Results 141 to 150 of about 268 (171)

On a Ship Track-Keeping Controller with Roll Damping Capability

IFAC Proceedings Volumes, 2001
Abstract In this paper the problem of ship trajectory tracking with ॉ-accuracy is considered. Results presented are based on a three-degrees-of-freedom model with full dynamic interaction between motions in roll, sway and yaw. The aim of control is to minimise the influence of wave disturbances on roll motion and to track with ॉ-accuracy a ship ...
Dorota Lozowicka, Antonio Tiano, Adam Lozowicki   +2 more
openaire   +1 more source

Melnikov analysis for a ship with a general roll-damping model

Nonlinear Dynamics, 1994
In the framework of a general roll-damping model, we study the influence of different damping models on the nonlinear roll dynamics of ships through a detailed Melnikov analysis. We introduce the concept of the Melnikov equivalent damping and use phase-plane concepts to obtain simple expressions for what we call the Melnikov damping coefficients.
M. Bikdash, B. Balachandran, A. Navfeh
openaire   +1 more source

Empirical calculation of roll damping for ships and barges

Ocean Engineering, 2001
Abstract For a large floating structure in waves, the damping is computed by the linear diffraction/radiation theory. For most degrees of freedom, this radiation damping is adequate for an accurate prediction of the rigid body motions of the structure at the wave frequencies.
openaire   +1 more source

Damping characteristic study of ship bionic anti-rolling device

Ships and Offshore Structures, 2020
According to the shape and structure characteristics of ray in the ocean, a passive damping anti-rolling device was designed for fishing boats, platforms on the ocean, pontoon, heavy lift vessel an...
Kaihan Yao, Kunpeng Zhang, Yuanchao Zhang, Fangjun You, Chiming Wang, Jingjing Xiao, Daoheng Sun   +6 more
openaire   +1 more source

The effect of nonlinear damping and restoring in ship rolling

Ocean Engineering, 2000
Many researchers have studied a wide range of nonlinear equations of motion describing a ship rolling in waves. In this study, a form of nonlinear equation governing the motion of a rolling ship subjected to synchronous beam waves is suggested and solved by the generalized Duffing's method in the frequency domain. Various representations of damping and
openaire   +1 more source

Ship Roll Damping Coefficient Prediction Using CFD

Journal of Ship Research, 2019
For a ship undergoing roll motion at a resonance frequency, the roll restoring moment and virtual moment of inertia counteract each other and only the damping moment resists the roll exciting moments. Hence, accurate computation of the roll damping moment improves the roll motion prediction.
Seyed Sadra Kianejad, Hossein Enshaei, Jonathan Duffy, Nazanin Ansarifard, Dev Ranmuthugala   +4 more
openaire   +1 more source

Numerical prediction of roll damping of ships with and without bilge keel

Ocean Engineering, 2019
Abstract Estimation of roll damping of ships from free roll decay experiments or using appropriate semi-empirical formulae is a common practice. The total roll damping of a ship or a barge can be strongly nonlinear consisting of linear and nonlinear components; especially when bilge keel is fitted to the hull as a damping device and also when angles ...
Mohsin A.R. Irkal, S. Nallayarasu, S.K. Bhattacharyya   +2 more
openaire   +1 more source

Nonlinear analysis for a ship with a general roll-damping model

Physica Scripta, 2007
The qualitative behaviour of the response of a ship rolling in longitudinal waves whose amplitude or frequency (parameters) are slowly varied is presented. An analytical and numerical technique is used to predict the qualitative change taking place in the stable solutions of a ship model as one of the parameters is slowly changed.
openaire   +1 more source

Non-Linear Effects of Roll Damping Tanks on Ship Motions

Volume 2: Ocean Engineering and Polar and Arctic Sciences and Technology, 2006
This article describes the application of two numerical methods of computing the flow in u-tube and free surface roll damping tanks. These methods account for the most important non-linear effects in tank flows. i) The programs based on these methods are integrated in a non-linear time simulation strip program. ii) Response curves of tanks are computed
Carsten Schumann, Ricardo Pereira
openaire   +1 more source

Ship Roll Damping Using the Rudder and Stabilising Fins

IFAC Proceedings Volumes, 1992
Abstract The problem addressed is that of improving ship roll damping using the rudder and stabiliser fins in an integrated control configuration. Results from a digital computer simulation study are presented which demonstrate the enhanced roll damping which can be achieved by using control surfaces in concert.
openaire   +1 more source