Electrically Powered Ultralight Aircraft

On Thu, 09 Aug 2007 23:13:55 -0400, Dana M. Hague
d(dash)m(dash)hague(at)comcast(dot)net wrote in
:

On Tue, 07 Aug 2007 14:58:07 GMT, Larry Dighera
wrote:

If a 14 HP electric propulsion system weighing 46 lbs could be
constructed, apparently it would permit the use of PPGs by pilots up
to 180 lbs.

A PPG is a LOT more efficient than a powered parachute (PPC), but
still far less efficient than a rigid wing. Still, several electric
PPG's have been flown. The primary goal here is noise and vibration
reduction, a worthy goal when the engine is strapped to the pilot's
back.

The major problem is the weight of the batteries, still far heavier
than gasoline. Also the lithium polymer batteries used are still
quite expensive (over $10,000 for enough for a half hour flight) and
somewhat dangerous (sort them out and they can explode!)

-Dana

That's interesting information. Thank you.


It sounds like you have quite a bit of experience in this area. Are
you able to provide links to any forums or web sites related to this
topic?

Are
you able to provide links to any forums or web sites related to this


Check this out: http://www.calcars.org/news-archive.html

David Johnson

On Fri, 10 Aug 2007 17:12:09 GMT, Larry Dighera
wrote:

It sounds like you have quite a bit of experience in this area. Are
you able to provide links to any forums or web sites related to this
topic?

Try http://electricppg.com

I've been flying PPG for about 6 years now; got into it when I
realized I couldn't afford to restore my Taylorcraft. Finally managed
to get another plane (Kolb this time), but PPG is so much fun I don't
intend to give it up.

Never flew an electric PPG, though... they're still pretty rare birds.

-Dana
--
--
If replying by email, please make the obvious changes.
-------------------------------------------------------------------------------
Abandon all hope, ye who PRESS ENTER here.

A technology I have not seen even mentioned in this
lengthy (but very good) thread is that of carbon nonotube
enhanced ultracapacitors, which have the promise of
the energy density of the latest lithium polymers,
but almost infinite discharge cycles and can be recharged
in seconds. What would make a whole heap of sense (to
me at least), would to develop an electric tow plane
based around this technology. Quiet, efficient, hardly
affected by density altitude, quick as refueling with
avgas when charges are needed, etc. This would get
our fleet of non-powered aircraft off the ground just
fine, without angering the encroaching land developments
and such. An efficient/viable electric towplane, that's
what we need. I'm sure other developments would stem
from it too of course.
Hats off to all people/groups considering alternatives
at this point, and down with the naysayers!
Paul Hanson


At 23:24 09 August 2007, Maxwell wrote:

'Larry Dighera' wrote in message
.. .

I would think that would be close to the bare minimum.
I flew a fixed wing
hang glider on 10 HP for a while back in the 70s. A
Manta Fledgling, and
it
was very underpowered. Maybe 100 fpm climb or so.


I would guess the rigid wing would have a higher L/D
than a powered
parachute's 4:1, so it might require less power.
Does that sound
correct in your experience?

Indeed, quite a bit less from my experience. I think
my Fledge was supposed
to be around 10:1.



"Do the usual, unusually well"--Len Niemi

There are electric winches that can launch a glider to 2000' AGL - it takes
about 1KWh. From that, I would expect that an electric tug would require
more than 5 KWh to do the same job since it is launching both the glider and
itself and must have reserve power to return for landing.

A problem for both the electric winch and this hypothetical tug is the
availability suitable power on the flight line. To recharge in a reasonable
time, you are going to need serious power service - maybe 440V 3-phase 200
amp service. That's not trivial to work with.

It's sort of like a neighbor of mine who was complaining about the price of
gas - his SUV only gets 12MPG. I suggested he think about pushing his 6000
pound truck 12 miles by hand. That would give him the proper respect for
the energy in a gallon of gasoline - and its value.

Liquid petroleum fuels are extremely energy dense. It's going to be really
hard to replace that with electricity. But maybe not impossible.

