Numerical Simulation of Roll Damping of a FPSO

2007 ◽  
Author(s):  
Juan B. V. Wanderley ◽  
Andre´ Ramiro ◽  
Thiago Reis ◽  
Antonio Carlos Fernandes ◽  
Carlos Levi
Keyword(s):  
Numerical Simulation ◽  
Stokes Equations ◽  
Vortex Formation ◽  
Integral Form ◽  
Quantitative Agreement ◽  
Navier Stokes ◽  
Roll Damping ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
Bilge Keel

The viscous flow problem of roll damping of a FPSO is investigated by means of numerical solution of the unsteady two-dimensional Navier-Stokes equations. The finite volume method using unstructured grid is used to solve the integral form of the governing equations. The cross section of the FPSO hull with an initial roll displacement is left free to oscillate in roll, heave and sway in an initially still fluid. The numerical simulation provides a realistic picture of the physics of the phenomenon, capturing the vortex formation around the bilge keel. The numerical results are compared with experimental data showing a fairly good qualitative and quantitative agreement of the motion damping.

Numerical Simulation of Roll Damping

2006 ◽  
Author(s):  
Juan B. V. Wanderley ◽  
Andre´ Ramiro ◽  
Thiago Reis ◽  
Antonio Carlos Fernandes ◽  
Carlos Levi
Keyword(s):  
Numerical Simulation ◽  
Stokes Equations ◽  
Vortex Formation ◽  
Integral Form ◽  
Quantitative Agreement ◽  
Navier Stokes ◽  
Roll Damping ◽  
Navier Stokes Equations ◽  
Decay Tests ◽  
Volume Method

The highly viscous flow problem of roll damping of a FPSO is investigated by means of numerical solution of the unsteady two-dimensional Navier-Stokes equations. The finite volume method using non-structured grid is used to solve the integral form of the governing equations. The cross section of the FPSO hull with an initial roll displacement is let free to oscillate in roll in an initially still fluid. The numerical simulation provides a realistic picture of the physics of the phenomenon, capturing the vortex formation around the bilge keel. Numerical results from roll free decay tests are compared with experimental data showing a fairly good qualitative and quantitative agreement of the roll damping.

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.

scholarly journals Numerical Simulation of the Solar Granulation

1980 ◽  
Vol 58 ◽  
pp. 293-299
Author(s):  
Lawrence D. Cloutman
Keyword(s):  
Numerical Simulation ◽  
Numerical Solution ◽  
Stokes Equations ◽  
Solar Physics ◽  
Quantitative Agreement ◽  
Time Dependent ◽  
Navier Stokes ◽  
Vortex Rings ◽  
Solar Granulation ◽  
Navier Stokes Equations

AbstractThe solar granulation has been simulated by numerical solution of the multidimensional, time-dependent, nonlinear Navier-Stokes equations applied to the solar atmosphere. Granules may be explained as buoyantly rising bubbles created at the level where T = 8000 K, and which have collapsed into vortex rings. The calculation is in quantitative agreement with observations and has a number of implications for solar physics and convection theory.

Numerical Simulation on Undulatory Flow of Swimming Fish

2013 ◽  
Vol 353-356 ◽  
pp. 2545-2549
Author(s):  
Xu Zhang ◽  
Xiu Bin He
Keyword(s):  
Numerical Simulation ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Time Stepping ◽  
Dual Time Stepping ◽  
Straight Line ◽  
Volume Method ◽  
Undulatory Swimming

A numerical simulation is carried out to investigate the unsteady flows over a swimming fish. The three-dimensional incompressible Navier-Stokes equations are solved using the finite volume method with artificial compressibility and dual time stepping approaches on unstructured moving grid. A realistic fish-like body is modeled, which undergoes undulatory swimming in a straight line. Both inviscid and viscous flows have been simulated to study the flow structures.

scholarly journals Simulation and visualization of formation of vortex ring, its propagation and transportation of passive scalar

2021 ◽  
pp. 182-199
Author(s):  
К.Н. Волков ◽  
В.Н. Емельянов ◽  
И.Е. Капранов
Keyword(s):  
Numerical Simulation ◽  
Vortex Ring ◽  
Stokes Equations ◽  
Passive Scalar ◽  
Navier Stokes ◽  
Time Interval ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
Traditional Approaches ◽  
Similar Theory

