# Planing Condition

Discussion in 'Software' started by bulgafabio, May 10, 2008.

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### bulgafabioNew Member

I'm making a thesis work on VPP. We have an experimental sailing yacht (skiff type,4.6 meters long) and we have lot of troubles in calculating the total resistance of the hull because it's of planing type. The problems are:
-don't have a theoretical model to compute the resistance for planing,only for displacement
-dedicated software we found cost so much and we cannot afford buying them
In this way our VPP is unusable an so we cannot make the optimization we would do.

2. ### Guest625101138Previous Member

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### bulgafabioNew Member

Still some problems

-the graph starts from 15 Kn and for our boat is practically the maximum speed.
-where can I find Savitsky's paper about hydrodynamic design of planning hulls?

4. ### Guest625101138Previous Member

Search this site. Savitsky is referenced quite often showing a pdf of the paper and there is a spreadsheet for it as well.

It is not the easiest theory to apply.

For practical size boats, the 15 kts is as low as they can go before they move into a transition mode. There is also lengthy discussion on semi-displacement on this site.

Rick W.

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resistance under planing conditions

try to look at the paper I post time ago on this forum http://www.boatdesign.net/forums/showthread.php?t=20495 ( Planing Hull 1-Master.PDF) see if it helps.....savitsky's computational procedure is clearly explained plus the equations used which are explained/enclosed.....
the procedure is clear enough and results could be helpful.....

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quasi ok: