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PostPosted: Fri Jun 14, 2013 9:15 am 
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Sounds very interesting Bob!

I think the term you were looking for for the interaction of the jib and the mainsail is the "slot". I think you have some of your explanation round the wrong way too, as the side of the mainsail which gets blown in when the slot is too tight is the leeward side, ie the back. In addition the ama that is buried to 1/3rd is the leeward (low) one.

Keep up with the R & D, I find it fascinating. Round here, I normally get enough wind, and tend to go for a pedal and use my TI as a fishing platform when the wind is not there, but I appreciate that you get different weather patterns where you are.

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PostPosted: Fri Jun 14, 2013 10:53 am 
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Glad to hear the test worked out and met most of your expectations Bob. How well did it perform in a downwind situation? The design is quite cool. And it seems it could be easily modified to fit an AI too.

That effect you mentioned of the airflow over the jib disrupting the mainsail wind is something that I've suspected in my setup for awhile now. Sometimes I experience better performance and sometimes worse with my jib setup. Wish I had a wing sail ....

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PostPosted: Fri Jun 14, 2013 12:17 pm 
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CaptnChaos :
I never tried a direct downwind, but from what I understand wing sails are pretty useless direct downwind , basically just the wind pushing against the flat side of the sail (no lift, an umbrella would likely do better LOL), but I did get a chance to sail with the wind coming from around 150 to 160 degrees, and it actually performed fairly well (better than just a mainsail). Looked a little strange pointing backwards though. As you know the mainsail by the time you get to that angle downwind is really loose anyway and the performance on a TI really drops off on downwind (that's why I added the big spinnaker in the first place). Actually it was then that a big boat went by and the waves rocked me back and forth quite a bit, the clip I had on the bottom of the wing sail came unhooked, and the sail was waving around away from the boat like a kite, the only thing holding it was the top, and a loose furling line. Probably looked comical me chasing it trying to catch it (glad nobody got that on video).

Bob


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PostPosted: Sun Jun 16, 2013 4:46 pm 
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I have great news, my wing jib is a flying success (get it it's a wing LOL), and works way beyond even what imagined.
Here is a screen dump from my Iphone showing what the wind was like at around 1:00 in Sarasota:
Image
I said in the video they were forecast for 9 mph, I don't think it ever got that high while I was out.

Just to show that the jib is an actual wing here is a pic of the jib laying on the garage floor, it's about 4 inches thick at the wide points (typically about 15% from the leading edge. (note to self, get rid of that stupid foam I glued on the inside to try to keep the sail surface more uniform, it didn't work)
Image

Here is the jib all furled up on the floor:
Image

Here is a video sailing with just the jib, the wind according to Weather.com was only around 7 mph at the time, the fastest I got was around 5mph with just the jib:
[youtube]http://www.youtube.com/watch?v=ETwxZZMtyxg&feature=youtu.be[/youtube]

Now here is the jib working with the mainsail (it's intended purpose), notice the depth of the leeward AMA, the jib doesn't apply any additional heeling moment to the hull, and by all appearances doesn't appear to add any additional stress to the mast or hull either from everything I can see (way contrary to my old non wing jib (the same size), that really stressed the mast and hull of the boat.
I had to quit the video quickly because I was about to run into a bridge.
[youtube]http://www.youtube.com/watch?v=A13bnkQ_saY&feature=youtu.be[/youtube]

Here is another one where I got up over 7 mph, best all day was over 8mph a few times.
[youtube]http://www.youtube.com/watch?v=8hgdFu9xuQI&feature=youtu.be[/youtube]

The most amazing performance was upwind where I was pointing around 20 degrees from the wind and got up to around 7 mph upwind (in 7-8 mph winds)
, this is better than anything I have achieved before with all my sail designs on my TI's. Upwind performance has always been lacking for me with all my previous designs, this beats everything else I've tried hands down, plus it put's no additional stress on the boat itself, which is a bonus that I didn't realize until I actually used it. Also when in the neutral position it doesn't appear to add much wind resistance if any, it just free wheels and the wind goes around smoothly.

