What is the effect of aerating a planning boats on it's performance

intrepid71 - Since a hull must support it's weight with Lift, when available lift is reduced (due to lower ρ, say) then the hull must have more wetted surface (at less efficient lift) to compensate - since the total Lift must still = total Weight. So the added sf generates more Total Drag and L/D is reduced.

I'd still be interested to read your paper. If you have an idea of what I would search for at Webb Inst. library, send to me in PM or email. thanks.

 

Only true if S * CD does not increase faster than ρ decreases with the air present.

 

There was some research I have read about snow skis "floating" on air. As it moves, it melts the snow because of the heat generated and the ski is supported by air.

Same thing with sking on ice. The blade is not sharp but the heat developed melts the ice forming a "lubricant" between the ice and the blade.

Of course, melting is not instantenous so it must be occuring AFTER the tip or forward portion meets the ice/snow.

Maybe the sharkskin has some merits after all. Notice the turbolators and the strakes which keeps the turbulent water aligned. In my understanding, anything that will break the cohesive properties of water will provide lubrication. Just maybe not that much.

 

There's a section/information on this in Steve Dashew's Book "Offshore Cruising Encyclopedia-II". It covers reducing drag a lot, via this method, in a large monohull. But I don't have the book on hand at the moment. You might query him, as well as dig into the book. The website's www.SetSail.com Perhaps with a little digging, you could find a copy of his book online in PDF format (if so, please drop me a line).
Ah, & I'm going on a swiss cheese memory here, but such an aireation system may be on one of Lars Bergstrom's boats.

Also, I have no idea if they've got info on it, but the AYRS (Amateur Yacht Research Society) has done interesting studies into all kinds of "fring'ish" ideas, and come up with some damn good ideas & data. It's worth a look.

PS: I think that this idea has also been tried on some of the large, single-handed, racing boats. And it's an educated guess, but such a setup is likely only worth the effort at certain hull speeds, & with certain hull forms. As, to the best of my knowledge, it's not in use on many current vessels. Though that may be due to rating "rules", read heavy penalties for it's use. Much like Catamarans were "outlawed" after Herrshoff made a mockery of a regatta or two with his, a century back.