Part of this article I apologize for.  It is as if the writers are
totally unaware of turbo-compounding.

Nevertheless, I supply this article because it might suggest a way
we can deal with the supersonic, 1700 degree F. pulses of exhaust
blasting out of our rotary engines.  Could we append thermoelectric
devices somehow in the exhaust stream to take away some heat--the
waste part of the exhaust, the part that the turbocompounder cannot
recycle?  Could the thermoelectric devices turn the heat into
electricity, and feed the power back into powering the aircraft?

We would also use a turbocompounder, which would pick up even more
exhaust energy, to channel the energy it can reclaim into powering
the plane.

Could we see 70% efficiency? (DREAM, DREAM, DREAM!:-)

Here is part of the article:

"Researchers Try to Convert Car's Exhaust Into Power
"Tuesday, August 12, 2008
"Associated Press

"Researchers are competing to meet a challenge from the U.S.
Department of Energy: Improve fuel economy 10 percent by converting
wasted exhaust heat into energy that can help power the vehicle

"Their research into thermoelectrics the science of using
temperature differences to create electricity . . .

"GM researcher Jihui Yang said a metal-plated device that surrounds
an exhaust pipe could increase fuel economy in a Chevrolet Suburban
by about 5 percent, a 1-mile-per-gallon improvement that would be
even greater in a smaller vehicle.

"Three teams were selected to participate in the program, with GM
and thermoelectrics manufacturer BSST separately working on cars and
a team from Michigan State University focusing on heavy-duty trucks.

"Fairbanks said thermoelectric generators should be on the verge of
production in about three years.

"'It's probably the biggest impact in the shortest time that I can
think of,' he said.

"The technology is similar to what NASA uses to power deep space
probes, a perk being it doesn't seem to be susceptible to wear.
Probes have used a thermoelectric setup for about 30 years.

"Thermoelectric devices can work in two ways using electricity to
provide heating or cooling, or using temperature differences to
create electricity.
"The second method is Yang's focus, and for good reason.

"In an internal combustion engine, only about a quarter of the total
energy from gasoline is used to actually turn the wheels, while 40
percent is lost in exhaust heat and 30 percent is lost through
cooling the engine.

"That means about 70 percent of the available energy is wasted,
according to GM.

"'If I can use some of that heat energy and convert it to
electricity, you can improve the overall efficiency,' Yang said.

"A Suburban produces 15 kilowatts of exhaust heat energy during city
driving, which is enough to power three or four air conditioners
simultaneously.

"But it's not possible to harness all the exhaust heat a vehicle
produces, so when the Suburban is cruising between 50 and 60 mph,
the generator can produce about 800 watts of power, Yang said.

"That electricity could go to accessories such as a GPS device, DVD
player, radio and possibly the vehicle's water pumps.

"Yang's prototype device is to be tested in a Suburban next year. A
similar prototype created by Ohio State scientists and BSST should
be tested in a BMW in 2009.

"The thermoelectric generator works when one side of its metallic
material is heated, and excited electrons move to the cold side. The
movement creates a current, which electrodes collect and convert to
electricity."

Les Nordman :-)

--------------------------------------------------------------------
---- Thanks Les.

We talked about this thermo pile or ganged thermal couples around
the exhaust pipe years ago but so far I have not found the very
first message. I did find this one back in Dec 2006. I am still
looking.

Paul Lamar

-------- Original Message --------
Subject: Diesel turbo charger turbine & compressor power
Date: Sat, 30 Dec 2006 20:46:58 -0800
From: Rotary Engine <rotaryeng@earthlink.net>
To: AARotary Engine <rotaryeng@earthlink.net>


Well the exhaust energy is a bit higher for the rotary than it is
for a piston engine but only about 5% or so more. Say 50% rather
than 45%. The big difference is two thirds of the exhaust energy
is dissipated by the exhaust valves in a piston engine. All engines
have a heat balance where the percentages of the energy in a gallon
of gas is distributed to various systems in the engine.
I assume you have read  http://www.rotaryeng.net/turbo.html

Building a turbo compound yourself is very expensive. I have
spent $7,000 on the project so far but I have a few contacts
in the aerospace biz and they tell me a large company is working
on it for small UAV rotary engines. Plenty of tech papers have
been written on the rotary turbo compound. Mostly computer
simulations. Most are very positive. So far no rotary based hardware
has been built to my knowledge yet.

I am waiting  until I get more info from that source
as it will save me doing a lot of very expensive R&D. Hopefully it
will not be classified.  If developed for the worlds cars a
theoretical 20% in fuel consumption world wide is possible. If you
can't wait and want to try it yourself I will give you all the help
I can including loaning you my $7,000 turbo charger gear box.

The technology is 70 years old so it should not be all that
hard. Yes you can cool the exhaust but in theory that wastes
some of the energy in the exhaust. Better to deal with the
heat. One way is use a thermo pile ahead of the exhaust turbine
to extract some of the heat as electrical power and cool the exhaust
a bit. http://www.harvestfields.ca/etextLinks/16/05.htm


Paul Lamar ...No rotor no motor.

Hi All-

My idea Re:  - thermocouples on the zorst - was to provide enough power
to feed an emergency battery for Radios , Avionics and ( especially
with the CMOS version of the 555 ) EFI. Any  takers ? I understand
some rockets use these to power the electronics , IIRC by charging up
a lithium battery. The arming circuits in nuclear warheads have also
been cited using the above method :^/

Fly & build good - Bryan