>> 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
Doug,
Thanks for the URL. Quite extensive, with all the add ons. Purely from a
design point of view I favour embossing/dimpling the discs to give the
correct spacing (Say 0.030) and using strong clamp end plates. The discs
could then be quite thin and the end plates are removed from most of the
temperature. Mounted on the E shaft starting is not a problem. If the output
was even 1 HP per pound, or even per 2 pounds, it would be worthwhile as the
increased HP comes without a fuel cost. One day I may get a round tuit.
Colin Smith
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