How to deal with truncated transome?
› DELFTship forum › Hydrostatics and stability › How to deal with truncated transome?
 This topic has 2 replies, 3 voices, and was last updated 10 years, 1 month ago by Becker.

AuthorPosts


July 1, 2012 at 23:55 #36086
I have a question about truncated waterlines. In computing Cp, can one use imaginary extension of waterlines of the healed hull in order to compute true value of Cp? The picture should explain my question. I do understand that there is a discrepancy in this, but what is more wrong:
(a) compute Cp with truncated waterline (and get distorted hull’s shape Cp) or
(b) compute Cp with imaginary waterlines (and get an hydraulics error and get more proper shape for computational purposes)?Thank you all for your help.

July 2, 2012 at 18:11 #36089Eric BaileyParticipant
I don’ know if my experience covers this situation but – wouldn’t using imaginary waterlines where the hull is not – give you imaginary coefficients?
I take it upright the hull DWL ends just before the hull does? Is there a reason not to extend the hull? You would get a little better flow I would think…
Also, I wonder if the heeled coefficient thing is a new fangled idea coming from designing in a computer? I never bothered with it back when I designed a couple power boats manually… of course they were power boats…
I am really curious to see what others think of this – good luck.
Eric

July 5, 2012 at 13:39 #36092BeckerParticipant
Hi all,
it is a interesting question.
In my opinion it is not really a problem wich length and Displacement you use for prism. coeff.
Think about the question: How do you use these coefficients.Most time you just want to compare quite similar hulls.
On the other hand, with your vitual hull, you get a bigger length and a bigger Displacement. Mainframe section keep quite the same cp will not vary very much.
A quite similar discussion is about Froude numbers. Wich length do you take for froude number….
For comparing similar hulls, it is only important that you always take the same length.Greetings, William


AuthorPosts
 You must be logged in to reply to this topic.
Your account
Recent Topics

Download Problems
by William Boebert
1 week ago

Developable surface (wrong orientation)
by Hrvoje
1 month ago

Modelling a flat bottom chine tug hull (WWII TID)
by Paul
1 month ago

Need OSV, AHTS,PSV Vessel hull bodylines plans
by jacksparrow1912
1 month, 1 week ago

Can’t figure out how to model the back
by Tidexon
1 month, 2 weeks ago

Critical Program Error
by Allan Russell
1 month, 2 weeks ago

Saving reports in Word or Excel format
by Berislav Tusek
1 month, 4 weeks ago

Attaching keel to hull
by Matthieu
2 months ago

Modeling the 1907 U.S. Brigantine Galilee
by Terrance Egolf
2 months ago

HOW TO USE THAT SOFTWARE
by mirmir
3 months, 4 weeks ago