single surface sail with round mast
single surface sail with round mast
(OP)
I would appreciate any references which have at least some coverage of single surface sails using round mast (such as a windsurfing sail). Im specifically looking for references which deal with the seperated flow in the area behind the mast.
Thanks in advance,
Wally Hall
Thanks in advance,
Wally Hall





RE: single surface sail with round mast
1. In the typicall operating range (described below), would this both result in less seperated flow and hence lower drag without affecting lift much (ie, an improvement in L/D?). Is the rope sewn in a zig zag manner going to create the desired effect or just add more overall drag?
2. How large a structure is needed (rope diameter, distance from bend to bend) and where would it optimally be placed?
Some specifics about the application: Sail width is about 2 meter, height is about 5 meter. Round Mast diameter is approx 4 to 5 cm and the mast is inside of a sleeve which is part of the sail. The sleeve width is typcially about 10 to 15 cm - sometimes even more. Speeds are typcially 20 to 35 mph for a windsurfer and up to 60 to 70 mph when used on an ice or dirt boat.
Thanks,
Wally Hall
RE: single surface sail with round mast
Roughening the surface of the wing in the nose area helps prevent separation further back at high AoA, I don't think (I'm guessing) it really has much effect where you still have laminar flow.
Cheers
Greg Locock