Originally Posted by Chris Pap
Thank you for your interest and your quick reply.
Unfortunatelly i am trying to optimise a swath so ulimich cannot help me right now(although i will download it, these things are always usefull).
I looking forward to run Flotilla then in the next weeks.
Thank you again, and congatulations about michlet.
I strongly suggest that you look at this thread: SWATH resistance predictions using Michlet
As you will see, SWATH require some special treatment vis-à-vis form drag.
In general, you do not need to use any form factors for most thin hulls,
(1) SWATH usually have a rounded nose (which violates the thin-ship
(2) It is best to use two form factors: one for the strut and another for the
torpedo-like lower portion.
These dual form factors are a rough-as-guts way of accounting for (1) and
possible separation at the intersection of the strut and bulb.
The 1st post in the thread also contains a short report that compares
Michlet predictions with towing tests of a model SWATH. The strut and bulb
are comprised of mathematical shapes, so you should be able to create the
offsets yourself. One way is to use Michlet's mathematical hull series and
combine them into a SWATH strut-bulb combination. It's a bit messy, but
it will actually give very accurate (4 or 5 figure) accuracy for the shapes.