Ship Form Effects on the Forces and Moment on a Stationary Ship Induced by a Passing Ship
TL;DR: In this paper, the hydrodynamic interaction forces and moment acting on a moored ship due to the passage of another ship in its proximity are studied by considering the influence of ship form against the idealized approach of the use of parabolic sectional area distribution.
About: This article is published in IFAC Proceedings Volumes.The article was published on 2003-09-01. It has received 5 citations till now. The article focuses on the topics: Response amplitude operator & Ship stability.
Citations
More filters
TL;DR: In this paper, the influence of ship form against the idealized approach of the use of parabolic sectional area distribution was investigated by considering the influence on the hydrodynamic interaction forces/moments acting on a moored ship due to the passage of another ship in its proximity.
13 citations
Journal Article•
TL;DR: In this article, the hydrodynamic interaction forces acting on a moored ship due to the passage of another ship are estimated using slender body assumptions using an assumed parabolic sectional area distribution for the ship and also using the real ship form.
Abstract: The hydrodynamic interaction forces acting on a moored ship due to the passage of another ship is estimated using slender body assumptions. The computations are performed for an assumed parabolic sectional area distribution for the ship and also using the real ship form. Subsequently the equations of motion of the moored ship are solved to study the forces on the mooring ropes for different rope constants. The obtained hydrodynamic interaction and mooring rope forces are compared with known experimental/ theoretical values. Interaction effects between ships arise from changes in the pressure fields surrounding the ships. These effects become more significant when they operate in proximity to each other, such as when operating in a harbour, a channel, a canal, fair way or in other confined waters. The hydrodynamic interaction forces, which are amplified in close encounters in restricted waters, should be properly understood to assess the eventuality on a vessel’s mooring lines and to avoid the probable risk of collision. There are incidents where a ship moored in a quay starts moving by breaking the mooring lines and also a lot of cases of collision with a passing ship due to the hydrodynamic interaction between them. Since there is a phase lag between the mooring rig failure and the interaction forces and moment, the effect may be noticed only after the passing vessel has moved away. So, it is evident that passing ship effects can be disastrously high to a moored ship unless it is properly moored. So another important area where proper attention is required due to the hydrodynamic interactive effects is the design of mooring and fender systems.
6 citations
Cites methods from "Ship Form Effects on the Forces and..."
...The hydrodynamic interaction problem between moored and passing ships was studied by Krishnankutty [6,7] and by Varyani and Krishnankutty [8,9] using the slender body theory with singularity distribution technique for the computation of forces in surge and sway modes and yaw moment acting on moored vessel....
[...]
01 Jan 2012
TL;DR: In this paper, the authors present an overview of the tests that have been carried out and discuss the effect of swinging versus passing and the impact of meeting vessels on the moored ships.
Abstract: The Antwerp Port Authority is particularly interested in the investigation of specific cases of interaction between passing and moored vessels that take account of the specific situation in the harbour of Antwerp. To cope with different questions a captive manoeuvring test program has been carried out at the towing tank for manoeuvres in shallow water, for different under keel clearances and dock widths. The present paper will give an overview of the tests that have been carried out and will specifically discuss the effect of swinging versus passing and the effect of meeting vessels on the moored ships.
4 citations
Journal Article•
TL;DR: In this paper, the elasticity of a mooring rope depends on the material, construction, length and diameter of the rope and the effect of these factors on drift motions of the moored ship.
Abstract: Harbour is a region where ships are moored in a relatively calm environment, but it is a region with dense ship traffic. Present study deals with analysis of forces and moment on a moored ship induced by a ship passing-by. The elasticity of a mooring rope depends on the material, construction, length and diameter of the rope. Fibre ropes are more elastic than steel ones. The effect of these factors of mooring system on drift motions of the moored ship are presented here for different combinations of mooring rope materials and lengths for a selected vessel combination and operating condition with the breaking strength requirement keeping constant. The mooring system used is a linear one and the coupling between modes of motion of the moored ship is neglected.
3 citations
Cites background from "Ship Form Effects on the Forces and..."
...The hydrodynamic interaction forces acting on a moored ship due to the passage of another ship, based on slender body assumptions and singularity distribution, have been studied by different authors [3,9] including the influence of ship form [4,7]....
[...]
01 Jan 2010
TL;DR: In this article, the hydrodynamics interaction between a Tug and a tanker ship model, using Computational Fluid Dynamics (CFD) code was formed to calculate the hydroynamics interactions force coefficients and the associated wave pattern generated by the two vessels.
Abstract: Study of the hydrodynamics interaction between a tu g and a tanker ship model, using Computational Fluid Dynamics (CFD) code was p erformed to calculate the hydrodynamics interaction force coefficients and th e associated wave pattern generated by the two vessels. The study was conducted for two veloci ties (full scale) of 4.0 and 6.0kn and depth-draught ratio 1.1 and 1.51, respectively. Two set of variables were considered, which are the longitudinal offset, and the lateral distan ce. A simulation of the Tug sailing freely was conducted to the pure interaction loads with or wit hout deformable free surface. Several CFD models were carried out using viscous and inviscid fluid flow taking into account the free surface.
2 citations
References
More filters
TL;DR: In this paper, the unsteady hydrodynamic interaction of two bodies moving in a shallow fluid is examined by applying slender-body theory and the degree of coupling is related to a bottom-clearance parameter.
Abstract: The unsteady hydrodynamic interaction of two bodies moving in a shallow fluid is examined by applying slender-body theory. The bodies are assumed to be in each other's far field and the free surface is assumed to be rigid. By matched asymptotics, the inner and outer problems are formulated and a pair of coupled integro-differential equations for determining the unknown cross flows is derived. The degree of coupling is shown to be related to a bottom-clearance parameter. Expressions are given for the unsteady sinkage force, trimming moment, sway force, and yaw moment. Numerical calculations for two weakly coupled cases are presented. One corresponds to the interaction of a stationary body with a passing one, the other to the interaction of two bodies moving in a steady configuration. Theoretical results are compared with existing experimental data.
62 citations
01 Jan 1974
TL;DR: In this article, the effects of passing distance, speed and size of a passing ship on the lateral motion of a moored vessel were investigated and the effect of the stiffness of the mooring system on lateral motion was investigated.
Abstract: Deals with some preliminary results of model tests carried out in the wave and current laboratory of the Netherlands Ship Model Basin to determine the external forces on a tanker, moored in shallow water, as a result of the passage of a large tanker shaped vessel. The main effects of passing distance, speed and size of the passing tanker are shown. It will be discussed how the response of the moored vessel may be calculated from the exciting forces measured. A calculation of the lateral motion of a tanker moored by means of linear springs illustrates the calculation procedure and supplies interesting information concerning the effect of the stiffness of the mooring system on the lateral mooring forces.
55 citations