naval architecture exercise

[save]

Hi!!
I'm searching for some exercises related to screw design..
I'm talking about Wgeningen B series, screw strength with Taylor, cavitation analysis with Burrill..
I have theorical dubts related to these problems, so I would like to see some correct examples..
Anyone could help me?

Thanks a lot!!

[jehardiman]

No one looks into propeller design as an exercise; there are too many variables in it to make a good basic learning experience.

What is the problem you are having: theory or application? And approaching the propeller design from what perspective: initial design? FWIW, the three things you named are only tenuously related. Wageningen B design is based on a standard series data (1948) look up chart, Taylor blade beam analysis (1910) doesn't apply to standard series, the same with Burrill's cavitation (1943) and stressing (1959). I suggest that you go read Chapter 6 of Resistance and Propulsion of Ships (SV. AA. Harvald, Wiley & Sons, 1983, ISBN 0-471-06353-3) with particular attention to 6.6 Cavitation and 6.7 Propeller Design Theories.

[Adler]

See also that if you can follow the maths' level that applied.

"Marine Propellers and Propulsion" J S Carlton Senior Principal Surveyor
Technical Investigation ,Propulsion
and Environmental Engineering Department of Lloyd's Register
First Published 1994

Butterworth and Heinemann Ltd
Linacre House , Jordan Hill , OXFORD OX2 8DP

ISBN 0 7506 11 43 X
British Library Cataloguing in Publication Data.

[save]

Thanks.. This is my first problem:

Given:

- L,B,T,displacement,Cx, S
- effective power curve for different ship velocities
- shaft horsepower
- shaft efficiency
- wake fraction w
- thrust deduction fraction t
- relative rotative efficiency

Choose:

Best 4 blade propeller from B series chart that give the maximum service velocity

[save]

i also know the RPM

[Adler]

Please see the attached files.
Prof. Sverre Steen NTNU had developed a .xls file for Propellers Calculations (90136.xls) and a .doc file for instructions (90137.doc).
I think that is near of what you asked .....

If you need to try on this .xls file you have to contact him at:
http://folk.ntnu.no/sverres/

[save]

is not what i was searching for but thanks a lot

[jehardiman]

Originally Posted by save

Thanks.. This is my first problem:

Given:

- L,B,T,displacement,Cx, S
- effective power curve for different ship velocities
- shaft horsepower
- shaft efficiency
- wake fraction w
- thrust deduction fraction t
- relative rotative efficiency

Choose:

Best 4 blade propeller from B series chart that give the maximum service velocity

Originally Posted by save

i also know the RPM

You specificaly need to read Principles of Naval Architecture (1988 ed), Volume II, Chapter 6, Section 8.3 (pgs 186-204) as this appears to be a problem lifted straight from the text.

[conceptia]

yes.. PNA Volume 2 will serve the cause.

[kerrett]

hi save I send you something via mail..

[kerrett]

Are you studying in Italy?