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School of Internet Program

06.01.2009

 from model Experiment

Facult of Marine Technolo Tok o University of Marine Science and

Technology

Shoji Kuniaki

Ｋｕｎｉａｋｉ ＳｈｏｊｉDepartment of Marine System Engineering

Faculty of Marine Technology

Ｔｏｋｙｏ Ｕｎｉｖｅｒｓｉｔｙ ｏｆ ｍａｒｉｎｅ Ｓｃｉｅｎｃｅ and Ｔｅｃｈｎｏｌｏｇｙ

1970 graduate Yokohama National University (Department of Naval Architecture, Faculty of Engineering)

1975 graduate the Doctoral course of the University of TokyoDoctoral Thesis: The study of motion of Mooring Ship and

Tension of Mooring Line

researching theme

Protective Systems of The Bridge Pier against Ship collision

Performance of Anti-rolling Tank

Study on High holding power anchor

Development of the city of waterfront

History of ship

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Outline of this Lecture

• In this lecture Froude’s method is explained.

This is a estimation method which evaluate

actual ship resistance from model experiment.

• At First the component of resistance is shown

and explained. Next, model experiment at the

so called towing tank which is executed

res stance test s ntro uce . s t ese resu ts,estimation method of actual ship resistance so

called Froude’s method is explained.

Components of Ship Resistance

• Total Resistance = Water Resistance + Air Resistance

• = 

Resistance + Wave Making Resistance

• Water Resistance = Frictional Resistance + Residuary

Resistance

• Water Resistance = Viscous Resistance + Wave Making

• Residuary Resistance = Eddy Resistance + Wave Making

Resistance

• Viscous Resistance = Frictional Resistance + Eddy

Making Resistance

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Wave making resistance

Resistance Test by model

It is difficult to estimate ship resistance

.

Then it is experimented now at the

experimental tank, so called

SHIP MODEL BASIN,

SHIP TOWING TANK .

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William Froude• １８１０年～１８７９年

• Who Called the Father of Modern Naval 

Architecture

• From Experience to theory

• Estimation of Actual Ship Resistance from

’• Froude Number Fn=V/(gL)1/2

• Method of Model Experiment

• Construction of Towing Tank 

Towing Tank 

 University（Japan）

• Berlin Model Basin（Germany）

• Which facilities are there?

• How experiment there?

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Experimental Tank of Yokohama National University

Yokohama University Ship Model Basin

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Profile of Yokohama University Ship Model Basin

Dimensions of Yokohama University Ship model Basin

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Towing Carriage

Self Propulsion Test

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Control Room and Resistance Dynamometer

Resistance Dynamometer

Resistance D namometer

Balancemeasurement

Trim measurementTrim measurement

Towing Carriage

Ship model

guide

Towing Rod

Counter Weight

guide

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Shaping Machine

Berlin Model Basin

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Berlin

ModelBasin

Berlin Model

Basin

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推進試験、係留試験

Flow Measurement of Aft Body

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Towing Tank 

Towing Tank （Wave Maker Side）

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Towing Carriage

Towing Tank 

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Trimming Tank Side

Casting Box

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shaping machine

Circulating Water Tank (the biggest in the world)

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Circulating Water Tank 

William Froude（１８１０－１８７９）

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Towing Tank at Torquay

Towing Tank 

Yokohama Tokyo Berlin Torquay

National University Model Towing

University Marine S. Basin Tank 

TechnologyLength １１０ｍ ５４ｍ ２５０ｍ 59.44m

Breadth ８ｍ １０ｍ ８ｍ 10.98m

Depth ３.５ｍ ２ｍ ４.８ｍ 3.05m

Speed ４.０ｍ / ｓ １.２ｍ / ｓ ９.０ｍ / ｓ 5.08m/s

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Experiment of Actual Ship

Experiment of Greyhound

Experiment of Plank Ship

Experiment of Yudachi

Evaluation of Actual Ship

• Training Ship of Faculty of Marine technology

「SHIOJI MARUⅢ」

、 .

• Scale １／30.6

• Model Measurement V=1.0m/s⇒RTM=0.2kg

• Resistance of Ship RTS

. g ＝ ｇ

0.2kg×302＝１８０ｋｇ ？

0.2kg×303＝５４００ｋｇ＝５.４ｔ ？

Speed of Actual Ship ＝1.0m/s ？

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Froude’s Method

• Water Resistance divides two components.（Water Resistance＝Frictional Resistance＋Residuary Resistance）

• Frictional Resistance of ship and model equals

Frictional resistance of flat plate.

（However that length、wetted surface area、surface

condition are same.）

• es uary res s ance o s p an mo e sproportional to 3 times of scale.

(However speed of ship and model is proportional to

root of scale.) （Froude’s low of Comparison）

Resistance Test of model of Shioji maruⅢ

• Corresponding speed：

model 1.0m/s

× 1/2＝. .

• Frictional Resistance：from resistance of plate

model 0.1kgship 1.5t

• Resistance test ：water resistance 0.2kg

• Residuary resistance of model 0.2－0.1＝0.1kg

• Residuary resistance of ship 0.1×303＝2700kg

＝2.7t

• Water Resistance of Ship 1.5＋2.7＝4.2t

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Water resistance of shipResistance coefficient

model

ship

Reynolds number

Evaluation of Ship Resistance

Ship resistance

Estimation 1

Estimation 2

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Quiz

• （１）Man who estimate the ship resistance

from model experiment.

• （２）The place where towing tank was made

at first.

• （３）The ships name of experiment of 

resistance at first.

• （４）Biggest instrument of the world in

Berlin Model Basin.

• （５）please comment : shoji@kaiyodai.ac.jp

Thank you for your kind attention