Forums > Windsurfing   Gps and Speed talk

Two sails instead of one? Push or Pull rather ?

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Created by Macroscien 1 month ago, 26 Nov 2020
Macroscien
QLD, 5664 posts
26 Nov 2020 11:38PM
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If there were any attempts already to use two sails setup instead of one for windsurfing competition?


all the fastest sail boat use small sail on the front to power main sail. can we do the same one day ?



or sail wing design is still be best and quickest of all?



Macroscien
QLD, 5664 posts
26 Nov 2020 11:53PM
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If we look at mechanics of the fastest sailboat and try to utilize for our windsurfing need,
it may looks like that


our sailor now is standing on opposite side of sail.
Is no longer pulling the sail , but pushing against.
Wind is trying to push boat into the water, not to rise up.
The stronger the wind the stronger the forces and there is no upper limit of the wind speed.
???
All forces now try to sink the board , which force now can be converted into speed without the risk of flying into air.Weight is not longer needed to kept counterbalance to the sail.

Macroscien
QLD, 5664 posts
27 Nov 2020 12:02AM
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or even designe where our mast base is relocated far to the side of the board, a meter or more against the wind

from aerodynamical point of view sailor position is be best ,because airstreem at this side of airfoil is faster the on the other side
and sailor is creating resistance to this air flow...optimally sailor be in .... horizontal not vertical position !!!!

sailquik
VIC, 5315 posts
27 Nov 2020 1:34AM
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Foresail setups (Jibs?) on windsurfers were built and tested but a few sailors from the earliest days of windsurfing. They didn't catch on.

Then there is this which works in a similar way and actually does work:

ZeeGerman
166 posts
27 Nov 2020 8:52PM
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Yeehaaaa!
This Speed Tandem is still a favourite of mine.
Macro, you're completely mistaken on the Vestas sailrocket: The sailor is sitting on the windward side, with both hulls planing and a windward supercavitating foil holding the whole boat down.
Watch the video where their prototype fails and you'll see that the wind of course pulls up!

When trying to improve efficiency in sailing, we should at least know where the wind comes from.

ZeeGerman
166 posts
27 Nov 2020 8:56PM
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55 seconds in:

sboardcrazy
NSW, 7217 posts
28 Nov 2020 2:29PM
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Select to expand quote
ZeeGerman said..
55 seconds in:


That's spectacular! I bet that hurt, both in the body and hip pocket..

Macroscien
QLD, 5664 posts
28 Nov 2020 9:52PM
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ZeeGerman said..
55 seconds in:


Perfect example. That only means that my idea apply to Sail Rocket too.When you change the wind direction and wind will be pushing onto your sail, down, then is not upper limit of wind speed and boat speed. All excess of wind power will be converted into speed and boat will never get into airborne.Like F1 car that could drive in tunel upside down, due to sucking forceass.So you need to excuse my naivety, - I didn't expect Rocket Builder to make this fundamental mistake !! Obviously the angle of wind direction will need to change dramatically when sail will be tilted in other direction and pushed down by wind, not up.

Macroscien
QLD, 5664 posts
28 Nov 2020 9:59PM
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Select to expand quote
ZeeGerman said..
Yeehaaaa!
This Speed Tandem is still a favourite of mine.
Macro, you're completely mistaken on the Vestas sailrocket: The sailor is sitting on the windward side, with both hulls planing and a windward supercavitating foil holding the whole boat down.
Watch the video where their prototype fails and you'll see that the wind of course pulls up!

When trying to improve efficiency in sailing, we should at least know where the wind comes from.


ok I did make this small changes for you,
Here is improved Sail Rocket 2,
main goal - go above 100 ktn!


ZeeGerman
166 posts
28 Nov 2020 8:20PM
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Ah, here we go! Your idea wasn't clear to me.
If you really want to turn the whole thing round and have a sail that leans to leeward that much, nobody can accuse you of not thinking widely out of the box. I don't see any potential benefit in it, but might just be blinded by conventional wisdom.

Macroscien
QLD, 5664 posts
28 Nov 2020 10:32PM
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ZeeGerman said..
Ah, here we go! Your idea wasn't clear to me.
If you really want to turn the whole thing round and have a sail that leans to leeward that much, nobody can accuse you of not thinking widely out of the box. I don't see any potential benefit in it, but might just be blinded by conventional wisdom.


If the idea is/was so obvious , we should have boats according to my project sailing already everyday. Then my input here completely useless. But that don't bother me too much. I get this experience everyday that something just invented by me is well know already for long time and some guys get even good reward for it, Being second don't give you a Nobel .
Even worse- flout / sneer of not being well educated in recent developments and scientific achievements.

sailquik
VIC, 5315 posts
6 Dec 2020 10:40AM
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Macroscien said..
If there were any attempts already to use two sails setup instead of one for windsurfing competition?


all the fastest sail boat use small sail on the front to power main sail. can we do the same one day ?


As I said, it's been tried many times.

eg: I just saw this picture:


Astute comment from Nils Rosenblad:
"10% more lift, 50% more drag, and 100% more weight!"

Macroscien
QLD, 5664 posts
12 Dec 2020 4:28PM
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If we look at famous Moth
we could see that foil is installed beneath mast base.It seems also that sailor don't need constantly control depth / high, somehow it is all done automatically.
But what we possibly don't want - is a rudder in our windsurfing boards.


fb.watch/2k7eAyqC2q/

sailquik
VIC, 5315 posts
12 Dec 2020 8:03PM
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Select to expand quote
Macroscien said..
If we look at famous Moth
we could see that foil is installed beneath mast base.It seems also that sailor don't need constantly control depth / high, somehow it is all done automatically.
But what we possibly don't want - is a rudder in our windsurfing boards.


fb.watch/2k7eAyqC2q/


There are elevators on both the main wing and the rudder. The Main wing is auto controlled by the 'wand', but the rudder is manual by the sailor



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"Two sails instead of one? Push or Pull rather ?" started by Macroscien