Directorly Downwind Faster than the Wind

[ramset]

Greg
my favorite part is when he stalls the telltales and keeps on truckin.
makes my head explode!

Seems like it really wouldn't need any wind,  dare I say
"It can make its own"

http://en.wikipedia.org/wiki/Apparent_wind

Chet

[sparks]

Sailing was explained to be as the action of squeezing an oiled jellybean.  It pops forward if the hull is shaped correctly.
Pullup the centerboard in a boat on what is called a reach or when the wind is perpendicular to the hull and you start sliding sideways in the water slowly.  Instead of decreasing drag on a vehicle perhaps we should actively manage it.  Put a big funnel and drive the apparent wind through a turbine.  The drag will turn into more useful production.  Instead of the car creating a low pressure vortex or draft behind it which the car always wants to go back into the low pressure area is set up in front of the main body of the car in the shelter of the turbine.

[TechStuf]

Instead of decreasing drag on a vehicle perhaps we should actively manage it

Spoken like a tried and true Schauberger afficianado!


I would even go so far as to say that micro-management is in order.


I'll have a double Schauberger to go....and make it snappy....


I've got places to go and people to see!

[Cloxxki]

The cart makes its own wind, perhaps, but it's the apparent headwind powering it past the wind speed.
The prop sitting ON the cart must be scooping up air at a modest rate. To high a rate, and the drag of the prop will slow down the wheels, or they lose traction.

I have some sketches here also, funnel shape with a large prop front, small prop rear. It can do what we want, but will the tailwind be sufficiently impressed to push the cart out in front?
Without wind, from standstill there is just a massive wall or air in front, and no thrust. And at 10mph kick started speed, generating a little bit of power on the funnel, we can't expect the system of props to generate more more than Mr Hand used to get the system to 10mph. For, that's what we need to do away with nature's wind input. That's a lot of wind to make from scratch!

If one builds the little cart Spork offers building vids for, it may be interesting for those who smell OU, to try some gearing and kick start speeds, to see if it'll keep going. The smartest guys in this field, Spork's team, are not betting on this. They go for actual wind, however weak, and build a low-drag cart that can use the mechanical advantage to get better speeds than a ballloon.

If ice racers do 5x the wind speed...(200mph, is that in Guinness??) it would be interesting what a DDW cart can do. A prop may be less efficient that an airfoil, but when geared well, at least it has not frontal drag, it pulls harder than it pushes.

With a refined system of foldaway airfoils and props, a cart could on a windy day set repectable lap times around a typical car racing circuit. Only but: wind must be blowing.

For the slow acceleration up to wind speed, I would recommend a simple sail. Like a projector screen, it rollsup into a frame tube when the wind speed is matched :-) A set of small support points would make it an efficient sail shape.

Requiremensts for a DDW race cart:
- big prop (unless an over-geared small prop can be substituted, I doubt it)
- tiny cockpit
- all other parts reduced to minimum resistance : structures, wheels, everything.

The amount of force at a given wind speed acting upon the cart from behind, with it's self-backspinning rotor, minus the drag on all the parts, is what's left of acceleration.

Yes, lots of research into prop, yet not giving the actual wind movement relative to the ground much thought, we are after all making air speed, not ground speed? I also have a sketch here of an airship dragging a heavy cart, to get mechanical movement transferred. A really better idea for the feedback loop, I do not have.

Could we make a track of reppeling magnets, the other set in the vehicle, for maglev?
With wind, the magnets running by each other would be like a turning wheel, this could be extracted. We have to use it for a low-tech prop however, can't let another wheel turn faster, as we'll only end up with resistance greater than gain. At low apparent wind, the prop is just marvellous thing for lift vs drag.
Can you see it? A levitation craft, with a prop on its tail. It needs a magnetic track though, or it'll crash down. When you add vertical lift airfoil, and pedals, you have what I one dy intend to build, a human powered ground efect plane. These have existed (cross the Channel) in the bi plane variety, and worked, but I want something smaller and faster.

[Cloxxki]

@Rapadura, I seem to have mis-read your post above I responded to, or maybe your edited it. Anyway, my apologies.