Re: Mobile S-Rotor!


daestrom wrote:
> "TomGee" <lvlus@xxxxxxxxxxx> wrote in message
> news:1134186359.501568.66520@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > daestrom wrote:
> >> "TomGee" <lvlus@xxxxxxxxxxx> wrote in message
> >> news:1133992847.677395.71000@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> >> > K. Jones wrote:
> >> >> "TomGee" <lvlus@xxxxxxxxxxx> wrote in message
> >> <snip>
> >> >> Couple of points.
> >> >>
> >> >> 1. Car alternators don't use nearly as much horsepower as you think,
> >> >> and
> >> >> the
> >> >> belt-pully power transmission is far more efficient than any wind
> >> >> turbine.
> >> >> Most cars have between a 35 amp to 65 amp alternator......12 volts *
> >> >> 65
> >> >> amps
> >> >> = 780 watts 1 HP = 746 watts. Even a heavy-duty 100amp alternator is
> >> >> less
> >> >> than 2HP, and that's at full draw.
> >> >>
> >> >>
> >> > I don't know where you're getting your information, but the hp
> >> > requirements from the vehicle engine to turn the alternator have always
> >> > been set at 15 hp and above. The smallest estimate I could find was 4
> >> > hp. Most large vehicles don't use the puny car units, they use up to
> >> > 250 amp alternators. My device uses belts and pulleys too so how could
> >> > it be any less efficient?
> >>
> >> 250A x 12V = 3000 watts. If the alternator is only 75% efficient, then
> >> the
> >> engine must supply 4000 watts to drive that alternator under full load.
> >> 4000 watts is only about 5 hp.
> >>
> >>
> > You must be missing something or else everyone else who claims it takes
> > 4-30 hp to turn alternators is wrong about the upper end.
>
> Even with an alternator that is only 50% efficient, and a belt drive that
> was only 50% efficient (neither of these are true, alternators and belts are
> much more efficient than 50%), 3000 Watts output would only require 12000
> watts input. Can you convert 12000 watts to hp?? (the answer is 16).
>
> Typical load is much lower than 3000 watts though. An 86 amp truck
> alternator loaded to 75% would only be 774 watts (unless it's 24V system,
> then it would be 1548 watts).
>
> Who is 'everyone else'?? And where do they get their information?
>
> >> >>
> >> >>
> >> >> Vehicle alternators run at much less
> >> >> than max capacity most of the time. Even if it could work (it can't),
> >> >> who
> >> >> is going to put a light-bar sized box on the roof of thier car for
> >> >> about
> >> >> 1
> >> >> HP difference? You'd never be able to tell the difference.
> >> >>
> >> >>
> >> > I wouldn't and neither would you. It is true that alternators run at
> >> > much less than max capacity most of the time, that's why the actual
> >> > average hp usage to turn the alternator is hard to pin down on any
> >> > vehicle. Transportation industry vehicles are more likely to run their
> >> > alts at higher than average automobile capacity. It is more
> >> > cost-efficient to use an alt that loafs along most of the time and only
> >> > occasionally achieves max power. That's not the point. If my rotor
> >> > saves gas - which I at first hoped would amount to about 1.5 to 2.0%
> >> > fuel usage, has only one moving part, and has a ROI of within a year,
> >> > the transportation industry should quickly see they all must use it to
> >> > remain competitive, and as a taxpayer, I would insist that all govmint
> >> > vehicles use it.
> >>
> >> I would insist that your device pass some clinical trials before
> >> burdening
> >> the tax payers with this idea.
> >>
> > You don't have to, as no one including myself can be convinced unless
> > independent testing shows positive returns.
>
> Then it is premature to be talking about mandating it on govmint[sic]
> vehicles.
>
> >> >>
> >> >>
> >> >> 2. There is no "energy" from the wind flowing over the car, unless
> >> >> the
> >> >> car
> >> >> is not moving (parked). You have to imagine the car moving through
> >> >> essentially stationary air, like a boat travelling through stationary
> >> >> water.
