Numerical study of forced roll oscillation of FPSO with bilge keel

Avalos, Gustavo O. Guarniz; Wanderley, Juan B. V.

doi:10.1016/j.oceaneng.2017.10.034

Cited by 13 publications

(3 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bilge keels are widely used anti-rolling devices for ships because of their simple structure, low manufacturing cost, and significant roll reduction effect. Avalos et al [4] simulated free and forced roll oscillation damping of the middle section of Floating Production Storage and Offloading (FPSO) with bilge keels. The equation of motion is governed by incompressible two-dimensional Navier-Stokes equations and solved using the finite volume method and the upwind TVD scheme of Roe-Sweby.…”

Section: Introductionmentioning

confidence: 99%

Controlling period-doubling route to chaos phenomena of roll oscillations of a biased ship in regular sea waves

Kumar

Mitra

2023

Preprint

View full text Add to dashboard Cite

Dynamics, control, and stability of roll oscillations of a biased ship in regular sea waves are investigated. The ship under roll oscillation is modeled as the classical Helmholtz-Duffing oscillator with strongly nonlinear asymmetric restoring moment characteristics. The incremental harmonic balance (IHB) method, amended with a pseudo-arc-length continuation approach, is employed to obtain the uncontrolled and controlled frequency responses. The primary and subharmonic responses of the uncontrolled system are examined through the period-doubling route to chaos path. The same ship roll model is then investigated under state feedback control with time delay. In the control scheme, a moving weight is actuated by the delay controller to generate the anti-rolling moment. The stability of periodic responses is studied using the semi-discretization method with extended Floquet theory. Bifurcation points on periodic response branches are identified from the eigenvalue study. The effect of gains and time delay in the feedback loop in controlling the primary and subharmonic responses is investigated. Several chaotic responses obtained through period-doubling route to chaos paths are successfully controlled. Stable, periodic, and steady-state solutions obtained from the IHB method are verified by numerical integration (NI) of the equation of motion as and when applicable. Solutions are aided with phase portrait, Poincaré map, time history, and Fourier spectrum for better clarity. It is shown that appropriate selections of control parameters can effectively reduce the roll amplitude to a great extent with the improved measure of stability.

show abstract

Section: Introductionmentioning

confidence: 99%

Controlling period-doubling route to chaos phenomena of roll oscillations of a biased ship in regular sea waves

Kumar

Mitra

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…The influence of the draft and amplitude of oscillation on the bilge keel force and hull pressure distribution was considered and compared with the standard empirical method proposed by Ikeda et al (1977). Avalos and Wanderley (2018) developed a computational code to simulate forced roll oscillation of a middle section of FPSO with different bilge keels types. Their work showed the effect of the generated vortices on the pressure distribution around the mid-section.…”

Section: Introductionmentioning

confidence: 99%

Influence of bilge-keel configuration on ship roll damping and roll response in waves

et al. 2020

View full text Add to dashboard Cite

“…The shape and width of the keel bilges has been known to affect the damping coefficient of a boat [4][5][6][7][8][9][10][11][12]. The more vortices a bilge keel can generate the higher roll damping it can achieve [5].…”

Section: Introductionmentioning

confidence: 99%

Analysis on Rolling Damping of a Conventional Boat fitted with T-shaped Bilge Keels

et al. 2018

View full text Add to dashboard Cite

This work presents a numerical study on the effect of T-shaped bilge keels on the roll damping of a conventional boat. A scaled boat model with the same dimensions as that of Irkal et al. [2] was fitted with two T-shaped bilge keels at the edges of the model. Computational Fluid Dynamics method was employed to simulate the roll decay motion of the boat. The motion of the boat is captured using a 6DOF model and the Overset grid approach. Comparison was performed on the damping characteristics of the conventional I-shaped and the T-shaped bilge keels. In addition, the impact of the aspect ratio of the keel bilges on the roll damping of the boat was evaluated. It was found that the bilge keel aspect ratio influences the damping coefficient non-linearly. Sufficiently large aspect ratio, i.e. an aspect ratio greater than 2, is necessary in order to obtain an effective damping on the peak angle.

show abstract

Numerical study of forced roll oscillation of FPSO with bilge keel

Cited by 13 publications

References 9 publications

Controlling period-doubling route to chaos phenomena of roll oscillations of a biased ship in regular sea waves

Controlling period-doubling route to chaos phenomena of roll oscillations of a biased ship in regular sea waves

Influence of bilge-keel configuration on ship roll damping and roll response in waves

Analysis on Rolling Damping of a Conventional Boat fitted with T-shaped Bilge Keels

Contact Info

Product

Resources

About