Now the downside, when I furled the sail when coming into harbor, it ended up a little looser and bigger than planned, it's probably much less wind resistance to just leave it deployed and in neutral (lesson learned). But it only took a few seconds to furl it and drop the halyard at the end of the sailing day. That's what I do is I leave the jib and the spinnaker attached to the bow with all the control lines hooked up. When I launch or go home both the sails just lay on top of the boat on the trailer and in the garage (I never remove them). Of course I still have to step the main mast and strap it down to the hull, but that's pretty easy and fast.
Here is a quick video of the jib furled on the water, nothing fancy, just pulled on the furling line and wound it up with the furler (took maybe 5 seconds)
[youtube]http://www.youtube.com/watch?v=buWkPhcRuOQ&feature=youtu.be[/youtube]

Now here is a video of my screacher prototype (converting sail from a G2 spinnaker to a wing screacher (still in design), which hopefully will amplify the wind (currently the G2 spinnaker cannot amplify wind, it basically goes 1=1 downwind only)


[youtube]http://www.youtube.com/watch?v=XRQdfhZXCVk&feature=youtu.be[/youtube]


This has been a really fun project, took way too long (over a year to design, and over a month to construct, but I think I will have years of service from these sails ( I try to design and build them to last about 3 yrs of heavy use typically). That spinnaker in the last video is over 3 yrs old with 2500 sailing miles (of course not in the air all that time, but it's always on the boat ready to use.), and it's pretty worn, so I am probably looking at a totally new sail and design for the new wing screacher (hope it doesn't take me another year to design).

The wing jib is officially completed, I'm just planning to just use it for the next few years, we are going down to Key West for the month, and I'll be sure to take it along.

Project done finally
Bob


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PostPosted: Sun Jun 16, 2013 7:23 pm 
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Nice job once again Bob. The tests look great and thanks for posting the videos. I need to take some sewing lessons :lol:
Jim

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PostPosted: Sat Jun 22, 2013 1:34 pm 
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Like I said in the last video my plan was to modify my existing spinnaker by adding a wing shape just to the leading edge to try and get better performance in light winds on a reach with the spinnaker. The old spinnaker design was downwind only very loose parachute type spinnaker that captures light air on downwind and helps propel the TI downwind better than just the mainsail (downwind is kind of a weak point on TI's, that why I added the spinnaker in the first place).
Here is a quick video of the spinnaker in action, sorry I couldn't get around to the front of the sail to see the wing foils all puffed out with air.
[youtube]http://www.youtube.com/watch?v=p1ACrUXgp0E&feature=youtu.be[/youtube]

Basically I'm done with the sails for a while, with the new wing jib the boat literally screams upwind. The jib works perfectly on pretty much all points, and is super simple to operate, pretty much everything is totally automatic. I even have a setup where I can use the jib as a kayak sail in kayak mode. I have tried sailing my TI in kayak mode with the mainsail, but even with the sail furled, the boat tips over too easily. With this wing jib there is no side force so it should work very well as a kayak mode sail (with no AMA's).

I didn't want to lose my spinnaker, but in light winds it was only good for downwind, now with the wing on it, I can also use it in a light wind reach, and maybe a little higher than 90 degrees.
Bob


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PostPosted: Tue Jun 25, 2013 4:36 am 
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Hey Bob,
When you tried to explain to me what you were trying to do with the Spinnaker and a wing I guess I just couldn't comprehend what you meant... this video is very enlightening... now I (think I) get it!
This is pretty big if I understand the results properly... it sounds as though, by putting a short piece of a wing on the Leading edge only of the Spinnaker, you have greatly alleviated the difficult issue of getting a Spinnaker to fly in a useful manner and can "easily" now get the Spinnaker to be useful on other points of sail other than directly down wind!
Pretty impressive!
With the previously dayviewed jibwingsail, it is going to be interesting to see you sail along side standard AI/TIs... I'm betting not for very long!
I'm looking forward to seeing you in action... soon I hope.

