Paul,
Yes this picture of axial impulse turbine picture is what got me jazzed
about T.C. in the first place. How to isolate the heat from the end housing
and gearbox would be a challenge. We are talking over 1650 degrees here
right? Put on the other end, isolated, with double walled housing
and water cooled shaft it might be doable. Space might then be the
problem.
Hence we start testing with a less efficient but more compact centrifugal
turbine. Perhaps as Matt suggested once we have some data we can
order up a smaller axial turbine.
Reeves,
I did save your 10/2004 note but missed the significance of it.
Thanks for re-sending it. I am curious as to your thoughts if the
same increase in efficiency would happen at high altitude by
engaging an Rotrex traction driven supercharger (running off of the
front engine belt) and devoting the exhaust driven turbine solely
to the function of turbo compounding?
You mention the T0-4 Garret group of turbines is good but for 300hp turbo
normalizing I believe Tom Parks is using a T0-6. Better?? In
addition my brother and other A & Ps have recommending RaJay units
as a bullet proof devices. I understand RaJay have been owned by
everyone including Garrett at one time or other. I completely agree
with you on using made-for-aviation-turbos however. In the bench
test phase cheap auto turbos can provide some serious data in the
preliminary tests.
Doug Fir
-----------------------------
Paul,
It looked interesting before, it still looks interesting maybe even more
so.
It appears it would work, how well would it work? your best guess
will do. What is the cost guesstimate of doing this ? It does appear
to have advantages at least in terms of simplicity. May be some sort
of air flow through fins between the engine and the turbine unit
would solve the possible heat issue just to try and keep it simple.
Only a thought. otherwise maybe a water barrier of some sort
connected to the cooling system via the water heater ports, yes
there is a heat impact but it should not be OTT.
Regards David
One of your countrymen Paul Carey obtained
a air cooled blade turbine from an R3350 tubo compound
radial engine. This turbine generated 300 HP when
fed from six cylinders of the 18 of the R3350. He lived in
Perth but he gave up on the project.
Paul Lamar ...No rotor no motor.
Paul,
Might be an application for a large diameter Tesla turbine direct mounted to
the front of the E shaft. No hard facts on output or efficiency, but costs
may be lower than a special impulse wheel. There appears to be some
development work on Tesla turbines at the moment, but we may have to wait for
some results.
Colin Smith
Colin,
As a Tesla fan, I looked into the multi-plate turbine quite early on and
realize that heavy weight would be one of the the challenges unless titanium
plates and housings were used.
Here is website of a someone at Standford Univ. experimenting with these
turbines now that you might enjoy. There was some mention of a free
software download modeling fluid dynamics of the turbine that Paul could no
doubt appreciate.
<http://www.stanford.edu/~hydrobay/lookat/tt.html#sect-1>
As you no doubt know, for the Tesla turbine design to handle the volume of
exhaust gas flow from a boosted 13B there would have to be a significant
amount of plates and perhaps several nozzles inlets. Add to that a housing
and things get heavy fast.
The Tesla turbine, though hard to start, is fairly efficient at high rpm.
Since it has been around for almost 100 years it makes you wonder why people
making turbo generators like Capstone don't use it. Probably cost and size.
The many variables such as plate spacing, nozzle size, gas flow dynamics and
plate diameter make developing this turbine for aircraft turbo compounding a
significant research project all in itself.
Doug Fir
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