21
1 Estimation of Ship Resistance School of Internet Program 06.01.2009 Estimation of Ship Resistance from model Experiment Faculty of Marine Technology Tokyo Faculty of Marine Technology Tokyo University of Marine Science and Technology Shoji Kuniaki Kuniaki Shoji Department 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 Tokyo Doctoral 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

Estimation of Ship Resistance of Ship Resistance from ... · 3 Wave making resistance Resistance Test by model It is difficult to estimate ship resistance by only theoretical calculationby

Embed Size (px)

Citation preview

1

Estimation of Ship Resistance

School of Internet Program 06.01.2009

Estimation of Ship Resistance from model Experiment

Faculty of Marine Technology TokyoFaculty of Marine Technology Tokyo 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 Tokyo

Doctoral 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

2

Outline of this Lecture

• In this lecture Froude’s method is explained. This is a estimation method which evaluate s s a est at o et od w c eva uateactual 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

i i i d d A h lresistance test is introduced. As these results, estimation method of actual ship resistance so called Froude’s method is explained.

Components of Ship Resistance• Total Resistance = Water Resistance + Air Resistance• Water Resistance = Frictional Resistance + EddyWater Resistance Frictional Resistance + Eddy

Resistance + Wave Making Resistance• Water Resistance = Frictional Resistance + Residuary

Resistance• Water Resistance = Viscous Resistance + Wave Making

ResistanceResistance• Residuary Resistance = Eddy Resistance + Wave Making

Resistance• Viscous Resistance = Frictional Resistance + Eddy

Making Resistance

3

Wave making resistance

Resistance Test by model

It is difficult to estimate ship resistance by only theoretical calculationby only theoretical calculation.

Then it is experimented now at the experimental tank, so called SHIP MODEL BASIN, SHIP TOWING TANK .

4

William Froude• 1810年~1879年

• Who Called the Father of Modern NavalWho Called the Father of Modern Naval Architecture

• From Experience to theory • Estimation of Actual Ship Resistance from

Model Experiment(Froudes’ Method)Model Experiment(Froudes Method)

• Froude Number Fn=V/(gL)1/2

• Method of Model Experiment• Construction of Towing Tank

Towing Tank

• Towing Tank of Yokohama National• Towing Tank of Yokohama National University(Japan)

• Berlin Model Basin(Germany)

• Which facilities are there?• How experiment there?

5

Experimental Tank of Yokohama National University

Yokohama University Ship Model Basin

6

Profile of Yokohama University Ship Model Basin

Dimensions of Yokohama University Ship model Basin

7

Towing Carriage

Self Propulsion Test

8

Control Room and Resistance Dynamometer

Resistance Dynamometer

Resistance DynamometerBalance

measurement

id

Trim measurementTrim measurement

Towing Carriagey

Ship model

guide

Towing Rod

Counter Weight

guide

9

Shaping Machine

Berlin Model Basin

10

BerlinModel Basin

Berlin Model Basin

11

推進試験、係留試験

Flow Measurement of Aft Body

12

Towing Tank

Towing Tank(Wave Maker Side)

13

Towing Carriage

Towing Tank

14

Trimming Tank Side

Casting Box

15

shaping machine

Circulating Water Tank (the biggest in the world)

16

Circulating Water Tank

William Froude(1810-1879)

17

Towing Tank at Torquay

Towing TankYokohama Tokyo Berlin TorquayNational University Model TowingUniversity 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

18

Experiment of Actual Ship

Experiment of Greyhound

E i f Pl k ShiExperiment of Plank Ship

Experiment of Yudachi

Evaluation of Actual Ship• Training Ship of Faculty of Marine technology

「SHIOJI MARU Ⅲ」

• Length:Ship=46m Model=1 5m• Length:Ship=46m、 Model=1.5m• Scale 1/30.6• Model Measurement V=1.0m/s ⇒RTM=0.2kg• Resistance of Ship RTS

0 2k ×30=6k ?0.2kg×30=6kg ?

0.2kg×302=180kg ?

0.2kg×303=5400kg=5.4t ?

Speed of Actual Ship =1.0m/s ?

19

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.)

• Resid ar resistance of ship and model is• Residuary resistance of ship and model is proportional 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 maru Ⅲ

• Corresponding speed:model 1.0m/sship 1 0m/s×301/2=5 5m/sship 1.0m/s×30 5.5m/s

• Frictional Resistance:from resistance of platemodel 0.1kgship 1.5t

• Resistance test :water resistance 0.2kgg• 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

20

Water resistance of shipResistance coefficient

model

ship

Reynolds number

Evaluation of Ship Resistance

Ship resistance

Estimation 1

Estimation 2

21

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 : [email protected]

Thank you for your kind attention