535
1
INTRODUCTION
The main commonly discussed features of maritime
transport are usually its safety and effectiveness.
Amongthemtheshipssafetyissuesarecrucialfrom
the operational point of view and they can be
considered as one of the most prospective technical
affairs. One of the most critical features of seagoing
ships
relatedtohersafetyistheirstability.
Ship stability is a term used to describe the
tendencyofashipto returnbacktoherequilibrium
when she is inclined from an upright position [5].
Since the initial position of a ship is not always
uprightone,themore practical
definitionstatesthat
the stability is a feature enabling to perform, when
remaining in determined position, the task she is
constructed for. The complementary definitions lead
topointoutthatthestabilityofashipisanelementof
heroperationalsafetyqualifyingfactors.
The seagoing vessel’s stability calculation and
evaluation
madeonboard nowadays is based onthe
prescriptive stability criteria published by the ship’s
classification societies [5]. These criteria are mainly
based on the A749(18) Resolution of International
MaritimeOrganization.Theresolutionandtheirlater
amendments are known as the Intact Stability Code
[4].
Theshipstabilitycriteriaqualifythe
shapeofthe
rightingarmcurve.Inaddition,theweathercriterion
is to ensure the sufficient stability of a ship to
withstand the severewindguestsduringrolling[4].
Althoughtheweathercriterionreflectsaverysimple
modelofdynamicship’sbehavior,thestaticstability
curve is used. Anyway, the weather
criterion is the
only, which is partly based on the model of heeling
phenomenonnotonlyonthestatisticdata,whilethe
remaining criteria are based on the statistics of
historical disasters only [3]. The modern and still
developing approach towards ship stability
A Method of Assessment of the Liquid Sloshing
Impact on Ship Transverse Stability
P.Krata
GdyniaMaritimeUniversity,Gdynia,Poland
ABSTRACT:Liquidsloshingphenomenontakingplaceinpartlyfilledships’tanksdirectlyaffectsthestability
ofavessel. However,onlystaticcalculations are carriedoutonboard ships nowadays and statictransferof
liquid weight is taken into account in the course of routine stability calculation. The paper is focused on a
dynamicheelingmomentduetoliquidsloshingintanksonboardships.Thesetofnumericalsimulationsof
liquidsloshingtakingplaceinmovingtanksiscarriedout.Therealisticrangeofgeometricparametersistaken
intoaccount.TheconductedCFDsimulationsareexperimentallyverified.Finally,themethodofanassessment
of the liquid sloshing impact on ship transverse stability is worked out. The key point of the method is a
dynamiccoefficientdescribingrelationoftheresearcheddynamicheelingmomentandthequasi staticonein
termsofdynamicstabilityofavesselwhichisrelatedtotheweathercriterionof
shipstabilityassessment.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 8
Number 4
December 2014
DOI:10.12716/1001.08.04.07
536
qualification is an implementation of performance
based stability criteria in the future. They are based
mainlyon theriskassessment [5]however,itis still
farfromcommonuseonboardships.
Regardless the approach towards ship stability
evaluation, the physical background of phenomena
takingplaceonboardoughttobetaken
intoaccount.