CFD with free surface effects and a 6-dof model could be considered as a good solution? "This Munk moment arises for a simple reason, the...
Wow - that was fast. Attached pics of a sample run of the Dehler 33 in a state of the art CFD program XFlow: . [ATTACH][ATTACH] XFlow is showing...
A truly impressive job Uli, UliSpeed is indeed in the masterclass among VPPs. From the manual I read the UliSpeed cover "5-DOF", or 5 degrees of...
Thanks for the link to wayback engine - it appears one can find there our old site, too - sometimes asked for its aero-pages and Sailpowercalc in...
The diagram is theoretical, from a VPP for a generic AC75 which corresponds fairly nicely to measured sailing data. I don't think you could gain...
If you look at the AC 75 drag breakdown attached, you will see that there is not much to be gained in the hull air drag. Foils are most important,...
Modeling Star in UliSail: results compare nicely with a VPP run of Star, with sailcoefficients based on CFD, despite the Star sailplan being quite...
Erwan, no secrets here - I normally use k= 0.12, or between 0.1 to 0.14. The law itself is Windspeed * (H/10)^k. 0.6 would be an extremely stable...
Reading the manual often helps: You refer the BETATW to the boat axis, while I have my TWA referred to the direction of motion? So 40 deg in...
Also, I’m not using the log law for wind shear, but the power law, hence your coefficient 0.02 would not be correct for me.
I noticed a typo in my wind shear numbers, will rerun your test case when I get back in Office.
OK. So do I in my VPP, but the general approach (like ORC) tends to be to define it relative to the direction of the motion, so they (ORC) think...
OK, I will take a look at it. The genoa is actually OK, it was the mainsail with convex camber that would be difficult. You are right, it's the...
OK, will do, I can use the IGS directly, I don't have Rhino. These are very flat.. they would not be realizable from sailcloth, due to the convex...
Thank you Uli for posting Ulisail. I devised a simple template to easily visualise results. Mainsail values are in black, headsail in red. If I...
