NUMERICAL AND EXPERIMENTAL STUDY OF THE PARAMETRIC ROLLING OF A FISHING VESSEL IN REGULAR HEAD WAVES

2021 ◽  
Vol 155 (A4) ◽  
Author(s):  
E Uzunoglu ◽  
S. Ribeiro E Silva ◽  
C. Guedes Soares ◽  
R. Zamora ◽  
L. Perez Rojas
Keyword(s):  
Degrees Of Freedom ◽  
Assessment Tool ◽  
Prediction Method ◽  
Theory Model ◽  
Design Stage ◽  
Ship Motions ◽  
Fishing Vessel ◽  
Parametric Rolling ◽  
Strip Theory ◽  
Head Waves

The dynamic behaviour of a fishing vessel in waves is studied in order to reveal its parametric rolling characteristics. This paper presents experimental and numerical results in longitudinal regular waves. The experimental results are compared against the results of a time-domain non-linear strip theory model of ship motions in six degrees-of-freedom. These results contribute to the validation of the parametric rolling prediction method, so that it can be used as an assessment tool to evaluate both the susceptibility and severity of occurrence of parametric rolling at the early design stage of these types of vessels.

Numerical and Experimental Study of the Parametric Rolling of a Fishing Vessel in Regular Head Waves

2013 ◽  
Vol 155 (A4) ◽  
Keyword(s):  
Degrees Of Freedom ◽  
Assessment Tool ◽  
Prediction Method ◽  
Theory Model ◽  
Design Stage ◽  
Ship Motions ◽  
Fishing Vessel ◽  
Parametric Rolling ◽  
Strip Theory ◽  
Head Waves

The dynamic behaviour of a fishing vessel in waves is studied in order to reveal its parametric rolling characteristics. This paper presents experimental and numerical results in longitudinal regular waves. The experimental results are compared against the results of a time-domain non-linear strip theory model of ship motions in six degrees-of-freedom. These results contribute to the validation of the parametric rolling prediction method, so that it can be used as an assessment tool to evaluate both the susceptibility and severity of occurrence of parametric rolling at the early design stage of these types of vessels.

Parametric Rolling Simulations of Container Ships

2013 ◽  
Author(s):  
Anton Turk ◽  
Jasna Prpić-Oršić ◽  
Carlos Guedes Soares
Keyword(s):  
Time Domain ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Full Range ◽  
Ship Motions ◽  
Computationally Efficient ◽  
Parametric Roll ◽  
Parametric Rolling ◽  
Strip Theory ◽  
The Time Domain

A hybrid nonlinear time domain seakeeping analysis is applied to the study of a container ship advancing at different headings and encounter frequencies. A time-domain nonlinear strip theory in six degrees-of-freedom has been extended to predict ship motions by solving the unsteady hydrodynamic problem in the frequency domain and the equations of motion in the time domain which allows introducing nonlinearities in the linear model. The code is used to make parametric roll predictions for various speeds and headings and the results are summarized in a very intuitive 2D and 3D polar plots showing the full range of the parametric rolling realizations. The method developed is fairly accurate, robust, very computationally efficient, and can predict nonlinear ship motions. It is well suited to be used as a tool in ship design or as part of a path optimization model.

Non-Linear Time Domain Simulation of Dynamic Instabilities in Longitudinal Waves

2008 ◽  
Author(s):  
S. Ribeiro e Silva ◽  
C. Guedes Soares
Keyword(s):  
Time Domain ◽  
Degrees Of Freedom ◽  
Linear Time ◽  
Simulation Method ◽  
Ship Motions ◽  
Computational Technique ◽  
Parametric Rolling ◽  
Longitudinal Waves ◽  
Six Degrees Of Freedom ◽  
Strip Theory

A time domain numerical simulation method is developed to determine ship motions in six degrees-of-freedom and to detect dynamic instabilities in both regular and irregular longitudinal waves. The basic approach of the simulation program involves computation of hydrodynamic coefficients of added mass and damping, restoring coefficients and diffraction and Froude-Krylov excitation forces at each step in time according to the instantaneous waterline and vessel position, using a strip theory method and a pressure integration technique along the segments. This paper briefly describes the computational technique utilized and makes comparisons between numerical and experimental roll damping data to infer about its influence on roll amplitude under parametric rolling conditions. An investigation into the dynamic stability in waves of a container vessel example.