Bill Daniels


"Paul Hanson" wrote in message
...
A technology I have not seen even mentioned in this
lengthy (but very good) thread is that of carbon nonotube
enhanced ultracapacitors, which have the promise of
the energy density of the latest lithium polymers,
but almost infinite discharge cycles and can be recharged
in seconds. What would make a whole heap of sense (to
me at least), would to develop an electric tow plane
based around this technology. Quiet, efficient, hardly
affected by density altitude, quick as refueling with
avgas when charges are needed, etc. This would get
our fleet of non-powered aircraft off the ground just
fine, without angering the encroaching land developments
and such. An efficient/viable electric towplane, that's
what we need. I'm sure other developments would stem
from it too of course.
Hats off to all people/groups considering alternatives
at this point, and down with the naysayers!
Paul Hanson


At 23:24 09 August 2007, Maxwell wrote:

'Larry Dighera' wrote in message
. ..

I would think that would be close to the bare minimum.
I flew a fixed wing
hang glider on 10 HP for a while back in the 70s. A
Manta Fledgling, and
it
was very underpowered. Maybe 100 fpm climb or so.


I would guess the rigid wing would have a higher L/D
than a powered
parachute's 4:1, so it might require less power.
Does that sound
correct in your experience?

Indeed, quite a bit less from my experience. I think
my Fledge was supposed
to be around 10:1.



"Do the usual, unusually well"--Len Niemi

Bill Daniels wrote:
There are electric winches that can launch a glider to 2000' AGL - it takes
about 1KWh. From that, I would expect that an electric tug would require
more than 5 KWh to do the same job since it is launching both the glider and
itself and must have reserve power to return for landing.

A problem for both the electric winch and this hypothetical tug is the
availability suitable power on the flight line. To recharge in a reasonable
time, you are going to need serious power service - maybe 440V 3-phase 200
amp service. That's not trivial to work with.

The only electric winch I've seen specs for, the ESW2B,
http://www.startwinde.de/, solves that problem by consisting largely of
a bank of heavy duty 88 AH SLAs. These act as a buffer between the mains
supply and the winch motor, a 200 kW unit. This buffer allows continuous
launching off a (typically) 12 Kw mains supply. Stated power supply
requirement is anything between 7 and 20 kW, which probably reflects the
average launch rate throughout the day. 12kW is still around 30 amps:
not trivial, but a lot easier to deal with than 200.

Of course, its still expensive to put in buried cables to the winch
positions, but as an interim measure I should think that the winch could
be driven off a trailer mounted generator.

For example, we use five winch positions on our field, but almost all
launching is done from two of them. The fifth is almost never used. The
two most common positions and one of the 2nd tier positions could be
serviced from two power cables and it would make economic sense to
purchase a used trailer generator to cover the other two.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Aug 10, 3:14 pm, Martin Gregorie
wrote:
The only electric winch I've seen specs for, the ESW2B,http://www.startwinde.de/, solves that problem by consisting largely of
a bank of heavy duty 88 AH SLAs. These act as a buffer between the mains
supply and the winch motor, a 200 kW unit.

I know of a winch in Denmark which is diesel-electric. It sits on an
old Scania truck whose engine is connected to an alternator, and the
alternator to the winch motor, all under (reasonably simple) computer
control. It's self-contained, but gives smooth, powerful, controlled
and repeatable launches. IMO it's probably the best winch design from
a technical stand point. However it's much more expensive than a
normal big V8/truck axle winch, and it's not clear that the benefits
outweigh the costs.


Dan

It's sort of like a neighbor of mine who was complaining
about the price
of
gas - his SUV only gets 12MPG. I suggested he think
about pushing his
6000
pound truck 12 miles by hand. That would give him
the proper respect
for
the energy in a gallon of gasoline - and its value.

Liquid petroleum fuels are extremely energy dense.
It's going to be
really
hard to replace that with electricity. But maybe not
impossible.

