Direct Downwind Faster Than The Wind #5 (DDWFTTW)

[hawaiianduke09]

Hey Spork33,

I was unconvinced until I watched several of your videos. Now I believe you and I think I understand the physics. I was wondering where you're located. I'd love to have you come and demonstrate this to a few of my colleagues at the American Physical Society, if you happen to be anywhere near Washington, DC. If not, I guess I'll have to build my own.

Thanks,

James

buzzskyline@yahoo.com

[spork33]

@hawaiianduke09

Unforutunately, I'm pretty far from D.C. I live in the San Francisco Bay Area. I've posted a detailed set of build videos however. You can find them under my YouTube name "spork33".

[drbitboy]

The statement at 0:49-1:05 irrelevant at best and incorrect at worst. There is kinetic energy being continuously added to the system.

The key to thermodynamics is drawing the boundary box correctly.

[spork33]

@drbitboy

We understand thermodynamics just fine. Perhaps you don't understand the statement.

[drbitboy]

@spork33 You are right and I was wrong. I posted that without thinking it through. I drew the box right, but I didn't understand it, which is worse. I apologize for that and for my arrogance (and for the lost opportunity of you toying with me;-).

I joined boatdesign as sirclicksalot and am waiting on kiteforum; see you there. Do you still need a monitor?

This is fantastic.

[spork33]

@drbitboy

No apology necessary. I'm glad we're on the same page. I think I've got a monitor lined up, and should have it in the next few days. Do you have something available if it doesn't work out?

[Mrengineerwannabe1]

wasn't there something like this on Daily Planet??

[spork33]

@Mrengineerwannabe1 Yes, they did aired a segment on our full-sized vehicle two nights ago.

[Damien59999]

Any luck having Mythbusters verify your cart yet? Looking foreword to it.

[timy2k2]

I don't know what VMG is but 49er's SK4's Foiling moths and several other high performace sail boats can exceed wind speed down wind. this does not conflict with any laws of physics because they are moved by differnces in air pressure not wind speed.

[spork33]

VMG stands for "velocity made good".  This is used to indicate the projection of your velocity in the intended direction of the goal. No traditional sailboat can go directly downwind faster than the wind. Some can achieve downwind VMG faster than the wind by tacking downwind.

[timy2k2]

There are ways to achieve down wind faster than the wind. Some sail boats achieve it because of their hull design in conjunction with the aerodynamics of the sails. Downwind the combination of air pressure pushing from behind and appearent wind over the airfoil created by the sails can combine to more than compensate for drag and thus the boat is somewhat faster than the wind speed( don't confuse with pressure )

[spork33]

There are sailboats that can achieve downwind VMG faster than the wind; but none can go directly downwind faster than the wind. What would anyone be confusing with pressure?

[timy2k2]

The tread mill is your "power source" spinning the drive wheels fast enough to spin the fan at a high enough rate to move the vehicle foward and up a slight incline. If it was engineered a little better it would go faster but your propeller is very inefficient, it looks like the one that comes with a rubberband powered airplane. there is no great scientific break through here and you have not explained how the vehicle can travel down wind faster than the wind.

[spork33]

Yes, the treadmill is our power source when measured in the fixed frame of the ground. Just as the wind is the power source when operating on the open road. The two situations are equivalent.

I've made no claim to any breakthrough whatever. Nor do we claim that this video describes how it works. I have however explained it in great detail on a number of forums. Thanks for the advice on the prop. I'll be sure and make a note of it.

[ambphysis]

@timy2k2 you are ignoring galileo's principle of relativity

[TimpBizkit]

Because the propeller is pushing against still air not a 10mph wind, it only needs to provide enough thrust to support its weight and the wheel resistance. A large light slow moving propeller is the most efficient way of doing this.

[Damien599999]

This works because there is no air pushing against the cart slowing it down, so, any wind created by the fan, just pushes it foreword. If this were on the ground, going that speed, it would be constantly slowed down by air friction, but using the treadmill, there is no air friction slowing it down, because its not moving through the air foreword. Neat video tho.

[spork33]

Nope - the treadmill turning 10 mph in a room with no wind is identical to a 10 mph wind over a stationary road.

If you are going downwind at exactly the wind speed you're not going to feel any wind.

[candybubbles]

noob

If the world is ran by your poor logic, then airplanes won't even take off anymore (because O NO!! THERE IS AIR FRICTION).

However, our world is not ran by you, so airplanes uses the same fuel to take off towards east or west. (I am saying this because the earth spins. lol duh)

[1highclassgent]

wow, you answered my comment on vid4 1 month early like a psychic - with a spork

[Outlander11]

Basically the gear set in the trike is turning the fan fast enough to produce sufficient thrust to go faster than 5mph.

either up the gear ratio more, or use a 4 blade fan at the same weight as the old one. The trike will increase in speed up the treadmill even more.

[TimpBizkit]

It is actually better to lower the gear ratio slightly, then compensate by upping the speed of the treadmill. This will reduce the frictional force generated by the wheels as they spin the propeller. Try upping the gear ratio too much and there will be so much friction that the vehicle will be unable to advance fast enough to move the fan. It will be shoved violently off the treadmill.

[Outlander11]

Why does no one understand that it is not perpetual motion? It is simply gear ratio increase.

If a static object is placed on the 5 mph treadmill it will go backwards at 5mph.

If a object like in the movie is placed on the treadmill with a 1:1 ratio(not 1:1 gear ratio, 1:1 in terms of 5mph tread -to- 5mph capable fan thrust for the object, or how much thrust it takes to go 5mph) it will go same speed

If the ratio increased 2:1, the object goes "uphill".

Damn character limit.

[tautologies]

Fantastic Spork super nice job on it...do you think Mul will start believing in science now? :-)

[spork33]

I suspect he would find this to be solid evidence for the creator : )

[davidglover]

It is obvious that you have magnetized (in some way) your plastic spork - which is actually a much bigger breakthrough - what are you really hiding?