Рассматривается численное моделирование газодинамических процессов, сопровождающих формирование и распространение вихревых колец, получаемых при помощи поршневого генератора. Обсуждается влияние характеристик вихревого кольца на перенос пассивной примеси. Для численных расчетов применяются нестационарные уравнения Навье--Стокса, для дисукретизации которых применяется метод конечных объемов. Результаты численного моделирования позволяют получить геометрические и динамические характеристики вихревого кольца, которые соответствуют автомодельному теории вихревого кольца и экспериментальным данным. Помимо традиционных подходов к визуализации вихревых течений, основанных на построении линий уровня различных характеристик потока, для визуализации вихревых структур применяются инварианты тензора градиента скорости и метод показателей Ляпунова на конечном промежутке времени. Numerical simulation of gas-dynamic processes accompanying the formation and propagation of vortex rings obtained using a piston generator is considered. The influence of the characteristics of the vortex ring on the transfer of the passive particles is discussed. Unsteady Navier--Stokes equations are used for numerical calculations, and finite volume method is applied to their discretization. The results of numerical simulation make it possible to obtain the geometric and dynamic characteristics of the vortex ring, which correspond to the self-similar theory of the vortex ring and experimental data. In addition to traditional approaches to visualization of vortex flows based on the construction of contours of various flow quantities, invariants of the velocity gradient tensor and the method of Lyapunov exponents over a finite time interval are used to visualize vortex structures.

scholarly journals Scale Effects on a Tip Rake Propeller Working in Open Water

2019 ◽  
Vol 7 (11) ◽  
pp. 404 ◽  
Author(s):  
Lungu
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Stokes Equations ◽  
Scale Effects ◽  
Open Water ◽  
Numerical Approach ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Conference Organization ◽  
Volume Method

The scale effect on the accuracy of a numerical simulation in ship hydrodynamics represents an important issue of the propeller numerical analysis. To grasp a better understanding on the influence of this effect, an introspection on the performances of an unconventional propeller is proposed in the present study. The paper describes an investigation of the performances of a tip rake propeller recently chosen as benchmark by the International Towing Tank Conference organization (ITTC hereafter). The numerical simulation is carried out by making use of the ISIS-CFD solver, part of the FineTM/Marine package available in the NUMECA suite. The solver is based on the finite volume method to build the spatial discretization of the governing equations. The incompressible unsteady Reynolds Averaged Navier-Stokes Equations (RANSE) are solved in a global approach. Reported solutions are compared with the experimental data provided by Schiffbau-Versuchsanstalt (SVA) Potsdam GmbH to validate the accuracy of the numerical approach. Since for the full scale the experimental data could not be possible, the ITTC’78 extrapolation method-based proposed by the SVA Potsdam has been taken as a basis for comparisons and discussions. A set of remarks will conclude the paper by providing some guidelines for further approaches in terms of the particulars of the numerics that may be further employed in similar studies.

Flow Field of XCP Probe's Head and Optimization Choice of Structural Parameters

2013 ◽  
Vol 760-762 ◽  
pp. 1753-1757
Author(s):  
Hong Kun He ◽  
Shuang Qi Yang ◽  
Guang Yu Li ◽  
Hong Min Gao
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Finite Volume Method ◽  
Stokes Equations ◽  
Structural Parameters ◽  
Navier Stokes ◽  
Governing Equations ◽  
Navier Stokes Equations ◽  
Front End ◽  
Volume Method

In this study, numerical simulation of XCP probe was executed. The 3D Navier-Stokes equations were used as governing equations, and the finite volume method combining two-equations turbulence model was applied. The flow field of XCP Probe was analyzed, especially around the XCP Probe's head. The results show that the arc design of the XCP Probe's head plays an important role on the steady falling speed. In addition, when the radian is 27°, the resistance of the probe is smallest and a larger falling speed can be achieved; The electrodes of probe should be located in front end of a conduit which is in the middle of the probe.

Roll Damping Decay of a FPSO With Bilge Keel

2013 ◽  
Author(s):  
Gustavo O. Guarniz Avalos ◽  
Juan B. V. Wanderley ◽  
Antonio C. Fernandes
Keyword(s):  
Vortex Shedding ◽  
Numerical Scheme ◽  
Strong Influence ◽  
Stokes Equations ◽  
The Body ◽  
Navier Stokes ◽  
Roll Damping ◽  
Navier Stokes Equations ◽  
Decay Test ◽  
Bilge Keel

The roll damping decay 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 incompressible two-dimensional Navier-Stokes equations. The numerical results are compared with experimental data for validating the numerical scheme implemented. The simulations indicated the strong influence of the bilge radius in the damping coefficient of the FPSO section. Interesting results were obtained regarding the time series of the displacement of the body and vortex shedding around the bilge keel.

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

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