Bill Daniels
For many applications a better 'alternative energy'
might be to squeeze
the maximum available power out of existing technology.
Below is an
engine which uses the heat from combustion to add another
power stroke
to an engine. Its not electrically powered but in
the future it may
compete with electric engines.
http://www.popsci.com/popsci/technology/
c1609351d9092110vgnvcm1000004eecbccdrcrd.html

Name: Steam-o-Lene Engine
Inventor: Bruce Crower
Cost to Develop: $1,000
Time: 1.5 years
Prototype | | | | | Product


Bruce Crower's Southern California auto-racing parts
shop is a temple for
racecar mechanics. Here's the flat eight-cylinder Indycar
engine that won
him the 1977 Louis Schwitzer Award for racecar design.
There's the
Mercedes five-cylinder engine he converted into a squealing

supercharged two-stroke, just 'to see what it would
sound like,' says the
now half-deaf 77-year-old self-taught engineer.

Crower has spent a lifetime eking more power out of
every drop of fuel
to make cars go faster. Now he's using the same approach
to make them
go farther, with a radical six-stroke engine that tops
off the familiar
four-stroke internal-combustion process with two extra
strokes of old-
fashioned steam power.

A typical engine wastes three quarters of its energy
as heat. Crower's
prototype, the single-cylinder diesel eight-horsepower
Steam-o-Lene
engine, uses that heat to make steam and recapture
some of the lost
energy. It runs like a conventional four-stroke combustion
engine
through each of the typical up-and-down movements of
the piston
(intake, compression, power or combustion, exhaust).
But just as the
engine finishes its fourth stroke, water squirts into
the cylinder, hitting
surfaces as hot as 1,500°F. The water immediately evaporates
into
steam, generating a 1,600-fold expansion in volume
and driving the
piston down to create an additional power stroke. The
upward sixth
stroke exhausts the steam to a condenser, where it
is recycled into
injection water.

Crower calculates that the Steam-o-Lene boosts the
work it gets from a
gallon of gas by 40 percent over conventional engines.
Diesels, which are
already more efficient, might get another 5 percent.
And his engine does
it with hardware that already exists, so there's no
waiting for
technologies to mature, as with electric cars or fuel
cells.

'Crower is an innovator who tries new ideas based on
his experience and
gut instincts,' says John Coletti, the retired head
of Ford's SVT high-
performance group. 'Most people won't try something
new for fear of
failure, but he is driven by a need to succeed.' And
he just might.
Crower has been keeping the details of his system quiet,
waiting for a
response to his patent application. When he gets it,
he'll pass off the
development process to a larger company that can run
with it, full-
steam.

Warning: A boring essay on obsolete internal combustion technology follows.

A merging of steam and internal combustion is probably the first "hybrid"
with the first efforts dating from the beginning of the last century. The
pinacle of its development was the monster water-injected turbo-compound
radial engines developed late in WWII.

Water injection acts is several favorable ways. First, somewhat as
described below, it flashes into steam to increase the cylinder pressure and
then escapes through the exhaust valves to a pressure recovery turbine which
transmits its power back to the crankshaft through a fluid coupling - the
"turbo compound" part.

Water also cools the cylinder allowing more fuel/air mixtue to be forced
into it. Finally, and this not widely known, water is even more effective
than tetraethyl lead in decreasing the tendency of the fuel/air mixture to
detonate or pre-ignite thus allowing far higher boost pressures. The only
compound more effective than water is nitros oxide.

Both Allied and Axis ari forces used water injection but only Germany used
nitros oxide. Either could double an engines power for as long as the
supply of H2O or NO lasted. But, on a power to weight basis, avgas easily
wins so water injection was only used for takeoff or when maximum military
power was needed to escape an enemy.

The citation for the above is a very old engineering textbook titled "High
Speed Internal Combustion Engines" by Sir Harry Recardo. I highly recomend
it if you are at all interested in IC engines. Sir Harry's work on sleeve
valve engines is particularly interesting.

I could be wrong but I would guess that water injection gets 90% of the
benifits possible without the major modification to the engine required by
Bruce Crower's "6-stroke".

Bill Daniels


"Steve Davis" wrote in message
...
It's sort of like a neighbor of mine who was complaining
about the price
of
gas - his SUV only gets 12MPG. I suggested he think
about pushing his
6000
pound truck 12 miles by hand. That would give him
the proper respect
for
the energy in a gallon of gasoline - and its value.

Liquid petroleum fuels are extremely energy dense.
It's going to be
really
hard to replace that with electricity. But maybe not
impossible.

