods. The work covers a literature study into potential theory, multibody analysis, Computational Fluid Dynamics (CFD) and lid techniques. This is followed by a study conducted using both panel method and CFD analyses. The results from both approaches have been compared, showing interesting information and the necessity of researching more into the problem addressed in this paper.

Time Domain Simulation of the Maneuvering of a Vessel in a Seaway

2009 ◽  
Author(s):  
Elin Marita Hermundstad ◽  
Jan R. Hoff
Keyword(s):  
Time Domain ◽  
Transfer Functions ◽  
Experimental Results ◽  
Numerical Code ◽  
Ship Motions ◽  
Time Domain Simulation ◽  
Regular Waves ◽  
Simulation Code ◽  
Wigley Hull ◽  
Wave Induced

This paper presents a new unified seakeeping-maneuvering simulation model valid for surface ships and underwater vessels. If the total ship motions are derived from the traditional formulations for the hydrodynamic and maneuvering models, considering them as two separate problems, the results will be inconsistent. It has therefore been necessary to develop a unified formulation which calculates the total ship motions including both the maneuvering aspects and the wave induced motions. Focus in this study has been on submarines. Examples of application of the developed time domain simulation code are given. These are simulations of the response and corresponding control plane forces of a submarine in straight line motions in regular waves at given headings. The developed code can also be used to e.g. simulate turning circles. This has been conducted for the same submarine, and the results are compared to experimental results. Additionally, simulations of the response of a surface vessel (Wigley hull) with forward speed in regular waves at given headings are presented. In this case only the potential forces are considered. The results from the simulations are used to establish motion transfer functions, which are compared to other numerical and experimental results. There are some limitations in the developed method which affects the application area of the numerical code. This refers particularly to underwater vessels. This will be addressed, and further possible development of the method will be discussed.

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