Don

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PostPosted: Tue Jun 25, 2013 9:14 am 
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Don:
Around here (Sarasota bay) the winds are more often than not only about 5 mph. It's actually nice to go out in calm because the water is very flat with no big waves. Unfortunately when I first got my TI I found it very boring going out in such low winds. Basically the stock boat goes about .6 of the windspeed on average. So in 5mph winds I think I can swim faster. One of the nicest features of the TI's is the mirage drives, if there is little to no wind you can always pedal everywhere (I tend to do that most of the time around here).

This video shows me on a typical day out in this area, with the typical winds (<5mph).


Now this video was taken on the same day using my motor (powersailing) : (note: at around .30 into the video you can see the bow flexing up and down about 2 inches in the waves)


Using the motor to generate some apparent wind I was able to get up to around 7 mph in no wind conditions. The motor uses very little fuel, it goes around 50 miles on one gallon of gas.
The small 22 ft jib in the video was all that was left of my old 35 sq ft original jib sail which had totally worn out and had to be cut down, so I had to make a new jib anyway. 22 sq ft is actually a little too small for the TI (probably perfect for the AI though).
Now with my new wing jib I am hoping to be able to motor sail at around 8-9 mph in virtually no wind (wishful thinking (yet to be tested...)) by creating my own apparent wind . The increase in efficiency is from the wing jib which has an efficiency factor of 1.9 and works efficiently to within around 10 degrees of the wind, where the old jib had an efficiency factor of .85 and could sail to within around 20 degrees of the wind.
Now all this is still theory, but my plan is if all this testing works out (which it has so far) is to replace the main sail with a free pivoting 80-90 sq ft wing sail (basically the same design as my jib (it's already all designed.... just got to build it)), and just using pedal power (no motor) be able to easily pedal my TI all day long in virtually no wind at 5-8 mph (even faster with two people pedaling). The wing sails have already proven out to have virtually no healing moment (trying to tip you over), and when not powered (zero angle of attack) they just let the wind go by with virtually no resistance so they should be really safe in gusty conditions with little to no risk of tipping the boat over if conditions change suddenly. Plus everything I make only takes one or two seconds to furl or unfurl, which makes transportation easy, I just furl them up, drop them from the halyard and lay them in the boat on the trailer (with all the furler and control lines still attached (that's what I do now)).
None of this is new, with my old sail setup which I built over 3 yrs ago, the main and my old jib I could sail while pedaling lightly all day long at 3-5 mph in virtually no wind at all(we all can with the TI's (with the addition of a jib) and the mirage drives). I'm just fitting more efficient sails (wing sails) to my boat to better what my boat can already do. The Tandem Island with it's mirage drives is totally unique in the world, and I don't even think Hobie fully realizes what they have designed (an extremely safe totally human powered boat that a normally fit person (or family) can pedal all day long at better than 8 mph (with wing sails of course)). There is nothing else in the world that can do this now or on the drawing boards anywhere.
Of course I still plan to keep my motor, if things get bad (and they do) out in open water (ocean), I can always furl the sails and high tail it home. And if the winds are 10-15 mph (which is only in a blue moon around here) I can still use just the standard TI with just the stock mainsail (no changes are made to the basic TI), which is a blast. And the with my improved spinnaker design even downwind will be improved (downwind is the weakest point of sail on both the TI, and wing sails), so I'll be keeping my spinnaker (plus it's the most fun to use, whether you need it or not, it's just fun).
Next time I go out in no wind I will take a video powersailing with my wing jib and we can compare the speeds from the above video.
Keep in mind something like this has virtually no interest whatsoever in the traditional sailing market, and traditional sailers mindsets and sail boats won't be changing anytime soon, after all sailing hasn't changed at all in the last couple thousand years. I'm just a quirky inventor and this just happens to be my hobby ( I own my own successful design engineering company (nothing to do with boats or sailing LOL)), and tend to think outside the box. I doubt there will ever be any market for anything like this, most people like their jet ski's and powerboats too much (well those that can afford to have them, I know I can't), I just try to think of ways to have fun on the water for free without polluting it (for my own self enjoyment as a hobby, and of course to keep my raging mind busy).
Bob


