Merged DDWFTTW in a “Real” Wind

[humber]

And then continues to accelerate, all the way to 2.8x windspeed.
Irrelevant.
Average speed is also irrelevant.

It's an over-hyped scrap heap. Fragile, massive and slow.

 

[humber]

Of course as you're aware (but like to pretend otherwise), the propeller doesn't wait for wind speed to begin producing thrust. If it did, the vehicle could never reach wind speed on it's own.

And so never stops opposing the wheel. "well you see, the prop isn't ready until the wheels have reached the sublimation ratio of the rotational vector thrust coefficient"

You can mention it all you wish, but the blades of the spinning rotor act as sails from standstill to full speed -- this never changes nor stops happening at *any* speed from zero on up.
JB

Well, well. Now after strenuous denial, you are saying the prop is a sail.
Yet, it is not a sail to the headwind. How is that magic done?
Complete ad-hoc fabrication, no more so than the cart itself.

 

[3point14]

And so never stops opposing the wheel. "well you see, the prop isn't ready until the wheels have reached the sublimation ratio of the rotational vector thrust coefficient"



Well, well. Now after strenuous denial, you are saying the prop is a sail.
Yet, it is not a sail to the headwind. How is that magic done?
Complete ad-hoc fabrication, no more so than the cart itself.

What headwind? If it's acting as a sail it's moving at an angle across the wind, just like a sail, not into a headwind, surely?

 

[Subduction Zone]

You are confusing two different properties: The speed of a typical molecule and the movement of the air en masse. As I originally suggested, you and SZ were talking at cross purposes.

That is one of his debating methods. Use the wrong terminology on a question and then spend pages defending that nonsense. As long as he is not being attacked on points that he cannot defend for the cart he is happy. Notice how he goes into extreme hand waving mode to get rid of the simple animation that shows how the cart works, or "planet oil barrel" as he calls it. This is one of the questions that he will not answer. He still refuses to answer how the BUFC could charge through a cloud of dust, or why it matters if the cart was pushed by hand to any speed.

 

[humber]

What headwind? If it's acting as a sail it's moving at an angle across the wind, just like a sail, not into a headwind, surely?

Yeah yeah ...whatever nonsense you like to make up. There is not one text that supports the intellectually puerile notion of a tacking prop.

When I Ratant's carts are in the wind, the free-wheeler will thrash the geared cart.

 

[I Ratant]

You may find it helpful to pull the cart up to a portion of windspeed because of the stalled condition of the prop when the cart is stationary.

My cart takes about 3 grams to start it rolling; roughly 1/5th of yours.

.
I'm relying on the sail effect to get the cart moving.
Just takes a sneeze to get the freewheeling prop jobber-do going.

 

[I Ratant]

Yeah yeah ...whatever nonsense you like to make up. There is not one text that supports the intellectually puerile notion of a tacking prop. Rank amateurs playing at being scientists, and begging for records at any cost.

When I Ratant's carts are in the wind, the free-wheeler will thrash the geared cart.

.
Dunno 'bout that.
I don't look forward to all the walking to get to the things after they're released.
And hope they don't get too badly damaged when they hit something at the terminal end.

 

[humber]

.
Dunno 'bout that.
I don't look forward to all the walking to get to the things after they're released.
And hope they don't get too badly damaged when they hit something at the terminal end.

Well, I Ratant, perhaps you won't have to risk that. The geared cart may not even start, so the free-wheeler can stay safely in its box.
You could try and do what the BB has done. Put the larger sprocket on the prop. The gearing is then less effective, so preventing embarrassing backwards motion. The limiting case, and the optimal one, is to completely disconnect the prop from the wheel.

Changing the gearing works in when in front of a fan. The cart can be made to go either way. I too found that the wheels and gears I would like are not available from the model shops. But I did find wheels, and belt materials in a general hobby shop. The wheels are for making childrens' toys, and the thread for necklaces. Kynar, leather, silk, all sorts.

 

[mender]

I too found that the wheels and gears I would like are not available from the model shops. But I did find wheels, and belt materials in a general hobby shop. The wheels are for making childrens' toys, and the thread for necklaces. Kynar, leather, silk, all sorts.

Then some of us saved ourselves all that bother and loss of time and just ordered one that already worked.

The plans and parts list are still out there.

 

[temporalillusion]

It's an over-hyped scrap heap. Fragile, massive and slow.

Their cart is better at going dwfttw than you are at explaining how an airplane generates lift.

 

[I Ratant]

Well, I Ratant, perhaps you won't have to risk that. The geared cart may not even start, so the free-wheeler can stay safely in its box.
...

.
It did self-start!
With the prop going the "wrong way"!
It drove off into the dark..
Fortunately Sweet Thang dropped by, and getting laid is a lot fun than this.

 

[mender]

.
I'm relying on the sail effect to get the cart moving.

Pretend you're a big sail.

 

[mender]

.
It did self-start!
With the prop going the "wrong way"!

The wrong way being as a prop?

 

[humber]

.
It did self-start!
With the prop going the "wrong way"!
It drove off into the dark..
Fortunately Sweet Thang dropped by, and getting laid is a lot fun than this.

When free of the ground, and the rotor faces the tailwind, do the wheels turn as for forwards motion? If so, the cart is a downwind turbine.

 

[humber]

Their cart is better at going dwfttw than you are at explaining how an airplane generates lift.

It is better are fooling knaves.

 

[humber]

Then some of us saved ourselves all that bother and loss of time and just ordered one that already worked.

The plans and parts list are still out there.

You paid $40 for "your" pre-digested cart.

 

[mender]

You paid $40 for your pre-built cart.

Yes. You should have too.

 

[A.T.]

Dynamic Soaring

For those interested in how this works, here an explanation in simple terms:



The current record is 468mph:



Here is a slower one where you can see the glider better:

Apparently NASA develops an UAV based on DS:



http://www.suasnews.com/2010/09/2030/dynamic-soaring-concept-uav-from-nasa-the-albatross-pav/

 

[CORed]

Yes. You should have too.

Then he could have spent days finding an explanation of how it didn't really travel ddwfttw, but only looked like it did.

 

[I Ratant]

The wrong way being as a prop?

.
The prop was installed on the driven cart in the same orientation as on the freewheeler when the single wheel is pointing in the downwind direction.
With the connection to/from the wheels axle to move the cart forward with the "wrong way" rotation... CCW as seen from the rear. The same rotation the freewheeling prop runs.
With a healthy wind, it drove off downwind, but the freewheeler caught up to it.
Facing the driven cart into the wind, so the wind's rotation of the prop should move it upwind, it gave a couple of lurches towards upwind, but couldn't go forward.
Reversing the prop drive at the wheel axle so the prop goes CW viewed from the rear, as it is supposed to for this thing, in the light and variable winds today, which were more suited for thermal flying than anything steady, the wind at 1 foot up got to maybe 6 mph tops.
The freewheeler would take off like a scalded ape, but the driven cart would move about 5 feet, given a nudge with the foot.