Fan on a sailboat...does it move?

[Blurred]

In honor of the airplane on a treadmill thread, I give you this.

So you fix a motorized fan on your sailboat, and ALL of it's moving air
is caught by the sail of the boat. Does the boat move, and if it does, in what direction?

[Powow]

The only way to move your boat is to put me in front of the sail and feed me beans.

[irul&ublo]

wing....

[GapersGoHome]

Oh, lordy... here we go.

[Beaver]

If the fan is mounted so that the air passes by the sail as wind does when sailing and not at a 90 degree angle to "catch" the air it will move forward until it gets to the end of the extension cord. Then it will drift until a 474 with no wheels crashes into it killing everyone on board.

[timvwcom]

If the fan is mounted so that the air passes by the sail as wind does when sailing and not at a 90 degree angle to "catch" the air it will move forward until it gets to the end of the extension cord. Then it will drift until a 474 with no wheels crashes into it killing everyone on board.

Said 474 with no wheels because some idiot was trying to take off from a treadmill and the wheels exploded...

[Core Shot]

Fucking 9,415 post JONGS don't know how to use the motherfucking search function

http://www.tetongravity.com/forums/s...ad.php?t=81387

RERUN, biaatch

[Blurred]

Fucking 9,415 post JONGS don't know how to use the motherfucking search function

http://www.tetongravity.com/forums/s...ad.php?t=81387

RERUN, biaatch

I'm just here for the entertainment of the back and forth douchebaggery...
Relax and laugh a little.

[Chiz]

Yeah it would totally work, but you'd need a HUGE fucking fan. As long as there is air moving over the sail and the sail is correctly trimmed, totally.
Im a sailor, and personally I prefer to get my boat moving by the dressing up like jesus and swinging my penis in the air and going WOOOOOOOOO!

fuck yeh

[dirtybryan]

If you are in a keelboat, you if you rock it side to side, it will also move forward.

p.s. psych majors are fucking dumb, i'm sitting in a psych course and the professor has been explaining mean, median, and mode for the past 15 minutes.

[Core Shot]

Relax and laugh a little.

Fully relaxed here. Just fucking with ya.

[Tye 1on]

depends on the tide.

[PNWbrit]

p.s. psych majors are fucking dumb, i'm sitting in a psych course and the professor has been explaining mean, median, and mode for the past 15 minutes.

Dumbassses. That's the one with ice cream

[freezorburn]

I want a taco that poops Ice Cream!!!

[pechelman]

Its called a propeller

[Jer]

On salt water of fresh water?

[Poop~Ghost]

you bastards, look what you did.

[mtnjam]

the sailboat would go nowhere...

I'm assuming that the sailboat and fan are in a perfectly controlled environment, no wind, no friction of the water, etc...

The fan pushing the air against the sail is ALSO pushing backwards. (every action has an equal and opposite reaction)

[Lurch]

the sailboat would go nowhere...

I'm assuming that the sailboat and fan are in a perfectly controlled environment, no wind, no friction of the water, etc...

The fan pushing the air against the sail is ALSO pushing backwards. (every action has an equal and opposite reaction)

^^^^ This

[dirtybryan]

the sailboat would go nowhere...

I'm assuming that the sailboat and fan are in a perfectly controlled environment, no wind, no friction of the water, etc...

The fan pushing the air against the sail is ALSO pushing backwards. (every action has an equal and opposite reaction)

That would only be true if the fan was placed at the bow pointed directly astern, however sailboats cannot sail directly into the wind. It would be true if it was placed directly behind the boat such that you might be sailing wing-on-wing or on a very broad reach. However if the fan is positioned such that it was blowing air across the boat, the keel would anchor any of the normal force of the fan.

[Registered_User]

Law of conserved momentum bro. The air hitting the sail can go in any direction except through the sail. Therefore it goes left right up down (all cancelling each other) and BACKWARDS. The backwards flow of air means that the boat must in fact go forward, but not as fast as if the fan were simply turned around.

[doughboyshredder]

depends on the current. If the boat is trying to sail through a channel and the oncoming current is equal to the amount of air being pushed by the fan, the boat will be moving in relation the water, but not in relation to the land. If the current is stronger the boat will go backwards. If the current is weaker the boat will go forwards.

[Lurch]

That would only be true if the fan was placed at the bow pointed directly astern, however sailboats cannot sail directly into the wind. It would be true if it was placed directly behind the boat such that you might be sailing wing-on-wing or on a very broad reach. However if the fan is positioned such that it was blowing air across the boat, the keel would anchor any of the normal force of the fan.

If the boat is going to move in any direction it will be backwards if the fan is pulling more air than the sail is catching.


Think of a hover craft or swamp boat. Now stick a sail behind it that only catches some of the air. The hover craft will still go forward but not as fast as it would if the sail was not there.

[Skipig25]

if the wind is low enough that you have to resort to using a fan, turn on the damn engine

[hutash]

Is the fan, and/or, the treadmill turned on? This makes all the difference in the world. Is the fan pointed forward or backward? What type of sails are set, and how are they trimmed? Norther or southern hemisphere?