Sail efficiency = speed gained ?

Sails do different jobs with different relative wind directions. Using a fore-and-aft sail to go to windward relies on aerofoil effects you seem to be enchancing with your ideas of improved efficiency. But crack off onto a broad reach or a run, and total sail area is much more important than perfect foil shape.
On this count, reducing sail area 5% would reduce speed somewhat on any point of sail other than hard on the wind, and only if your idea works as claimed.
Not all sailing is as upwind as possible, though some without sea time would seem to think so.

 

You are missing the definition of efficiency. Is this driveforce/sideforce, reduced weight, better sail handling? better sail setting after tacks/gybes? better control through manouvres? Are the improvements upwind, downwind or offwind?

You are also missing the understanding of how the forces balance on a yacht and how drag of the hull and appendages can be calculated based on empirical formulae. Hence if you have improved the D/S ratio, does that mean you get more drive, or less sideforce? This will make a big difference for the change in speed.

Incidentally, I wouldn't describe myself as an expert in any field, but certainly professional in one or two, and educated in the field of Naval Architecture with emphasis on yacht design. So I like to think I know what I'm talking about.

You pose a very hypothetical question which to most of us sounds like you want a one-liner from a Naval Arch. You're unlikely to get one. I think you need to do some basic research into fluid dynamic lift and drag and performance prediction before you proceed, otherwise how will you be able to make sense of your findings?

Tim B.

 

hprasmus get yourself some unbiased patent advice, read "Nolo Patent it yourself"

Chances are you can make money from your idea without a patent! That's what you should be thinking of; read boutique co. making product, while the big guys could not be bothered about your few 10,000s in sales. If it does not get banned in racing rules.

NO CO. WILL PAY YOU FOR YOUR IDEA. They will modify or simply ignore your patent and put the onus on you to enforce it.

 

Boat speed is not linear. What you can increase is VMG, and there are many factors that go into if you can sail at a higher angle.

 

Reminds me to exercise some polars
Not so easy to calculate as fe stability or velocityu tho

 

The simulation was conducted in apparent wind angles of 28 to 40 degrees. In that register the performance incresed with the angle of attack. However there should be no loss of efficiency at more off wind courses. The benefits may decrease or be neutral, but no net loss of efficiency should appear.

 

Present the data.

Tim B.

 

Bataan, also remember someone mentionin

lots of wisdom, still, engines change and horses for courses and that
than again allyou old salts have that sayimg engraved in your winches


Typed from mobile, srry for my big , was gonna say thu
ps... Sails? Whoooooha0ops

 

The general wisdom is that Beecher Moore fitted "bell ropes" to his Thames A Rater, as you say, and that was developed in International 14s by Charles Currey, Sir Peter Scott and others.

Kiwis say that they were used in an M Class a couple of years earlier (1937 off the top of my head).

However, the use of trapezes, complete with belts, was described by two independent writers decades earlier, with up to eight traps being used in Asian racing canoes. Interestingly, the one academic I could find who was studying craft from that area didn't know about the traps. However, the two articles could hardly be clearer about their design and use and they were definitely traps.

One description is in a 1906 book, another in a US or UK mag about 1920. A patent office search would, as I understand it, pick up neither of these clear examples of prior art. Obviously no one is going to try to patent the trap, but it's a classic example of the difficulty of saying that one was first.

 

Just the sail is smaller and has less drive on 280 degrees of possible and desirable courses. Less AOA means your performance advantage goes in the bucket after 40 degrees and you just have a smaller sail and less driving force.
Some imagined racing advantage but forget it in the real world.

 

Trapeze probably invented before 1937.

 

Great pic, Bataan.

It's certainly not a trapeze, of course. The trapezes that were very well documented in the same geographical region well before 1937 were the same as modern traps, with a line from the mast and a belt around a sailor who stood out horizontally with his feet on the gunwale.

Your pic does seem to indicate that western racers (who seem to have invented the modern rack in the '60s in Moths) were not the first to have that idea, which really underlines how hard it is to find all the prior art relevant to a sailing patent.

 

Modern sailors have had few original ideas.

 

Actually, it can be demonstrated that squared inches are more important than cubed ones even for cars.

 

sure, but that quote stuck somewhere in memory