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1 INTRODUCTION
Fromtheviewpointofearthenvironmentprotection,
the shipping industry is required to develop and
improve energy saving ship operation technologies.
Forexample,theweatherroutingisoneoftheabove
technologies and it is often used for the navigation
planning of oceangoing merchant ships in order
to
minimizethedistancetraveledandfuelconsumption.
Theeffectivenessoftheweatherroutingontheenergy
saving mainly depends on the accuracy of the
weather forecast data and that of the propulsion
performance prediction in the actual sea where the
effectofwindandwaveonship’smotionexists.
The
weatherforecasttechnologyhasbeenimprovedyear
byyearandaneasiermethodtoobtaintheworldwide
accurate weather forecast data has been proposed
(Yokoi 2010). On the other hand, the propulsion
performance in the actual sea is usually predicted
usingtheSelf Propulsion Factors obtained by model
testsdue
tothesmallamountoffull‐scaleexperiment
dataintheactualsea(Sasaki2009,Tsujimoto2000).
In general, ship’s speed in the actual sea is low
comparedtothespeedmeasuredatthespeedtrialin
thestillwater.Inordertoimprovetheaccuracyofa
propulsionperformance
prediction,itisnecessaryto
understandtheeffectofexternaldisturbancessuchas
wind and wave on the propulsion performance
qualitatively.
It is said that the effect of the wave on the Self
Propulsion Factors are small and the propulsion
performanceunderthewaveisoftenpredictedtaking
into account both
an increase of resistance by the
wave and the propulsive efficiency reduction by a
propeller loading increase. Recently, some scholars
A Study on the Propulsion Performance in the Actual
Sea by means of Full-scale Experiments
J
.Kayano&H.Yabuki
TokyoUniversityofMarineScienceandTechnology,Tokyo,Japan
N.Sasaki
NationalMaritimeResearchInstitute,Mitaka,Japan
R.Hiwatashi
NationalInstituteforSeaTraining,Yokohama,Japan
ABSTRACT: The IMO has adopted Energy Efficiency Design Index (EEDI), Ship Energy Efficiency
Management Plan (SEEMP) and Energy Efficiency Operational Indicator (EEOI) in order to reduce GHG
emissions from international shipping. And, the shipping industry is required to develop and improve the
energy
savingshipoperationtechnologiestomeettheaboveIMOguideline.Theweatherroutingisoneofthe
energysavingnavigationtechnologiesandwidelyadoptedbyoceangoingmerchantships.Theeffectivenessof
the weather routing mainly depends on the accuracy of weather forecast data and the ship’s propulsion
performance prediction. The propulsion
performance in the actual sea is usually predicted using the Self
Propulsion Factors obtained by model tests. It is necessary to understand the propulsion performance
characteristicsintheactualseaconditionsfortheimprovementofpropulsionperformanceprediction.Fromthe
abovepointsofview,theauthorsperformedfull‐scaleexperiments
usingatrainingshipinordertoinvestigate
thepropulsionperformancecharacteristicsinthe actualsea.Thispaperdescribestheanalysisresultsonthe
characteristicsofPowerCurvesandSelfPropulsionFactorsundervariousweatherandseaconditions.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 7
Number 4
December 2013
DOI:10.12716/1001.07.04.7