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Re: [TeslaTurbine] Re: Information wanted

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  • DeLesley Hutchins
    ... 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
    • 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
      • McGalliard, Frederick B
        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.
        • the_maniacal_engineer
          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
            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@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.
          • Mike Passerotti
            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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