Bill Daniels
For many applications a better 'alternative energy'
might be to squeeze
the maximum available power out of existing technology.
Below is an
engine which uses the heat from combustion to add another
power stroke
to an engine. Its not electrically powered but in
the future it may
compete with electric engines.
http://www.popsci.com/popsci/technology/
c1609351d9092110vgnvcm1000004eecbccdrcrd.html

Name: Steam-o-Lene Engine
Inventor: Bruce Crower
Cost to Develop: $1,000
Time: 1.5 years
Prototype | | | | | Product


Bruce Crower's Southern California auto-racing parts
shop is a temple for
racecar mechanics. Here's the flat eight-cylinder Indycar
engine that won
him the 1977 Louis Schwitzer Award for racecar design.
There's the
Mercedes five-cylinder engine he converted into a squealing

supercharged two-stroke, just 'to see what it would
sound like,' says the
now half-deaf 77-year-old self-taught engineer.

Crower has spent a lifetime eking more power out of
every drop of fuel
to make cars go faster. Now he's using the same approach
to make them
go farther, with a radical six-stroke engine that tops
off the familiar
four-stroke internal-combustion process with two extra
strokes of old-
fashioned steam power.

A typical engine wastes three quarters of its energy
as heat. Crower's
prototype, the single-cylinder diesel eight-horsepower
Steam-o-Lene
engine, uses that heat to make steam and recapture
some of the lost
energy. It runs like a conventional four-stroke combustion
engine
through each of the typical up-and-down movements of
the piston
(intake, compression, power or combustion, exhaust).
But just as the
engine finishes its fourth stroke, water squirts into
the cylinder, hitting
surfaces as hot as 1,500°F. The water immediately evaporates
into
steam, generating a 1,600-fold expansion in volume
and driving the
piston down to create an additional power stroke. The
upward sixth
stroke exhausts the steam to a condenser, where it
is recycled into
injection water.

Crower calculates that the Steam-o-Lene boosts the
work it gets from a
gallon of gas by 40 percent over conventional engines.
Diesels, which are
already more efficient, might get another 5 percent.
And his engine does
it with hardware that already exists, so there's no
waiting for
technologies to mature, as with electric cars or fuel
cells.

'Crower is an innovator who tries new ideas based on
his experience and
gut instincts,' says John Coletti, the retired head
of Ford's SVT high-
performance group. 'Most people won't try something
new for fear of
failure, but he is driven by a need to succeed.' And
he just might.
Crower has been keeping the details of his system quiet,
waiting for a
response to his patent application. When he gets it,
he'll pass off the
development process to a larger company that can run
with it, full-
steam.

On Aug 13, 8:10 pm, "Bill Daniels" bildan@comcast-dot-net wrote:
Warning: A boring essay on obsolete internal combustion technology follows.

A merging of steam and internal combustion is probably the first "hybrid"
with the first efforts dating from the beginning of the last century. The
pinacle of its development was the monster water-injected turbo-compound
radial engines developed late in WWII.

Water injection acts is several favorable ways. First, somewhat as
described below, it flashes into steam to increase the cylinder pressure and
then escapes through the exhaust valves to a pressure recovery turbine which
transmits its power back to the crankshaft through a fluid coupling - the
"turbo compound" part.

Water also cools the cylinder allowing more fuel/air mixtue to be forced
into it. Finally, and this not widely known, water is even more effective
than tetraethyl lead in decreasing the tendency of the fuel/air mixture to
detonate or pre-ignite thus allowing far higher boost pressures. The only
compound more effective than water is nitros oxide.

Both Allied and Axis ari forces used water injection but only Germany used
nitros oxide. Either could double an engines power for as long as the
supply of H2O or NO lasted. But, on a power to weight basis, avgas easily
wins so water injection was only used for takeoff or when maximum military
power was needed to escape an enemy.

The citation for the above is a very old engineering textbook titled "High
Speed Internal Combustion Engines" by Sir Harry Recardo. I highly recomend
it if you are at all interested in IC engines. Sir Harry's work on sleeve
valve engines is particularly interesting.

I could be wrong but I would guess that water injection gets 90% of the
benifits possible without the major modification to the engine required by
Bruce Crower's "6-stroke".

