Michlet multihulls - drag on individual hulls?

Hi,

When doing multihull analysis, can you see the drag resistance on each hull including the interference effects?

I am wanting to see how much drag on each boat for various kayak fleet formations.

Regards,
Tom

 

Yes you can.

 

The Resistance menu seems to show individual hull resistance WITHOUT interference, or collective resistance WITH interference.

How do I show individual hull resistance with interference?

 

Sorry, I misunderstood your first question.
You can't show the individual hulls with interference.

 

Thanks for your replies.

Do you know any software that might do this, or somewhere I might research it?

See, my club is trying to figure out whether wake riding penalizes the lead boat, and if so how much. We have lot of opinions, but not much solid data!

Regards,
Tom

 

That depends on the distance between the two hulls, but in general the
lead boat won't suffer much of a penalty.

The top figure of those on the page
http://www.cyberiad.net/waketandem.htm
shows that the boat at the back gains an advantage when the separation
is 1.5 wavelengths. It also gains if the separation is 2.5, 3.5, ...
wavelengths. Clearly, the further back it is, the lower the influence
it can have on the lead boat.

When the boats are close together, the "near-field" effects also
interact, so the lead boat can be influenced by the boat behind (or to
the side of it). See, for example,
http://www.cyberiad.net/wakeweinblum.htm

The pressure field around the boat behind can, for example, induce a
small amount of trim on the lead boat, which could be beneficial or
detrimental. Again, the distance between the boats is important.

I have programs that can determine the effects, but I am in the middle
of other work at the moment. If you know someone who can run OpenFoam
or other free CFD codes you might get some good quantitative results.

Good luck!