foils can only be designed to work over a narrow speed range. for steady flight lift must equal weight. so as you go faster you must reduce lift! this is done by pitching down... the foil that got you out of the water at take off speed is now too big and limiting the top speed. My understanding (from ray vallenga diy foil book) is that foiler top speed limit is usually only about double take off speed. on the other hand, planing naturally reduces lift by just lifting out of the water and touching it less. so it can go faster, but with a bumpier ride
1 year ago | 1
@joeordinary2trumpheroofrussia
At lower speeds the drag of the foil is less, but at a certain(very high) speed the foil will induce more drag then the planning hull
1 year ago | 0
foils mitigate pressure drag, but have more surface area for skin drag to develop. to negate cavitation, you have to reduce wing loading, which means using a bigger foil, but that also makes more skin friction. planing can give you the same lift using a smaller area, so less skin friction, though with greater pressure drag. at some point as speed increases, that balance flips, and you just want to minimize area to reduce skin friction. same reason as to why modern high speed jets aren't long and slender like commercial aircraft.
1 year ago | 0
Mark Palmquist
Which can attain higher top speeds in high winds?
1 year ago | [YT] | 1