GIRLYBOYS cat fighting again!!

I've returned to normalcy by simply plonking Larkin.

No agitation. No urge to lose my cool. No need to convince (and try to educate) idiots that the fundamental rule of Life, Physics and Engineering is "TANSTAAFL" :-)

Now I can ask and answer engineering questions without having to contend with distracting bloviation.

Those who choose to believe in Larkin's (and his camp followers') bloviation... well, that's their loss. ...Jim Thompson

=A0 =A0 ...Jim Thompson

And now, if you'd stick to electronics (and possibly barbeque renovation techniques) you'd be perfect.

-- Joe

Stick to electronics? Does JT talk about electronics any more?

John

No, please, Can you explain to me how this little vehicle goes uphill faster than the treadmill speed. Please!

Do the math. If I _give_ you the answer, you'll never learn to apply fundamentals.

If you think there's something "free", stop the belt :-) ...Jim Thompson

Certainly...

Consider a cart with a generator hooked to the rear axle. We'll attach the propeller (it IS a propeller - not a turbine) to an electric motor.

For the sake of argument I'm going to assume the following efficiencies:

generator: 85% electric motor: 85% propeller: 85%

And just for now... rolling resistance: 0 lbs aerodynamic drag: 0 lbs (we'll come back to these).

Now let's tow this cart up to 20 mph in a 15 mph tail-wind and let it loose. That means it will feel a relative head-wind of 5 mph over the cart. Now I'll adust my generator output until it produces 20 lbs of drag at the wheels. This means I'm putting power in at a rate of 20 mph x 20 lbs (400 mph-lbs). But I only get 340 mph-lbs out of the generator due to its limited efficiency. I deliver that power to the electric motor. But I only get 289 mph-lbs at the motor's shaft due to the motor's innefficiency. So I'm putting 289 mph-lbs into the prop - but it's only doing about 245 mph-lbs work on the air due to it's innefficiency.

So now lets see how much thrust I'm getting from my prop...

So we're producing 49 lbs of thrust and only 20 lbs of drag. But we haven't yet accounted for the rolling resistance and aero drag. If we can get both of those numbers to come in at a total of less than 29 lbs (which should be a piece of cake) we'll be going 5 mph faster than the wind and still accelerating. But why?

Simple. The car acts as a force multiplier (i.e. lever) between two media (the ground and the air). Just like any lever, I can get more force out of one end if I put more distance in the other. Force x distance =3D work, so those will nominally be the same on both sides. But my car is going over the ground at 20 mph while it's only going through the air at 5 mph. This means the ground side of my lever moves 20 miles in one hour while the air end of my lever moves only 5 miles in that same hour. With no losses I can get four times the thrust as the drag I produce.

But mph-lbs?

John

$ units

You have: mph*lbs You want: kg*meters/sec * 0.20277393 / 4.9316004

Good call - if you can't find any actual errors in the analysis, bitch about the units.

Certainly...

Consider a cart with a generator hooked to the rear axle. We'll attach the propeller (it IS a propeller - not a turbine) to an electric motor.

For the sake of argument I'm going to assume the following efficiencies:

generator: 85% electric motor: 85% propeller: 85%

And just for now... rolling resistance: 0 lbs aerodynamic drag: 0 lbs (we'll come back to these).

Now let's tow this cart up to 20 mph in a 15 mph tail-wind and let it loose. That means it will feel a relative head-wind of 5 mph over the cart. Now I'll adust my generator output until it produces 20 lbs of drag at the wheels. This means I'm putting power in at a rate of 20 mph x 20 lbs (400 mph-lbs). But I only get 340 mph-lbs out of the generator due to its limited efficiency. I deliver that power to the electric motor. But I only get 289 mph-lbs at the motor's shaft due to the motor's innefficiency. So I'm putting 289 mph-lbs into the prop - but it's only doing about 245 mph-lbs work on the air due to it's innefficiency.

So now lets see how much thrust I'm getting from my prop...

So we're producing 49 lbs of thrust and only 20 lbs of drag. But we haven't yet accounted for the rolling resistance and aero drag. If we can get both of those numbers to come in at a total of less than 29 lbs (which should be a piece of cake) we'll be going 5 mph faster than the wind and still accelerating. But why?

Simple. The car acts as a force multiplier (i.e. lever) between two media (the ground and the air). Just like any lever, I can get more force out of one end if I put more distance in the other. Force x distance = work, so those will nominally be the same on both sides. But my car is going over the ground at 20 mph while it's only going through the air at 5 mph. This means the ground side of my lever moves 20 miles in one hour while the air end of my lever moves only 5 miles in that same hour. With no losses I can get four times the thrust as the drag I produce.

Thanks Rick, I was hoping Jim would analyze it and start thinking hmm... maybe this thing isn't intuative and why is, that car going faster than the 0 mph wind. I find it interesting that there are so many nonbelievers with so many tests showing it works. One question, is the tacking of the prop necessary or could a flat blade prop work? Some videos seem to think that is the key, but your analysis would refute this. MikeK

Is this trick going to be your life's work?

John

Larkin is incapable of working with equivalent units. If mommy didn't give him a formula he's totally lost :-) ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

Spice is like a sports car... Performance only as good as the person behind the wheel.

I'm NOT a non-believer. Everything has an explanation that fits _both_ observation _and_ science.

MikeK, You seem to have trouble understanding what TANSTAAFL means ?:-) ...Jim Thompson

I'm not sure if you're referring to a prop with no twist or a prop with no pitch. The prop has to have at minimum an effectively positive pitch.

New topic: RETARDS CONSTANTLY CHANGING TOPIC HEADERS LIKE THE DUMB LITTLE PLAYGROUND IDIOTS (THEY/YOU ARE)

Good job, retard. NOT!

New topic: RETARDS CONSTANTLY CHANGING TOPIC HEADERS LIKE THE DUMB LITTLE PLAYGROUND IDIOTS (THEY/YOU ARE)

Good job, retard. NOT!

Hence the term, eh? It "pitches" pockets of air. A "flat pitch" prop is no pitch at all. No pressure differential on either face of the blades.

So whether folks contend that it works by displacing air behind the pitch or by creating a low pressure in front of it, it is still the same result of air being displaced, creating a linear stream, and thereby thrust.

Whether by progressive curl or flat face or otherwise, the net result has to be positive pitch.

No tickie, wet laundry. :-)

He sure busted you at one of the things you do best.

Bwuahahahahaha!