Roll Damping Simulations of an Offshore Heavy Lift DP3 Installation Vessel Using the CFD Toolbox OpenFOAM

2020 ◽  
Author(s):  
Brecht Devolder ◽  
Florian Stempinski ◽  
Arjan Mol ◽  
Pieter Rauwoens
Keyword(s):  
Boundary Element ◽  
Damping Coefficient ◽  
Navier Stokes ◽  
Roll Motion ◽  
Viscous Effects ◽  
Roll Damping ◽  
Two Phase ◽  
Damping Behavior ◽  
External Moment ◽  
Heavy Lift

Abstract In this work, the roll damping behavior of the offshore heavy lift DP3 installation vessel Orion from the DEME group is studied. Boundary element codes using potential flow theory require a roll damping coefficient to account for viscous effects. In this work, the roll damping coefficient is calculated using the Computational Fluid Dynamics (CFD) toolbox OpenFOAM. The two-phase Navier-Stokes fluid solver is coupled with a motion solver using a partitioned fluid-structure interaction algorithm. The roll damping is assessed by the Harmonic Excited Roll Motion (HERM) technique. An oscillating external moment is applied on the hull and the roll motion is tracked. Various amplitudes and frequencies of the external moment and different forward speeds, are numerically simulated. These high-fidelity full-scale simulations result in better estimations of roll damping coefficients for various conditions in order to enhance the accuracy of efficient boundary element codes for wave-current-structure interactions simulations.

Ship Roll Motion Damping Using Bilge Keels – A Detailed CFD Investigation

2015 ◽  
Author(s):  
Joshua Counsil ◽  
Kevin McTaggart ◽  
Dominic Groulx ◽  
Kiari Boulama
Keyword(s):  
Experimental Studies ◽  
The Body ◽  
Navier Stokes ◽  
Roll Motion ◽  
Empirical Methods ◽  
Viscous Effects ◽  
Vortex Interactions ◽  
Ship Roll ◽  
Semi Empirical ◽  
Bilge Keel

A study has been undertaken to test the value of unsteady Reynolds-averaged Navier-Stokes (URANS) and traditional semi-empirical methods in the face of complex ship roll phenomena, and provide insight into the selection of bilge keel span for varying roll amplitudes. The computational fluid dynamics (CFD) code STAR-CCM+ is employed and two-dimensional submerged bodies undergoing forced roll motion are analyzed. The spatial resolution and timestepping scheme are validated by comparison with published numerical and experimental studies. The model is then applied to a fully-submerged circular cylinder with bilge keels of varying span and undergoing roll motion at varying angular amplitudes. Extracted hydrodynamic coefficients indicate that in general, increasing displacement amplitude and bilge keel span yields increased added mass and increased damping. The relationship is complex and highly dependent upon vortex interactions with each other and the body. The semi-empirical methods used for comparison yield good predictions for simple vortex interactions but fail where viscous effects are strong. Hence, URANS methods are shown to be necessary for friction-dominated flows while semi-empirical methods remain useful for initial design considerations.

Partially Cavitating Hydrofoils: Experimental and Numerical Analysis*

2000 ◽  
Vol 44 (01) ◽  
pp. 40-58
Author(s):  
Christian Pellone ◽  
Thierry Maître ◽  
Laurence Briançon-Marjollet
Keyword(s):  
Numerical Models ◽  
Lift Coefficient ◽  
Pressure Coefficient ◽  
Navier Stokes ◽  
Viscous Effects ◽  
Local Pressure ◽  
Two Phase ◽  
Complete Study ◽  
Flow Configurations ◽  
Potential Methods

The numerical modeling of partially cavitating foils under a confined flow configuration is described. A complete study of previous numerical models highlights that the presence of a turbulent and two-phase wake, at the rear of the cavity, has a nonnegligible effect on the local pressure coefficient, the cavitation number, the cavity length and the lift coefficient; hence viscous effects must be included. Two potential methods are used, each being coupled with a calculation of the boundary layer developed downstream of the cavity. So, an "open cavity" numerical model, as it is called, was developed and tested with two types of foil: a NACA classic foil and a foil of which the profile is obtained performing an inverse calculation on a propeller blade test section. On the other hand, under noncavitating conditions, for each method, the results are compared with the results obtained by the Navier-Stokes solver "FLUENT." The cavitating flow configurations presented herein were carried out using the small hydrodynamic tunnel at Bassin d'Essais des Carènes [Val de Reuil, France]. The results obtained by the two methods are compared with experimental measurements.