Last edited by fusioneng on Tue Jun 25, 2013 2:20 pm, edited 1 time in total.

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PostPosted: Tue Jun 25, 2013 2:20 pm 
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Bob, help me here, as I am confused.... If you really are in zero wind conditions, how can you possibly generate apparent wind which is not coming from exactly dead ahead? It this is the case, how can the sails possibly generate any lift?

I understand that if there is any wind coming from the side, other propulsion can add apparent wind speed, while moving the apparent wind direction towards the bow, but not if in zero wind conditions.

Am I missing something?

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PostPosted: Tue Jun 25, 2013 3:01 pm 
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tonystott:
No your not missing anything, when I say no wind, I mean not enough wind to propel the boat, I don't think there is ever no wind at all except in space. Basically as you can see in the video I am taking the available wind maybe 3-4 mph at best and adding the power of the mirage drive or motor to direct the wind over the sails so the apparent wind over the sails ends up being 7-8 mph when pedaling or 8-10 mph using the motor.You can do the same experiment yourself on the next calm day (most people don't bother going out when it's that calm). Just pull your full sail tight and start pedaling lightly, into the wind about 20 degrees off the wind seems to work best. For some reason that I don't understand fully it works way better with a jib, but it still works with just the mainsail. I'm guessing that by pedaling or driving with a small motor you are generating enough wind to create a vacuum in front of the sail to propel the boat faster than if you had no sail at all.

By increasing the efficiency of the sails (wing sails) I am able to amplify the wind even more than with the standard sail, that's all.
Bob


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PostPosted: Tue Jun 25, 2013 3:29 pm 
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Thanks for the clarification Bob, I was thinking of conditions like this for zero wind. When it is like that, the sails cannot do anything.
Image

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PostPosted: Tue Jun 25, 2013 8:18 pm 
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Tonystott:
I don't recall Sarasota bay ever being as calm and flat (no wind) as you show in your pic. During the daytime there is typically at least some wind 2-5 mph. These typical conditions are what I have rigged my boat for since 85% of the time I want to go out, these are the conditions I have to deal with.
Next very still day where there is literally no wind at all (like your pic) I will repeat my test (chances are you are totally correct, my sails won't do anything)
Bob


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PostPosted: Wed Jun 26, 2013 9:58 am 
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Love your mods Bob ... keep up the good work

fusioneng wrote:
(note: at around .30 into the video you can see the bow flexing up and down about 2 inches in the waves)


I think thats more of a camera abberation or whatever ... that same effect can be seen @ .25 on your blue bag as well as the clouds past your smiling face @ 2.35-2.55

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PostPosted: Thu Jun 27, 2013 9:23 am 
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tonystott :
Well you were correct I went out yesterday and was sailing with the jib and mainsail in low winds (4-6mph) the performance was pretty amazing to me sailing all points, upwind, downwind etc, that wing jib really helps in low wind conditions. I was able to sail pretty darn close to 1=1 with the wind on most points of sail. I even learned that on a straight downwind I can point the rigid jib to one side and the mainsail to the other and make a batwing, the performance was actually way better than I would have expected.
Then the wind changed and all went still (no wind at all), I tried my trick of pulling the sails tight and pedaling lightly and it didn't work. Apparently you have to have something to start with wind wise even if it's just 2-3 mph for the pedaling with the sails pulled tight to work (you were correct).