> >> >>
> >> >>
> >> > I know it sounds counter-intuitive, but it works both ways. We can say
> >> > that the car moves through the wind at 60 mph or that the wind moves
> >> > around the car at 60 mph. I thought the same thing at first, so my
> >> > first test of my first model was to see if there really was power in
> >> > the wind created by a moving vehicle. Holding the rotor out the window
> >> > while my van was driven from a stop to 55 mph, its rpm increased
> >> > proportional to the van's increase in speed. At 55 mph, it was turning
> >> > at 70 rpm, and that sure surprised me! Your no. 2 is wrong as my test
> >> > shows that there is indeed energy in the wind created by a moving
> >> > vehicle.
> >>
> >> 70 RPM, but at what torque?? Developed power is speed times torque. If
> >> you
> >> can stop your device with one hand, then the torque is probably pretty
> >> low
> >> and the overall power low.
> >> <snip>
> >> >>
> > My point was that there is energy in the wind both ways. Did you note
> > that it turned faster than the speed of the air passing through it? I
> > did not measure the torque yet. that was an early model to see if
> > there was energy in the wind created by a moving vehicle. But your
> > point about torque is well-taken. And I have ideas about that too.
> >
> > The lift-types get their torque from the length of their blades because
> > lift is created along the length of the blade. The longer the blade,
> > the more torque that can be developed. That's why we have those huge
> > propellers planted in wind farms that power large power grids. That
> > type of torque comes from the lift effect that pulls the blades around
> > the axis, similar to the lever principle where the longer the lever
> > "handle", the more torque that can be generated.
> >
> > But IMO the drag-types develop torque in an entirely different way.
> > The torque developed comes from the third law of motion often called
> > the law of action and opposite reaction. The 3rd law states that
> > momentum is conserved in interactions between two objects. If two
> > basketballs are thrown so that they hit in mid-air, they will move away
> > from each other about an equal amount depending on the momentum of each
> > when they hit.
>
> Yes, yes, we all know how a moving fluid imparts a specific impulse to an
> object in its path. The magnitude of the impulse is related to velocity,
> density, the angle of deflection, etc... But all of that still doesn't
> violate the conservation of energy. No matter how much energy the wind has
> moving past the device, the device can't extract more energy than is in the
> wind. And the second law, the device won't even be able to extract all the
> energy from the wind.
>
> >The wind hits the bluff blades of my device and causes
> > rotational torque because the blades can only turn about their axis.
> > But there is a proportional and opposite reaction by the blades to the
> > wind, and how strong that reaction is depends upon the momentum of each
> > at the time they hit.
> >
>
> Take it a bit further why don't you. When the wind hits the blade, the
> blade tries to move straight back. But the axis prevents one side of the
> blade from moving, so the result is two forces on the blade, one pushing it
> back from the wind hitting it, the other is the force of the axis holding
> one side of the blade from moving. The result is a 'couple' which generates
> a net torque on the blade moving it around the axis.
>
> And again, 3rd law, for every action there is an equal and opposite
> reaction. When the axis exerts a force on one side of the blade, keeping
> the blade from moving straight back off the vehicle, the blade exerts a
> force on the axis. So the axis has a force acting on it, pushing it towards
> the rear. Similarly, the bearings of the axle and so on, until we get all
> the way down to the vehicle itself. So the wind pushing on the blade also
> acts to slow the vehicle down (i.e. the blade sticking up in the airstream
> adds drag to the vehicle).
>
>
Are you still under the wrong impression that I claimed my device adds
no drag?
>
>
> > Two completely different ways to develop torque, but the latter has
> > been completely overlooked in reference to its design and the result is
> > that the same principles that apply to the lift-types are also applied
> > to the drag-types, but wrongly, as I've said before.
>
> Not overlooked.
>
Oh yes, overlooked.
>
> You're just mis-informed about what has, or has not been
> considered in designing vehicles. Your device isn't already mentioned in
> the literature because it is a less efficient way to drive an alternator
> than a simple belt system.
