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From: ThinAirDesigns on 13 Aug 2010 19:22
Ken Tucker:
>True, if the "Experiment" was conducted scientifically
>using a disclosed apparatus, method, including piloting
>procedures and ambient conditions,

The apparatus could not be any more disclosed at www.fasterthanthewind.org.
Hundreds of construction blog entries and over a thousand pictures.

The testing methods procedures and conditions are clearly detailed in
the two extensive reports on the www.nalsa.org.

Study up before making silly statements.

JB
From: Ken S. Tucker on 13 Aug 2010 19:24
On Aug 13, 2:29 pm, ThinAirDesigns <ThinAirDesi...(a)aol.com> wrote:
> Ken likes to make a lot of stuff up right off the top of his head.
> JB

It is contigent on you JB to disclose the socalled science of your
experiment, if there is any, NALSA has no scientific qualification.
Why do you fear our physics group?
Why do you fear using the scientific method?
Why do disparage those who are curious about your claimed
accomplishments?
Why do you insist we take the word of others on blind faith?
Ken
From: ThinAirDesigns on 13 Aug 2010 19:44
Ken, you have ignorantly claimed that the energy stored in the
propeller was used to accelerate the vehicle for the record run. I
challenged you to produce the math showing that there was enough
stored energy in the system to do such. I provided you with the
needed specs to do so. You have not done so.

I will repeat the information and the challenge.

************************
(posted for Ken previously to a different list)

Tire diameter = 27"
Drive axle sprocket = 23t
Prop axle sprocket = 65t
Prop and hub weight = 22lbs (10kg)
Prop diameter = 17ft
Prop shaft (1.25" diameter) weight = 7lbs
Vehicle weight (with pilot) = ~600lbs

Now use 10mph as the starting point (that was wind speed) and you'll
see that the prop was spinning at ~45rpm at that point.

So, for now I'll leave it to you to produce the math showing the
energy stored in the prop at 45rpm, and also in the vehicle at 10mph
and also the enegy needed to accelerate the vehicle to 28mph (the
speed we reached with the 10mph wind)

Good luck with what you find.

JB

PS: go ahead and assume that the prop's weight is distributed
equally
across the blades. Most of the weight is in the hub of course which
will make the math turn out in *your* theories favor and not ours --
but that's OK. You'll need more help than that to give your theory a
prayer.
****************************

From: ThinAirDesigns on 13 Aug 2010 19:48
Ken likes to claim all sorts of things about us being "scared" and
"withholding data" etc., but truth is he simply runs away every time I
try to get him to produce the math to support this theories while I'll
happily produce the math that supports ours.

Let's see who's afraid of this physics group -- you post your math and
I'll post mine. We'll see which treatment best models the behavior of
the vehicle.

JB
From: ThinAirDesigns on 13 Aug 2010 20:09
Following is a simple force/energy analysis I previously presented on
the other thread:

************************
A:
1.0 HP = 550 foot-pounds per second
(http://en.wikipedia.org/wiki/Horsepower)
This means that @55ft/sec, 10lbs of force exerted on our chassis will
allow us to harvest 1.0hp from our wheels with a lossless generator
(we'll deal with losses below)

B:
1/2HP = 275 foot-pounds per second
This means that at 27.5ft/sec, 10lbs of force can be produced by a
lossless propeller consuming 1/2hp. (we'll deal with losses below)

C:
If the wind is blowing at 27.5ft/sec and our vehicle is traveling DDW
at 2x the speed of the wind, the vehicle is traveling over the ground
at 55ft/sec and through the air at only 27.5ft/sec.

D:
Through the establishment of "A", we know we can pull 1.0 HP from the
wheels of the vehicle if it's propelled by 10lbs of force, and through
the establishement of "B" we can see that the propeller in the
relative tailwind only needs 1/2HP input to produce that same 10lbs of
force.

E:
We subtract the 1/2hp that the prop needs to produce its 10lbs of
thrust from the 1.0hp that the wheels can produce from that same 10lbs
and you have 0.5hp left over for the system losses.(told you we would
get to losses).

Do the same calcs on a no wind day and it's easy to see that the
wheels still produce 1.0HP at 55ft/sec, but now the propeller is force
to do work at 55ft/sec rather than 27.5ft/sec and it now takes a full
1.0HP at the prop to produce the 10lbs of force. This of course means
that there is nothing left for losses and since there is *always*
losses, the vehicle simply can't motivate.

In the real world we don't have lossless components of course. If you
consider an 85% efficient propeller (easy to achieve) and an 85% drive
train (even easier to achieve) and we've still got nearly 1/4 HP left
over for the Crr of the tires (very low for high pressure bike tires)
and aero drag.

There's no magic and no laws are violated. It's a simple but unusually
looking application of long established principles.

You say that we used stored energy to accelerate -- I just showed that
there is no need to use stored energy.

I urge you to publicly critique my math above and I eagerly await your
treatment showing how we used the energy in our propeller to
accelerate from 10mph to 28mph as we did in our record run.

How's that for "fear"?

JB
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