I then pedaled back to shore with my tail between my legs (defeated because my pedal power in 'no wind' ambitions are now dead (with my current wing designs, the 'no wind' pedal powered boat will require a totally different wing form and design)).

Just as I pulled up on shore the wind started back up but the winds were 30 mph (storms in the area). I had my wing jib open and free wheeling (neutral) on shore when it started to shake and luff violently in the 30 mph winds. I'm guessing that's the difference between a soft wing sail and a rigid wing sail. The soft wing sail is pliable enough to start oscillating like a flag would in high winds when not under load. So now it's back to the drawing board to design in oscillation dampers into the design. Fortunately as soon as trouble started I was able to easily furl the sail to prevent damage. as a side note, as soon as I put a load on it (pulling the control line to force the wing into an asymmetric shape the vibration stopped, and the sail would have been fine (in the 30 mph wind) as long as I kept it under load, but when in it's natural symmetric wing form (neutral) it oscillates in high winds (something that caught me by complete surprise, and I was not prepared for, I guess that's all part of trying out new concepts and ideas. Kinda like the guys trying to break the sound barrier (guys like Chuck Yeager) fortunately when my wing doesn't work as expected I can just furl it up and pedal back to shore (you have to love the TI's).
Even with this major setback I still firmly believe that wing sails are possible on small boats, and once perfected will be far superior to conventional sails. I'm stopping construction on the main wing sail until I've solved the aerodynamics problem, but will continue testing and using the jib but only in low wind conditions (under 15 mph).
I hope I'm not boring everyone.
Bob


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PostPosted: Sat Jun 29, 2013 3:58 pm 
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Well we had one of those once in a blue moon sailing days in Sarasota today, winds were 12-15 mph, In the summer we typically don't get this kind of wind.

I fixed the problem of the jib lufting and waving like a flag (and shaking violently), it appears since the wing sail is symmetric airfoils, until you give it an angle of attack, where it then self adjusts itself into and asymmetric airfoil. Well the problem was when the wind was blowing hard it would oscillate between sides, not knowing which way to go. In my original design I had planned on using slits on the leading edge to fill the inner portion of the wing with pressurized air to make the wings puff out. I had all the air inlets taped over during all my initial test and trial (not sure if I was going to need them). Well to make a long story short, (too late), opening up the air inlets solved the lufting problem completely. with the sail in neutral the sail fills with air and becomes quite rigid, and the air passes by it smoothly.

Here is a video showing the sail in 12-15 mph winds.
[youtube]http://www.youtube.com/watch?v=1-lucLodTQM&feature=youtu.be[/youtube]

I also want out into the wind with the mainsail furled and was able to peddle without difficulty upwind, downwind, reach, etc without the wind effecting the boat terribly with the sail floating in neutral. Of course there is some wind resistance from the entire boat when pedaling against a 12-15 mph wind so you still get your exercise pedaling into the wind, but the wing jib doesn't appear to make it a lot worse.

I kept the main furled and just sailed on the jib most of the time today (studying the airfoils shapes and performance on all points of sail), I can now safely state that in 12 mph wind I can sail the boat using just the jib at around 6 mph, which is way better than my old jib.
I did open up the main sail a couple times (furled 2 turns) and got up to ten mph on one reach in variable 12-15 mph winds. It was pretty choppy and that always slows you down, plus the wind was variable (not steady at all), which hurts on the TI's because they are so light.
All in all the jib is now mounted on the boat and there it will stay for quite a while, (I'm tired of messing with it), I'm just going to use it for a while, we are going down to Key West in a couple weeks, and will definitely use the heck out of it down there for a few weeks (Trade winds are fantastic down there). I don't have any additional adjustments or changes planned (finally done). The wing mainsail will be on the back burner for quite a while (I'm pretty burnt out on this stuff now, and just want to go out and enjoy it.
Bob


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