>
No. My device is mentioned in driving an alternator. The S-rotor
works and is used by many to produce power from the wind -er,
slipstream. But here again you show that you are under the wrong
impression that my device uses no simple belt system. I hope to be
able to change its belt system to a direct-drive system, which is even
more efficient that the belt system it has now.

> Nor does the literature mention driving
> alternators on vehicles by using falling water or a friction wheel in
> contact with the ground underneath the vehicle. Many ideas are not
> referenced in the literature simply because they are obviously impractical
> and need no further review.
>
What I'm reading here is your opinion that my device is obviously
impractical and needs no further review than yours, is that correct?
>
> Even if you completely ignore the exact method of developing torque, you can
> still analyze the 'system' from an energy in/out standpoint.
>
> Your whole design is based on the premise that you can run an alternator
> with a 'wind device' using less engine fuel than an alternator driven with
> a conventional belt drive. You seem to believe that the drag created by
> your 'wind device' will not require as much power as a conventional V-belt
> drive.
>
No. You have misinterpreted what you read. My device will not require
as much energy from the vehicle engine to push it through the
slipstream as the vehicle alternator requires from the vehicle engine
to produce the electrical power needed by the vehicle.

As far as impractical ideas go, can you see why it is better to use a
belt drive system on a car than to use a direct-drive system instead?
After all, direct-drive is more efficient that a belt 'n pulleys
system, no?
>
> The amount of hp used by an ordinary alternator is not really relavent,
> since your 'wind device' would have to supply the same amount of hp,
> regardless of the exact value.
>
Certainly it's relevant, why else have you bothered to argue the point?
It's relevant to know how much hp is used by the alt. from the engine
so as to determine the amount, if any, of hp saved when disconnecting
the alternator from the veh. engine. If my device saves on fuel usage
or not, how can we know that without knowing how much fuel the veh.
engine uses to turn its alternator?
>
> You haven't proposed a new, more efficient
> way of converting mechanical power to electrical (whether the mechanical
> power comes from engine shaft, or S-rotor shaft doesn't change the
> alternator).
>
Yes, I have. My improvements to the S-rotor make it much more
efficient than the generic model. Enclosing it allows the slipstream
to be funneled into it and compressed to increase its momentum.
Downsizing it allows for the combining of several rotors for smoother
and more powerful applications, and makes it possible to be used in
mobile applications. Specially designed blades take advantage of the
lift-effect and more efficiently impact the second blades.
>
> So, *if* a particular, large alternator requires 27.3435222 hp from the belt
> drive off an engine to drive it, your S-rotor would have to develop the same
> 27.3435222 hp to drive it. How big would your 'wind device' need to be to
> develop 27.3435222 hp?? How much increased drag would such a device induce
> on the vehicle? How much more hp would be needed from the main engine to
> push this extra drag through still air? (I'll give you a hint, it's more
> than 27.3435222 hp).
>
So according to you, it will take more hp to push my device through the
slipstream than it takes for the veh. engine to turn its own
alternator, correct?
> >>
> >> >> Energy has to be expended to push the vehicle through the air, to push
> >> >> the
> >> >> turbine through the air. As the turbine is less than 100% efficient,
> >> >> it
> >> >> will always take more HP to push the turbine through the air, than can
> >> >> be
> >> >> extracted from the turbine.
> >> >>
> >> >>
> >> > That's fine so long as the hp required is still less than the vehicle
> >> > engines requires to turn it own alternator. My calculations show that
> >> > it takes about 1 to 2 hp for the vehicle engine to push my rotor box
> >> > than it takes for it to turn its own alternator, which is from 4 to 30
> >> > hp.
> >>
> >> But if your box only adds 1 to 2 hp to the vehicle engine demand, it
> >> cannot
> >> develop more than 1/2 to 1 hp output. So it couldn't drive even a 100
> >> amp
> >> alternator. Can't get out more than you put in.
> >>
I cannot figure out what you mean by your statement above. Are you
saying that my device can only get 1/2 hp of what it takes the veh.
engine to push it? How do you figure that? You are confusing two
distinct and non-equivalent principles as being applicable to the same
situation.
