Paul,

I often wondered why I like those disc impeller pumps so
much.  Then it
dawned on me.  Tesla turbine.

Not happy with how my ideal TC engine was physically
forming up I
decided
to give the Tesla turbine another look.  I spent a
sleepless night
designing a true spin muffler that would be driven by the
exhaust of the
rotary engine.  Size restrictions dictate a six inch
diameter turbine
section and perhaps one for each rotor housing.  A
common shaft is do
able and puts the bearings outside the case. Most of the
components
should be made from Inconel or even titanium. Stainless 316
is good
enough for the testing.  Laser cut plates
absolutely.  At least for the
13B the Tesla turbines exhaust could exit near the
intermediate housing
and  feed a small T4 hybrid turbocharger.  Tesla
turbines are tune-able
for the desired rpm output by removing or adding discs.

Most of Tesla turbines motors out there have been running
on high
pressure air or steam simply because it is available but
hot gases are
also possible depending on the ratio of inlet to outlet
port size.
Turbine efficiencies are quote at from 40 to
95%.   The higher figure is
nonsense IMHO.  Centrifugal turbine are in their mid
50s at peak so I
suspect the lower quote is closer to ball park.  Axial
turbines are a
bit better but either of these high rpms or large diameter
turbine are a
logistic nightmare.  I have believe a T4 radial
turbine is not going to
be able to recover much more than 30hp. at speeds low
enough for a
traction drive to handle it. The mounting and connection
considerations
are also daunting.  This started to add up to
unacceptable weights.

I had orginally designed a spin muffler around a central
pipe punched
with bypass exhaust holes and a  with the
planned  turbine to be mounted
outside on the muffler case. Making the spin muffler
literally spin
saves space perhaps development time.  It it saves me
from having to use
a supercharger so much the better.

  I can see a few points that may increase the Tesla
turbine efficiency.
New spacing methods to lower windage,  texturing the
discs, and
eliminating skin drag loss on the outer end housings. If nothing else
it would make a heck of  a quiet
muffler.   Injecting air into the
exhaust nozzles would help contribute to a complete burn
and increase
inlet pressure.

Putting the turbocharger on the outlet of the Tesla's spin
muffler would
subject it  to lower temperatures.  Will it
work?  Who knows but at
least this is something I can build and test.

Anybody else have some thoughts on design feel free to
chirp in.
Depending how it mounted it could feed the power to the
accessory side
or the PSRU side of the engine with the obvious differences
in required
shaft lengths.

Now I am thinking to make a prototype with the housing made
of a six
inch
ID Inconel pipe.  Discs will be SUS316L.  2.0 mm
thick. Spacing at least
2.0 mm. Numerous discs. Both exhaust pipe rectangular and tangentially
wrapping at least 60 degrees around the outer muffler
housing.


Doug in Japan


That is interesting.  I have been thinking along the
same lines
recently.  I'm building a 14" disc prototype.  I
guess my input would be
to consider water injection as well.  I've seen posted
the thought that
spacers on the periphery don't degrade efficiency.  If
you used wafer
thin ferrite magnets you might be able to use the turbine
as your
alternator.  I'd be very interested in seeing any
formulae you may have
found in your research to calculate efficiencies, etc.
 Decker, Michael


If you'r suggesting the magnets are also exposed to the exaust stream, it's a non starter. The magnets subjected to that high a temp. would surely reach the Curie pt where the magnetic properties go to zero.
Robert