Hi Everyone, I made some changes to my channel this winter that resulted in YT deleting all of my comments/replies on these videos. It's really a shame, because I feel like I have answered quite a few theory questions in the comments section over the years. If you have a question, even if it looks like it's been asked before, please don't hesitate to post a comment, I'll do my best to get back to you. Cheers, JH
I wish you calculated the apparent wind velocity for each point of sail. Would also love to know how to figure out the actual speed the boat is going on each point of sail with these numbers.
Nice presentation. New to sailing aerodynamics, so I have to rethink this in aviation terminology (i.e. geometry). Here goes, help me out if I'm off the mark. For a close reach (say 30 degrees off), the apparent wind vector is treated as a "crosswind" from the bow of the boat. 30 degree wind vector is .5 of the true wind velocity. (Sine of 30 degrees = .5) So apparent wind hitting the sail is 7.5kts. So your sails feel a 7.5 kt wind. A broad reach, (say 45 degrees) is now .7 (Sine of 45 degrees = .7) Now the sails feel 10.5 kts of wind. A beam reach, (90 degrees) feel the full crosswind of 15 kts. (Sine 90 degrees = 1.0) So a in a beam reach your sails feel the most wind. I don't believe you can figure out boat speed using this equation because each boat has a different drag qualities. Some have keels, some dagger boards some use water ballast. Lift from the sails have to overcome drag for that particular boat's design.
Hi Everyone,
I made some changes to my channel this winter that resulted in YT deleting all of my comments/replies on these videos. It's really a shame, because I feel like I have answered quite a few theory questions in the comments section over the years. If you have a question, even if it looks like it's been asked before, please don't hesitate to post a comment, I'll do my best to get back to you.
Cheers,
JH
You are a national treasure sir.
Excellent and simple to understand, thank you
Thanks for your valuable help.
It would be nice if you could give an example an explain how it is possible to sail DASTER than the True Wind
Really clear. Thank you.
Wow, that's teaching! Tks
I wish you calculated the apparent wind velocity for each point of sail. Would also love to know how to figure out the actual speed the boat is going on each point of sail with these numbers.
Excellent well-paced presentation Sir Julian.
Thank you for this :)
Nice presentation. New to sailing aerodynamics, so I have to rethink this in aviation terminology (i.e. geometry). Here goes, help me out if I'm off the mark. For a close reach (say 30 degrees off), the apparent wind vector is treated as a "crosswind" from the bow of the boat. 30 degree wind vector is .5 of the true wind velocity. (Sine of 30 degrees = .5) So apparent wind hitting the sail is 7.5kts. So your sails feel a 7.5 kt wind. A broad reach, (say 45 degrees) is now .7 (Sine of 45 degrees = .7) Now the sails feel 10.5 kts of wind. A beam reach, (90 degrees) feel the full crosswind of 15 kts. (Sine 90 degrees = 1.0) So a in a beam reach your sails feel the most wind. I don't believe you can figure out boat speed using this equation because each boat has a different drag qualities. Some have keels, some dagger boards some use water ballast. Lift from the sails have to overcome drag for that particular boat's design.
Sorry, meant to say "close haul" and "close reach" instead of close reach and broad reach, still learning here...........
excellent video.. too bad you stopped making them! thumbs up!
10 min start vectors
Beam reach 13 min
Why in the world would you use km/hr instead of knots ? Just showing off how european you are ? Sailors use knots and nautical miles.