NUMERICAL PREDICTION OF VERTICAL SHIP MOTIONS AND ADDED RESISTANCE

2021 ◽  
Vol 159 (A4) ◽  
Author(s):  
F Cakici ◽  
E Kahramanoglu ◽  
A D Alkan
Keyword(s):  
Deep Water ◽  
High Speed ◽  
Computer Experiments ◽  
Navier Stokes ◽  
Ship Motions ◽  
Added Resistance ◽  
Strip Theory ◽  
Head Waves ◽  
Computational Fluid Dynamics Cfd ◽  
Volume Method

Along with the development of computer technology, the capability of Computational Fluid Dynamics (CFD) to conduct ‘virtual computer experiments’ has increased. CFD tools have become the most important tools for researchers to deal with several complex problems. In this study, the viscous approach called URANS (Unsteady Reynolds Averaged Navier-Stokes) which has a fully non-linear base has been used to solve the vertical ship motions and added resistance problems in head waves. In the solution strategy, the FVM (Finite Volume Method) is used that enables numerical discretization. The ship model DTMB 5512 has been chosen for a series of computational studies at Fn=0.41 representing a high speed case. Firstly, by using CFD tools the TF (Transfer Function) graphs for the coupled heave- pitch motions in deep water have been generated and then comparisons have been made with IIHR (Iowa Institute of Hydraulic Research) experimental results and ordinary strip theory outputs. In the latter step, TF graphs of added resistance for deep water have been generated by using CFD and comparisons have been made only with strip theory.

Numerical Prediction of Vertical Ship Motions and Added Resistance

2017 ◽  
Vol 159 (A4) ◽  
Author(s):  
F Cakici ◽  
E Kahramanoglu ◽  
A D Alkan
Keyword(s):  
Deep Water ◽  
High Speed ◽  
Computer Experiments ◽  
Navier Stokes ◽  
Ship Motions ◽  
Added Resistance ◽  
Strip Theory ◽  
Head Waves ◽  
Computational Fluid Dynamics Cfd ◽  
Volume Method

Along with the development of computer technology, the capability of Computational Fluid Dynamics (CFD) to conduct ‘virtual computer experiments’ has increased. CFD tools have become the most important tools for researchers to deal with several complex problems. In this study, the viscous approach called URANS (Unsteady Reynolds Averaged Navier-Stokes) which has a fully non-linear base has been used to solve the vertical ship motions and added resistance problems in head waves. In the solution strategy, the FVM (Finite Volume Method) is used that enables numerical discretization. The ship model DTMB 5512 has been chosen for a series of computational studies at Fn=0.41 representing a high speed case. Firstly, by using CFD tools the TF (Transfer Function) graphs for the coupled heave-pitch motions in deep water have been generated and then comparisons have been made with IIHR (Iowa Institute of Hydraulic Research) experimental results and ordinary strip theory outputs. In the latter step, TF graphs of added resistance for deep water have been generated by using CFD and comparisons have been made only with strip theory.

Unsteady Viscous CFD Simulations of KCS Behaviour and Performance in Head Seas

2018 ◽  
Author(s):  
LiXiang Guo ◽  
JiaWei Yu ◽  
JiaJun Chen ◽  
KaiJun Jiang ◽  
DaKui Feng
Keyword(s):  
Degrees Of Freedom ◽  
Transfer Functions ◽  
Resistance Coefficient ◽  
Full Scale ◽  
Body Motion ◽  
Ship Motions ◽  
Added Resistance ◽  
Viscous Effects ◽  
Head Waves ◽  
And Performance

It is critical to be able to estimate a ship’s response to waves, since the added resistance and loss of speed may cause delays or course alterations, with consequent financial repercussions. Traditional methods for the study of ship motions are based on potential flow theory without viscous effects. Results of scaling model are used to predict full-scale of response to waves. Scale effect results in differences between the full-scale prediction and reality. The key objective of this study is to perform a fully nonlinear unsteady RANS simulation to predict the ship motions and added resistance of a full-scale KRISO Container Ship. The analyses are performed at design speeds in head waves, using in house computational fluid dynamics (CFD) to solve RANS equation coupled with two degrees of freedom (2DOF) solid body motion equations including heave and pitch. RANS equations are solved by finite difference method and PISO arithmetic. Computations have used structured grid with overset technology. Simulation results show that the total resistance coefficient in calm water at service speed is predicted by 4 .68% error compared to the related towing tank results. The ship motions demonstrated that the current in house CFD model predicts the heave and pitch transfer functions within a reasonable range of the EFD data, respectively.

