Where is the limit of rationality?

Kus on mõstlikkuse piir?

18/04/23 1SI:KI:PING Prof Anatoli Alop

1. Speed is above all!(??)Or speed as an end in itself?Affected by three main faktors:

18/04/23 2SI:KI:PING Prof Anatoli Alop

R

v

T

Power Efficiency

Resistance

Source:http://images.gougle.com

Source: H. Punab, Laeva jõuseadmed. Tallinn, 2008

Source:http://images.gougle.com

The ways for speed increasing

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1. More power ?

SHIP PROPULSION PERFORMANCESource:http://images.gougle.com

The ways for speed increasing

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The better propulsive coefficient?

MPP

p

e

s

e vT

Source:http://images.gougle.com

The ways for speed increasing

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Ship propulsion devicesA. Active devices

Sail Flettner Rotor

Source:http://images.gougle.com

The ways for speed increasing

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B. Re-active devices I

Oars Paddle-wheel η < 0,5

Voith-Schneider propeller, η < 0,5 (for speed more than 20 knots)

Source:http://images.gougle.com

The ways for speed increasing

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Source: http://en.wikipedia.org/wiki/Propeller

Ship propeller from 1843 Propeller on a modern mid-sized merchant vessel

B. Re-active devices II

η = 0,7 ... 0,75

The ways for speed increasing

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B. Re-active devices II

Water-jet-propulsion system Source:http://images.gougle.com

The ways for speed increasing

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Perfection of propellers

Source:http://images.gougle.com

Examples

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http://www.youtube.com/watch?v=qgSfrqAYopg

http://www.youtube.com/watch?v=RI9zRXmowO8&feature=related

http://www.youtube.com/watch?v=2pQga7jxAyc

http://www.youtube.com/watch?v=VuobfwRo-IE

http://www.youtube.com/watch?v=FJzK_S5ipc4

http://www.youtube.com/watch?v=meDcNK0-tio

http://www.youtube.com/watch?v=GZaPmnJKC0A

http://www.youtube.com/watch?v=0hWdvw1TTZg

http://www.youtube.com/watch?v=qg14dKSByM8

The ways for speed increasing

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Perfection of propulsion systems

Source:http://images.gougle.com

Cavitation

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http://www.youtube.com/watch?v=GpklBS3s7iU

Source:http://images.gougle.com

The ways for speed increasing

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Decreasing of fluid resistance?The main types of resistance:1.Friction resistance2.Form resistance

1 – vaba voolu ala2 – piirikiht3 – hüdrodünaamiline jälg (kiiluvesi)

2

2

3va

a

1

Source: H. Punab, Laeva jõuseadmed. Tallinn, 2008

The ways for speed increasing

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vmax

vmin

v

vmin

p+

-0

The main types of resistance:3. Wave making resistance

Source: H. Punab, Laeva jõuseadmed. Tallinn, 2008

The ways for speed increasing

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The main types of resistance:3. Wave making resistance

Lahknevad lained

Põiklained

Vöörilainete süsteem

Joon. 2.6

Ahtrilainete süsteem

Body in fluid

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Examples

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http://www.youtube.com/watch?v=5fQkhTl0LYA