Bill Daniels

"Steve Davis" wrote in message

...



It's sort of like a neighbor of mine who was complaining
about the price
of
gas - his SUV only gets 12MPG. I suggested he think
about pushing his
6000
pound truck 12 miles by hand. That would give him
the proper respect
for
the energy in a gallon of gasoline - and its value.

Liquid petroleum fuels are extremely energy dense.
It's going to be
really
hard to replace that with electricity. But maybe not
impossible.

Bill Daniels
For many applications a better 'alternative energy'
might be to squeeze
the maximum available power out of existing technology.
Below is an
engine which uses the heat from combustion to add another
power stroke
to an engine. Its not electrically powered but in
the future it may
compete with electric engines.
http://www.popsci.com/popsci/technology/
c1609351d9092110vgnvcm1000004eecbccdrcrd.html

Name: Steam-o-Lene Engine
Inventor: Bruce Crower
Cost to Develop: $1,000
Time: 1.5 years
Prototype | | | | | Product

Bruce Crower's Southern California auto-racing parts
shop is a temple for
racecar mechanics. Here's the flat eight-cylinder Indycar
engine that won
him the 1977 Louis Schwitzer Award for racecar design.
There's the
Mercedes five-cylinder engine he converted into a squealing

supercharged two-stroke, just 'to see what it would
sound like,' says the
now half-deaf 77-year-old self-taught engineer.

Crower has spent a lifetime eking more power out of
every drop of fuel
to make cars go faster. Now he's using the same approach
to make them
go farther, with a radical six-stroke engine that tops
off the familiar
four-stroke internal-combustion process with two extra
strokes of old-
fashioned steam power.

A typical engine wastes three quarters of its energy
as heat. Crower's
prototype, the single-cylinder diesel eight-horsepower
Steam-o-Lene
engine, uses that heat to make steam and recapture
some of the lost
energy. It runs like a conventional four-stroke combustion
engine
through each of the typical up-and-down movements of
the piston
(intake, compression, power or combustion, exhaust).
But just as the
engine finishes its fourth stroke, water squirts into
the cylinder, hitting
surfaces as hot as 1,500°F. The water immediately evaporates
into
steam, generating a 1,600-fold expansion in volume
and driving the
piston down to create an additional power stroke. The
upward sixth
stroke exhausts the steam to a condenser, where it
is recycled into
injection water.

Crower calculates that the Steam-o-Lene boosts the
work it gets from a
gallon of gas by 40 percent over conventional engines.
Diesels, which are
already more efficient, might get another 5 percent.
And his engine does
it with hardware that already exists, so there's no
waiting for
technologies to mature, as with electric cars or fuel
cells.

'Crower is an innovator who tries new ideas based on
his experience and
gut instincts,' says John Coletti, the retired head
of Ford's SVT high-
performance group. 'Most people won't try something
new for fear of
failure, but he is driven by a need to succeed.' And
he just might.
Crower has been keeping the details of his system quiet,
waiting for a
response to his patent application. When he gets it,
he'll pass off the
development process to a larger company that can run
with it, full-
steam.- Hide quoted text -

- Show quoted text -

The reference in Sir Harry Recardo's book to doubling HP with water
injection and Nitrous Oxide could lead someone to believe that those
two ingredients were all that was needed.

There is no advantage to injecting water into a conventional normally
aspirated 4-stroke IC engine although an endless array of systems to
do so has been sold to the unwary. Water or water/alcohol injection
however has long been known to do an excellent job of reducing
combustion temperatures thereby preventing detonation. While this is
of little importance in a normally aspirated engine it is a big help
in forced induction engines. I have used both water and water/alcohol
in two turbocharged motorcycle engines over a 15-year period with very
good results. Dyno results have not shown any measurable added HP from
the water alone (possibly because the water displaces some air/fuel
mixture) but it allows a significant increase in boost pressure, which
can add a bunch. Any engine dependent on this scheme for detonation
protection will however self-destruct in short order should the water
flow stop.

Nitrous Oxide injection provides more oxygen, which in turn allows
more fuel to be added which is the source of the extra HP.

Crower's Steam-o-Lene is another matter. Think I'll wait until they go
into mass production. It must have an interesting exhaust sound.