A Roll Damping Analysis of a Standard US Naval Hull Form (DTMB 5415)

2021 ◽  
Vol 163 (A1) ◽  
pp. 79-86
Author(s):  
L F Hu ◽  
Q T Gong ◽  
Z M Yuan ◽  
X Y Wang ◽  
J X Duan
Keyword(s):  
Numerical Simulation ◽  
Vof Method ◽  
Navier Stokes ◽  
Roll Motion ◽  
Ship Motions ◽  
Stability Criteria ◽  
Fluid Interface ◽  
Roll Damping ◽  
Hull Form ◽  
Us Navy

Accurate prediction of roll damping is important in calculating the roll motion of a ship. This paper presents a roll decay analysis of an intact US Navy Destroyer hull form (DTMB 5415) using a Navier–Stokes (NS) solver with the volume of fluid (VOF) method. Dynamic overset mesh techniques were employed to handle mesh updating required to obtain transient ship motions. The VOF method was used to capture the fluid interface. The effect of turbulence was considered by means of a k-w and a k-e model. A sensitivity analysis was conducted, in terms of the grid, timesteps and degree of freedom. The roll decay results of the numerical simulation have been compared with those of prior physical model testing (Gokce and Kinaci, 2018), and the different roll decay responses used to predict the roll damping. It is intended that this research be a useful step towards establishing intact ship stability criteria, as part of current research.

scholarly journals Numerical Assessment of Roll Motion Characteristics and Damping Coefficient of a Ship

2018 ◽  
Vol 6 (3) ◽  
pp. 101 ◽  
Author(s):  
S.S. Kianejad ◽  
Jaesuk Lee ◽  
Yi Liu ◽  
Hossein Enshaei
Keyword(s):  
Degrees Of Freedom ◽  
Resonance Condition ◽  
Excitation Frequency ◽  
Roll Motion ◽  
Viscous Effects ◽  
Roll Damping ◽  
Numerical Assessment ◽  
Motion Characteristics ◽  
The Moment ◽  
Cfd Method

Accurate calculation of the roll damping moment at resonance condition is essential for roll motion prediction. Because at the resonance condition, the moment of inertia counteracts restoring moment and only the damping moment resists increase in the roll angle. There are various methods to calculate the roll damping moment which are based on potential flow theory. These methods have limitations to taking into account the viscous effects in estimating the roll motion, while, CFD as a numerical method is capable of considering the viscous effects. In this study, a CFD method based on a harmonic excited roll motion (HERM) technique is used to compute the roll motion and the roll damping moment of a containership’s model in different conditions. The influence of excitation frequency, forward speed and degrees of freedom at beam-sea and oblique-sea realizations are considered in estimating the roll damping coefficients. The results are validated against model tests, where a good agreement is found.

A RANS Based Method for the Estimation of Ship Roll Damping With Forward Speed

2004 ◽  
Author(s):  
Kumar B. Salui ◽  
Vladimir Shigunov ◽  
Dracos Vassalos
Keyword(s):  
High Speed ◽  
Turbulence Modeling ◽  
Finite Difference Methods ◽  
Computer Hardware ◽  
Navier Stokes ◽  
Roll Motion ◽  
Ship Motions ◽  
Viscous Effects ◽  
Flow Models ◽  
Ship Roll

For the prediction of ship roll motion, viscous effects must be taken into account. Several methods, experimental and theoretical, have previously been used to calculate hydrodynamic forces in roll motion. Theoretical methods applied so far to this problem have been based mainly on potential flow models, which cannot account for viscous effects adequately or need pre-defined flow separation like vortex methods. Recent development of computer hardware enables application of methods based on flow field discretisation such as finite-difference methods to solution of problems of practical ship design such as ship motions and control. In the present study, a Reynolds-Averaged Navier-Stokes solver is used to calculate hydrodynamic loads during forced roll motion at different Froude numbers. The solution method adopted is based on unstructured finite-volume discretisation with collocated arrangement of flow variables. A pressure-correction algorithm (SIMPLE) is used for the pressure-velocity coupling. A standard k–ε model is used for the turbulence modeling. An advanced differencing scheme called high-resolution interface capturing (HRIC) is used for accurate resolution of the free surface in the scope of a multiphase-type description. A high-speed hard chine vessel with and without skeg is studied. Close agreement is found between the present calculations and experimental results.

Simulation of the Dynamic Response of a Sloshing Liquid to Horizontal Movements of the Tank

2014 ◽  
Author(s):  
Anaïs Brandely ◽  
Jean-Sébastien Schotté ◽  
Emmanuel Lefrançois ◽  
Benjamin Hagege ◽  
Roger Ohayon
Keyword(s):  
Free Surface ◽  
Dynamic Response ◽  
Stokes Equations ◽  
Numerical Approach ◽  
Navier Stokes ◽  
Phase Flow ◽  
Viscous Effects ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Sst Turbulence Model

The dynamic response of a sloshing liquid to horizontal movements of a rectangular tank with a small amplitude is studied here by a numerical approach issued from a commercial CFD code. This numerical model solves Navier-Stokes equations considering a two-phase flow. In order to check the localized turbulence effects on the global fluid behavior, the averaged Navier-Stokes equations are solved with laminar option and with a k–ω SST turbulence model. The Volume Of Fluid (VOF) method is adopted to track the distorted free surface. The previous CFD solution is compared with a linearized approach based on the potential flow theory taking into account viscous effects. This model considers a single phase flow and is much less expensive in CPU time, especially thanks to the use of modal projection techniques. Both models are validated and applied on several cases. Free surface sloshing elevation and global forces, obtained for various excitation amplitudes and frequencies, are compared. Perfect and viscous liquids are considered.

