> The box is in the NC machine shop.
    > Should be done when I get back from Sun & Fun.
    > Next step is build up a turbo II engine and test it on the
    > dyno.
    >
    > Here are a few 3D's of the traction drive parts and final
    > drive.
    >
    > I may give an AIAA paper on the subject on May 13 in Anaheim Ca.
    >
    > Paul Lamar ...No rotor no motor.

   -----------------------------------------

   How does the traction drive unit function? Which parts rub
   together to make the traction?
   Tim

   ----------------------------------

   In the first 3D the small shaft rubs on the three brown
   rollers which in turn rub on the outer ring.
   The outer ring is undersized to apply pressure on the
   rollers and the small input shaft forming a planetary
   reduction unit.

   ----------------------------------------
   As I was preparing for my forum at the Sun n Fun air show in
   Lakeland Fl. I had an idea on how best to represent the problem
   of using an automotive turbo charger in an aircraft engine.
   Automotive turbo chargers are  designed to spool up as quickly
   as possible. This means the turbine is over sized to accelerate
   themselves and the compressor (hence the boost) as fast as possible
   for good car acceleration reasons.

   This choice of turbine is bad for a simple turbo charged air craft
   engine  as it leads to turbocharger over speed and turbine failure as
   can be seen from this chart. It is good if you plan to
   turbo compound the Wankel rotary aircraft engine. The exact
   load on the turbine represented by the curved line on the right
   is a guess and will vary with the compressor section chosen
   by the car manufacturer. In this case Mazda.

   Evidence for the truth of the matter is the fact that at
   least three Mazda stock turbo charger turbines have been destroyed
   so far by aircraft installation. I suspect it is not so
   much the high temperature of the rotary exhaust as it is
   by the over speeding of the turbo charger.

   The centrifugal loads  on the turbine blades are enormous
   at 90,000 to 120,000 RPM.

   More evidence is available by merely installing a larger
   compressor section thereby loading down and slowing down
   the RPM of the turbo charger which seems to increase the life
   of the turbine. There is no loss in max constant speed boost
   available.  This is what Dave Leonard did successfully.

   The chart shows this situation. Gas turbines have max torque
   at zero RPM with a straight line drop to zero as the blades
   of the turbine reach the same speed as the gas exiting
   or squirting out of the nozzle. The torque is given in foot
   pounds on the right vertical axis. In this case the gas speed
   is assumed to be constant and the combination of gas speed,
   blade diameter and area are set to generate a max HP of 50.
   The formula, HP = T x RPM / 5250, was used to plot the max HP
   of the turbine as a function of RPM. The compressor load
   curve is off to the right to insure there is excessive HP to
   accelerate the turbo charger way beyond what is necessary
   to generate the boost if the turbo charger was running
   at a constant RPM.

   The 50 HP number was chosen as a possible number for
   extracting the kinetic energy in the 309 waste HP in the
   exhaust of a 200 net HP Mazda rotary engine. I also modified
   a Mazda chart by adding HP numbers to the right of the percentages
   shown in the second chart to show this relationship. 50 HP
   represents a recovery of only 17% of the total heat energy in the
   exhaust of a 200 HP rotary engine. 50 HP is also near the
   middle of the NASA study range of predicted potential HP in
   the rotary engine that they studied.

   Given the turbo compound
   engine picks up 50 additional HP for no increase in fuel burn
   or cooling load the BSFC drops from .46 to .37!!! Right
   down there with the best diesel engines and without the
   diesel engine weight penalty. This also correlates with
   what was obtained 60 years ago by Curtis Wright with
   the R3350 TC airliner engine.

   Needless to say this bodes well for our attempt to extract some
   of this waste energy and put it to use to reduce the fuel
   burn.

   The last picture is of the turbine in a stock 1988 Mazda Turbo
   II engine.

   Paul Lamar ...No rotor no motor.


Would it be feasible/worthwhile to build a dyno just for the exhaust
turbine?  Maybe you could do it without any reduction box.


Matt-

Perhaps with a friction disc brake but it would
have to be tiny to avoid blowing it up while running
red hot. Easier to just build the gear box, put the engine
on the dyno and measure the net HP out with and with out the
box connected to the turbo charger. Bottom line.

Paul Lamar ...No rotor no motor.

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