>
> >> Your device would convert engine power in the form of drag, to mechanical
> >> power at no better than the Betz limit (and probably a lot less), so
> >> you're
> >> already down to 59% of the power from the engine. A belt driving an
> >> ordinary alternator is much higher than that.
> >>
> >>
> > The Betz limit does not apply to drag-type rotors, only to the
> > lift-types, because it has to do with the area swept by the blades
> > which is used to provide the lift to turn the blades.
>
> Actually, the Betz limit *does* apply.
>
No, it does not.
>
> If you look at the fluid flow in/out
> of *any* device with the same pressure/elevation/density between the inlet
> and outlet, the power calculations still yield no better than the Betz
> limit.
>
So how do you figure that about my device?
>
> You can only get above 59% power extraction if you have a difference
> in pressure/elevation/density between inlet/outlet.
>
Okay, let's take the inlet of an airfoiled wind propeller as its swept
area and its outlet as the area behind the blades. The
behind-the-blades area has a lower pressure as the result of having
passed by the blades. By your argument, the Betz limit doesn't exist!
>
> In fact, the derivation
> of Betz doesn't even care about the nature of the device used.
>
Betz wrote it wrt airfoiled propellers and their relationship to the
slipstream area through which they sweep. If he had been asked if it
applied to drag-type rotors I'm sure he would have answered no.
>
> It could be
> any sort of 'black box' device with any manner of mechanism inside it and
> the derivation is still the same. It just happens that wind turbines is the
> most common application/reference on the internet of the limit.
>
It just happens that people have little understanding of the scope of
the Betz limit.
>
> A paddlewheel in an open flowing stream, with no change in head is limited
> in the same way (no head difference means no pressure change, and the
> density of water is unchanged). Only when a dam is built to add a
> difference in head can more power be extracted.
>
Assuming by head you mean elevation of the source, what that has to do
with wind energy is unknown to me. How can a paddlewheel have no
change in head as it moves in and out of the water? The pressure must
change for it as its elevation in the stream goes up and down. The
elevation of a dam is incidental to the principle of the force of water
turning rotors. It is the elevation of the water, among other factors,
that determines the force of water and how much power can be gained
from it.
> Your 'wind device' doesn't have a pressure difference upstream/downstream,
> and the air is not significantly change in density, so the Betz limit still
> applies.
>
>
Wrong again. The air exiting the device has lost some of its energy in
turning rotor, thus it has lower pressure coming out than it had going
in, so the Betz limit does not apply to it, by your own words.
>
> And the Betz limit is the theoretical maximum, not the actual power
> extraction.
>
True, but it only applies to airfoiled rotors.

.

Relevant Pages

  • Re: Mobile S-Rotor!
    ... lift that can be created depends on the energy in the wind that passes ... Lift is created along the length of the blade "lever", ... >> it is less than the energy used by the vehicle engine to provide 4 to ... >> 30 hp to turn its alternator. ...
    (sci.energy)
  • Re: Mobile S-Rotor!
    ... When the wind hits the blade, ... >> blade tries to move straight back. ... disconnect the alternator belt. ... the flow area widens and the pressure rises. ...
    (sci.energy)
  • Re: Mobile S-Rotor!
    ... >>> requirements from the vehicle engine to turn the alternator have always ... >> engine must supply 4000 watts to drive that alternator under full load. ... >>> that the car moves through the wind at 60 mph or that the wind moves ... > lift is created along the length of the blade. ...
    (sci.energy)
  • Re: Alternator on a turbo
    ... Eliminating the drag from the alternator, water pump, PS, and AC would still not allow a starter motors to be smaller enough to save cost. ... The starter on the 2 cylinder/4 piston diesel Ecomotor probably has to be much larger and heavier than on a conventional spark ignition 4 cylinder engine. ... maybe little difference in battery size making no difference to cost. ...
    (alt.autos.toyota)
  • Re: Mobile S-Rotor!
    ... >> requirements from the vehicle engine to turn the alternator have always ... > 80-100 amps. ... > Ok, that takes car of "puny" car and light truck alternators, how about a ... > Because of the wind turbine. ...
    (sci.energy)