A Two-Dimensional Numerical Simulation of Roll Damping Decay of a FPSO Using the Upwind TVD Scheme of Roe-Sweby

2012 ◽  
Author(s):  
Gustavo O. Guarniz Avalos ◽  
Juan B. V. Wanderley
Keyword(s):  
Stokes Equations ◽  
Navier Stokes ◽  
Tvd Scheme ◽  
Viscous Effects ◽  
Roll Damping ◽  
Navier Stokes Equations ◽  
Decay Test ◽  
Spurious Oscillations ◽  
Volume Method ◽  
Bilge Keel

The study of roll damping is investigated for a Floating Production Storage and Offloanding (FPSO). For this purpose, a roll decay test of FPSO is simulated by means of the numerical solution of the slightly compressible Navier-Stokes equations in 2D. The governing equations are solved using the finite volume method and the upwind TVD scheme of Roe-Sweby. The roll damping for rectangular hulls is dominated by viscous effects. Strong vortices are formed around the bilge keel. Hence, in this zone, there is a discontinuity of pressure that the TVD scheme will resolve and capture the physics of the phenomenon without spurious oscillations. The numerical results are compared with experimental data for validating the numerical scheme implemented.

Design of a Pendulum-type Anti-rolling System for USSV and Verification Based on Roll Damping Coefficient

2019 ◽  
Vol 56 (6) ◽  
pp. 550-558
Author(s):  
Woo-Seok Jin ◽  
Yong-Ho Kim ◽  
Jun-Ho Jung ◽  
Kwangkook Lee ◽  
Dong-Hun Kim
Keyword(s):  
Damping Coefficient ◽  
Roll Damping ◽  
Rolling System

Numerical Modeling of Evolution of Boundary Between Incompressible Gas and Liquid in Two-Dimensional Region

2006 ◽  
Vol 4 ◽  
pp. 224-236
Author(s):  
A.S. Topolnikov
Keyword(s):  
Numerical Modeling ◽  
Interphase Boundary ◽  
Incompressible Liquid ◽  
Stokes Equations ◽  
Numerical Code ◽  
Navier Stokes ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Incompressible Media ◽  
Good Agreement

The paper is devoted to numerical modeling of Navier–Stokes equations for incompressible media in the case, when there exist gas and liquid inside the rectangular calculation region, which are separated by interphase boundary. The set of equations for incompressible liquid accounting for viscous, gravitational and surface (capillary) forces is solved by finite-difference scheme on the spaced grid, for description of interphase boundary the ideology of Level Set Method is used. By developed numerical code the set of hydrodynamic problems is solved, which describe the motion of two-phase incompressible media with interphase boundary. As a result of numerical simulation the solutions are obtained, which are in good agreement with existing analytical and experimental solutions.

scholarly journals Experimental and Numerical Study on Water Filling and Air Expelling Process in a Pipe with Multiple Air Valves under Water Slow Filling Condition

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2511
Author(s):  
Jintao Liu ◽  
Di Xu ◽  
Shaohui Zhang ◽  
Meijian Bai
Keyword(s):  
Numerical Model ◽  
Stokes Equations ◽  
Numerical Study ◽  
Practical Method ◽  
Navier Stokes ◽  
Physical Processes ◽  
Two Phase ◽  
Saint Venant Equations ◽  
Water Filling ◽  
Air Valve

This paper investigates the physical processes involved in the water filling and air expelling process of a pipe with multiple air valves under water slow filling condition, and develops a fully coupledwater–air two-phase stratified numerical model for simulating the process. In this model, the Saint-Venant equations and the Vertical Average Navier–Stokes equations (VANS) are respectively applied to describe the water and air in pipe, and the air valve model is introduced into the VANS equations of air as the source term. The finite-volume method and implicit dual time-stepping method (IDTS) with two-order accuracy are simultaneously used to solve this numerical model to realize the full coupling between water and air movement. Then, the model is validated by using the experimental data of the pressure evolution in pipe and the air velocity evolution of air valves, which respectively characterize the water filling and air expelling process. The results show that the model performs well in capturing the physical processes, and a reasonable agreement is obtained between numerical and experimental results. This agreement demonstrates that the proposed model in this paper offers a practical method for simulating water filling and air expelling process in a pipe with multiple air valves under water slow filling condition.

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