Hi Paul
i sent the mail to the manager of the research and development department
of Mazda, to mr. Hiraishi, but he didn't answered me, i think i didn't
explain well in the email i sent to you yesterday.
I copy the mail i sent him:
[Good morning, Mr. Hiraishi
My name is David, I?m from Spain and I?m studying a master?s degree about
motorsports (METCA, managed by Sergio Rinland:
srinland@epsiloneuskadi.com).
I would like to propose you the development, as my master?s final project,
of a Turbo-Compounding system applied to a Wankel engine.
I have been in contact with Paul Lamar (
rotaryeng@earthlink.net), a
retired engineer who has a great knowledge about rotary engines and he
agreed to develop this technology in this kind of engines because of the
characteristics of the exhaust system, so the efficiency and power would be
increased.
I would like to know if you are developing this technology, so I could help
you in anything you could need (moving to your facilities if necessary), or
if you are interested in this Turbo-Compounding technology, but you arenot
working on it, I could develop it with your help (in the facilities of the
master?s degree i?m doing), asking you for some data when needed.
Anyway, if you are not interesting in this development, could you please
provide me a contact in Mazda Japan, so i could propose them this idea
Thank you for your attention,
Looking forward to hearing from you,]
2011/7/28 Rotary Engine <
rotaryeng@earthlink.net
Hello Paul,
My name is David, I am from Spain and I'm doing a master's degree about
motorsports in Epsilon Euskadi's facilities (METCA, that is managed by
Sergio
Rinland).
I have been reading your website and i find very interesting the Turbo
Compounding in order to improve the engine performance and efficiency,
that's why i would like to do the master's project about it.
Sergio Rinland suggested me to get in contact with you in order to find
an
automotive company which is developing it, so i could help them in that
developing work.
I have seen that the Turbo Compounding could be applied as it is in the
examples you show in your website, to transmit the turbines torque to the
crankshaft of the engine, but also, i think it could be interesting to
use
it as a "battery charger" for a hybrid car.
I hope you can help me, because i think this is a very interesting
project
that could help the automotive industry in the nearest future.
I look forward to hearing from you,
Kind Regards
David Garcia
Yes I know Sergio Rinland. I met him at the World Motorsport Symposium in
Oxford. It can be used as a battery charger but perhaps that is not the
best way to use it. Each time one converts energy from one form to
another
there are some losses. These losses rapidly multiply. If a generator is
90% efficient and a motor is 90% the over all efficiency becomes only 81%.
Ultimately a car requires mechanical energy to move.
The first thing one
must do with a turbo compound is to convert the momentum and heat energy
in
the exhaust to mechanical energy. It is best to use that mechanical
energy
directly to move the car for the reasons stated above. Turbo compound
truck
engines are rapidly becoming the norm. Turbo compound ship engines
frequently utilize the waste energy in the exhaust to generate electricity
for use on the ship. Large gas turbine power plants use the exhaust
energy
to generate steam for steam turbines which increases the overall plant
efficiency to over 50%. These are called "combined cycle" or "bottoming
cycle" power plants.
A typical car engine is less than 35% so herein lies
the opportunity to drastically reduce the world wide consumption of hydro
carbon fuels. The piston car engine loses 20% of the energy in the
exhaust
to aerodynamic and heating losses on the exhaust valve. Of course over
50%
of the energy in the fuel burned in the IC is lost to the exhaust. The
Wankel rotary by comparison is "piston ported" so to speak so these
exhaust
valve loses are drastically reduced. It has no exhaust valves. It is
true
the current Wankel rotary design is 5 to 10% less efficient than the
current
piston engine but it still remains the best choice for high power to
weight
ratio turbo compound engine used to power both airplanes and cars.
The turbo compound Wankel rotary would become the most efficient internal
combustion engine suitable for vehicles. Engine weight is a key factorin
the overall empty weight of both airplanes and cars. A lighter vehicleis
a
more efficient vehicle.
The aircraft and recreational boat application of the turbo compound
rotary is
trivial from an engineering point of view while the real challenge is the
wide
dynamic range of the passenger vehicle engine.
Paul Lamar
Hello Paul;
So, as I was wondering, having in account the losses of converting the
mechanical energy to electrical energy it's a better idea to use the
mechanical energy of the turbine directly.
You think it is a good idea to apply this technology to passenger vehicle
engines. Do you know if any automotive company developing it so I could
get in contact with them and try to collaborate in that developing
process?
In case I could not get in contact with any company I would like to
develop
it on my own, but I don't know if you could help me with my doubts during
the developing process. I don't have too much experience on this yet.
Thank you very much,
Kind regards
David Garcia
Using the mechanical energy directly means one does not have to carry
the extra weight of a battery, generator and electric motor. Also there
is a world wide limited supply of lithium for advanced batteries.