scholarly journals On the Comparative Seakeeping Analysis of the Full Scale KCS by Several Hydrodynamic Approaches

2020 ◽  
Vol 8 (12) ◽  
pp. 962
Author(s):  
Florin Pacuraru ◽  
Leonard Domnisoru ◽  
Sandita Pacuraru
Keyword(s):  
Global Economy ◽  
Domain Boundary ◽  
Ship Motions ◽  
Ocean Engineering ◽  
Regular Waves ◽  
Transport Channel ◽  
Navier Stokes Equation ◽  
Seakeeping Performance ◽  
Strip Theory ◽  
Head Waves

The main transport channel of the global economy is represented by shipping. Engineers and hull designers are more preoccupied in ensuring fleet safety, the proper operation of the ships, and, more recently, compliance with International Maritime Organization (IMO) regulatory incentives. Considerable efforts have been devoted to in-depth understanding of the hydrodynamics mechanism and prediction of ship behavior in waves. Prediction of seakeeping performances with a certain degree of accuracy is a demanding task for naval architects and researchers. In this paper, a fully numerical approach of the seakeeping performance of a KRISO (Korea Research Institute of Ships and Ocean Engineering, Daejeon, South Korea) container ship (KCS) container vessel is presented. Several hydrodynamic methods have been employed in order to obtain accurate results of ship hydrodynamic response in regular waves. First, an in-house code DYN (Dynamic Ship Analysis, “Dunarea de Jos” University of Galati, Romania), based on linear strip theory (ST) was used. Then, a 3D fully nonlinear time-domain Boundary Element Method (BEM) was implemented, using the commercial code SHIPFLOW (FLOWTECH International AB, Gothenburg, Sweden). Finally, the commercial software NUMECA (NUMECA International, Brussels, Belgium) was used in order to solve the incompressible unsteady Reynolds-averaged Navier–Stokes equation (RANSE) flow at ship motions in head waves. The results obtained using these methods are represented and discussed, in order to establish a methodology for estimating the ship response in regular waves with accurate results and the sensitivity of hydrodynamical models.

scholarly journals Prediction of Ship Motions and Added Resistance in Head Waves Base on Linera Strip Theory

2019 ◽  
Vol 8 (2S10) ◽  
pp. 705-709
Keyword(s):  
Ship Design ◽  
Wave Parameter ◽  
Ship Motions ◽  
Wave Forces ◽  
Sea Waves ◽  
Added Resistance ◽  
Ship Routing ◽  
Strip Theory ◽  
Head Waves ◽  
Calculation Results

Prediction of ship motions and added resistance is an importance step in the ship design phases and considerable researches are related to this subject. It plays a unique role in main seakeeping characteristics such as maximum ship speed in sea waves, voluntary and involuntary speed reduction due to wave forces and added resistance as well as ship safety and ship routing, which affect transportation time, fuel consumption and total cost. The effects of environmental condition on calculation results is analyzed by performing some calculation with different wave parameter of JONSWAP spectra. The calculation results for the DTMB vessel are examined by the comparisons with experimental data carried out at Ship Design and Research Centre's towing tank in Poland, and show good agreement, which demonstrates the ability of the present method to assess seakeeping characteristics at the initial ship design phases. The calculation is performed by using the commercial software MAXSURF.

Some Extensions of the Classical Approach to Strip Theory of Ship Motions, Including the Calculation of Mean Added Forces and Moments

1978 ◽  
Vol 22 (01) ◽  
pp. 1-19 ◽  
Author(s):  
Theodore A. Loukakis ◽  
Paul D. Scfavounos
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Dynamical Theory ◽  
Forced Oscillations ◽  
Ship Motions ◽  
Regular Waves ◽  
Strip Theory ◽  
Calm Water ◽  
Exciting Forces ◽  
New Formulation

The application of the dynamical theory to the problem of a ship moving with constant forward speed on a free surface has been extended to include the exciting forces in oblique regular waves. As a result, it has become possible to derive a new formulation for the equations of motion, for a ship moving with five degrees of freedom. The application of the same theory has yielded formulas for the calculation of the mean added resistance and drift force in oblique regular waves and the calculation of all mean forces and moments for the forced oscillations of a ship in calm water.

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.

Sign in / Sign up

Export Citation Format

Share Document