## Re: [TeslaTurbine] Re: Information wanted

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• ... Not zero. As the fluid spirals in towards the center of the disc it loses velocity and imparts its momentum to the disc, thus generating torque. A disc
Message 1 of 8 , Mar 27, 2002
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> I suspect that it is maximum **power** at 1/2 speed. at zero speed,
> the torque would be max, at speed equal to steam speed the torque
> would be zero.

Not zero. As the fluid spirals in towards the center of the disc it loses
velocity and imparts its momentum to the disc, thus generating torque. A
disc with zero torque would also have zero power -- which is hardly
efficient. :-) Maximum efficiency is attained when the speeds are equal
because there is minimal turbulence and frictional drag. As fluid velocity
increases there is more momentum to transfer, but more energy is lost to
friction and turbulence. At some point the fluid flow will cease being
laminar, but why that occurs at precisely twice the disc speed is something
that I do not understand. The standard factor of two may just be a
convenient round number.

-DeLesley Hutchins
• ... Welcome to the world of little-known engine designs. :-) Your best bet would be to find an old junker (non-train) boiler, build a Tesla turbine, and
Message 2 of 8 , Mar 27, 2002
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> However, herein lies the problem; try as I might I have so far been
> unable to unearth any torque or steam consumption curves which will
> allow me to determine the boiler design which will be based on the

Welcome to the world of little-known engine designs. :-) Your best bet
would be to find an old junker (non-train) boiler, build a Tesla turbine,
and measure the curves yourself. Then you can build a real boiler, a second
turbine to overcome the problems you found with the first, and put it in the
train. A third iteration will probably be required to get everything right.
If you want proven plans then go with a piston engine.

-DeLesley Hutchins
• Hi Mike. Sonic steam. Reminds me of the short movie of stage separation on the Saturn 5. The second stage pulls away from the interstage, the H2 O2 rockets
Message 3 of 8 , Mar 28, 2002
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Hi Mike. Sonic steam. Reminds me of the short movie of stage separation on
the Saturn 5. The second stage pulls away from the interstage, the H2 O2
rockets blasting like crazy but totally invisible steam is all that comes
out, till the interstage slips into the stream and fire flashes all along
it. Sure, steam can go supersonic. You just need enough pressure and a high
enough temperature. At a rough guess you will need around 400 PSI. The
nozzle converts the heat/pressure into velocity so the exit steam is much
cooler and will condense unless it is superheated. For a TT you may not care
if it condenses a little, since the droplets will not impact the blades as
they do in a standard turbine, but you don't want to have too much
condensation. It would get in the way of the gas flow.

The 1/2 V maximum is, I think, the point where the turbine produces the most
power. The most efficiency is much closer to V.

-----Original Message-----
From: Mike Passerotti [mailto:mpasserotti@...]
...
Is there a possibility of sonic speeds with steam? I don't remember seeing
that anywhere.
...
Maximum torque transfer from the fluid to disk is reported to be when the
fluid is traveling 2 times the speed of the disk.
• for sonic flow Ptot/P = (1+ M^2 *(gama -1)/2)^(gamma/(gamma-1)) gamma is the ratio of Cp/Cv M is the mach number Ptot is total pressure P is free stream
Message 4 of 8 , Mar 28, 2002
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for sonic flow

Ptot/P = (1+ M^2 *(gama -1)/2)^(gamma/(gamma-1))

gamma is the ratio of Cp/Cv
M is the mach number
Ptot is total pressure
P is free stream pressure

you can find the Cp and Cv by looking up the properties in steam
tables Cp = dh/dT and Cv = d(h-Pv)/dt. There is an excel spreadsheet
add in that will give the values you need. Its called either
"water.xla" or "wasser.xla"

Chris

--- In TeslaTurbine@y..., "McGalliard, Frederick B"
<frederick.b.mcgalliard@B...> wrote:
> Hi Mike. Sonic steam. Reminds me of the short movie of stage
separation on
> the Saturn 5. The second stage pulls away from the interstage, the
H2 O2
> rockets blasting like crazy but totally invisible steam is all that
comes
> out, till the interstage slips into the stream and fire flashes all
along
> it. Sure, steam can go supersonic. You just need enough pressure and
a high
> enough temperature. At a rough guess you will need around 400 PSI.
The
> nozzle converts the heat/pressure into velocity so the exit steam is
much
> cooler and will condense unless it is superheated. For a TT you may
not care
> if it condenses a little, since the droplets will not impact the
> they do in a standard turbine, but you don't want to have too much
> condensation. It would get in the way of the gas flow.
>
> The 1/2 V maximum is, I think, the point where the turbine produces
the most
> power. The most efficiency is much closer to V.
>
> -----Original Message-----
> From: Mike Passerotti [mailto:mpasserotti@m...]
> ...
> Is there a possibility of sonic speeds with steam? I don't remember
seeing
> that anywhere.
> ...
> Maximum torque transfer from the fluid to disk is reported to be
when the
> fluid is traveling 2 times the speed of the disk.
• Thanks everyone. Have a happy Easter. Mike Passerotti
Message 5 of 8 , Mar 29, 2002
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Thanks everyone. Have a happy Easter.

Mike Passerotti
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