The best approach to the problem is use two engines. One small one
for cruise on the autobahn and a larger one for acceleration and
hill climbing. As you can see from this chart the optimized BSFC
island of a large engine is too far, in terms of throttle opening
(manifold pressure) and RPM, from constant speed flat road
load requirements. This has been mitigated somewhat in modern cars
by using a lower reduction ratio (lower cruise RPM) in top gear.
Most of the improvement in MPG has come from this practice despite
large weight increases due to government crash requirements.
This dual engine idea can and has been implemented by partially shutting
down a few cylinders in multi cyclinder piston engines. One good way of
doing this is allow the exhaust or intake valve to remain open or closed
while that
cylinder is not needed. Since the piston is still going up and down there
are still pumping and friction losses from the shut down cylinders.
The Wankel on the other hand is unique in the fact the straight eccentric
shaft can be made concentric with a smaller interior shaft. That would
allow the larger engine to be completely shut down.
The Wankel also has the turbo compound advantage of no exhaust valve to
reduce
the energy in the exhaust stream so it is ideal for the turbo compound
configuration. NASA studied the Wankel turbo compound engine in this
technical paper:
http://www.rotaryeng.net/NASA-**Paper-turbo-compound-rotary.**pdf<
http://www.rotaryeng.net/NASA-Paper-turbo-compound-rotary.pdf
NASA concluded it was possible to recover 80 free HP from a
Mazda sized rotary engine with minimal increase in fuel burn.
Unfortunately NASA ran out of money before this could
be tested in hardware.
Here is a design that implements this dual Wankel engine approach. Small
and large Wankel engines are available off the shelf to build a prototype
for testing. The small engine would be turbo compounded to lower the
fuel burn for the 95% of the time the car is in cruise mode.
http://www.rotaryeng.net/RX8.
http://www.rotaryeng.net/RX8-TC-eng3.html
So far to my knowledge no car company is working on this turbo compound
idea. Mazda is ideally positioned to do this so you might try
contacting Mazda.
I will be glad to help including a trip or two to Spain
if necessary at my expense.
Paul Lamar
Hello Paul,
As i told you, i put in contact with some people from Mazda and also from
AER engines, a company that works for Mazda.
They told me that they can't help me because their projects depend on
their
customers, and nowadays they don't have any about turbo-compounding, soi
think that i will have to develop this project on my own, with your help,
of course.
I have been thinking about how can i start it, and i don't know yet how
can
i structure the process. I have a clear idea, i will use the design of an
ordinary turbocharger, where i can adapt the gearbox and all the thingsi
need for the design.
I guess that the best engine to adapt the Turbo-Compunding is the 1.3
liters
engine of the RX8, what do you think? in case of using this engine, do you
know what kind of turbo is the most common used in this rotary engine? i
will look for information of it and i will try to start the 3D design of
it.
when i decide what engine i will use, i will need some information about
the
exhaust gases, such as speed and temperature, so i will be able to
simulate
the turbine runing, obtaining the speed of it. do you have that kind
of information?, or do you know where i can find it?
Thank you for your attention!
Kind regards,
David Garcia
That is like Mazda saying they are not interested in better gas mileage:)
I think you have a communication problem David.
Whom did you contact at Mazda?
Email me your letters David and I will take a look.
I am not surprised about Advanced Engine Research (AER) in the UK as they
do only custom turbo charged 2 liter 4 cylinder piston engines for Mazda
through Dyson racing. They are not that competant as the best they have
accomplished so far is a 3rd in LMP2 class at Le mans in 2009.
http://www.aerltd.com/
IMHO it is a misguided attempt by Mazda to put their stock mediocre 4 cyl
piston engine on the world wide racing scene. Better and much larger
companies than AER build better racing piston engines and spend ten times
more money doing it. Renault, Ferrari and Mercedes Benz for examples. IMHO
Mazda would be better off putting the money into their unique Wankel rotary
to improve the efficiency.
The rotary has put Mazda on the world racing map since the early 1970's
culminating with an over all outright win at Le Mans in 1991. Not their
piston engines with the exception of SCCA Miata spec. Sometimes I think
Mazda forgets that fact. Without the rotary, Mazda will always be second
rate to Toyota, Honda and Korean car manufactures that generally do a better
overall job of building cars. Understandably so because they are ten times
larger.
IMHO Mazda needs to try harder on the rotary.
Paul Lamar
--
Hello Paul
I have just finished my holidays and i am going to start this project.
I would need your help because i don't even know where to start and i have
only two or three months (luckily) to do it. If you think that with your
help i can do a good project i will go forward, because i think it is and
interesting project instead i don't have to much experience and knowledge.
I look forward to hear from you as soon as possible,
Thank you Paul
-- David Garcia
Plenty of papeer studies have been done on TC Wankel rotaries.
It is time to build the hardware and test it. That will take
many months depending on your machine shop resources.
Paul Lamar
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