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RE: turbines. RE: [usa-tesla] Interesting Projects

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  • McGalliard, Frederick B
    Steam, at even a modest pressure and temperature, is going likely to be moving near sonic, to very supersonic. While I have some low temperature applications
    Message 1 of 18 , Apr 14, 2008
      Steam, at even a modest pressure and temperature, is going likely to be moving near sonic, to very supersonic. While I have some low temperature applications in mind, where the velocity of the "steam" (probably CO2 in my case) would be moving much slower, the thermodynamics of it requires the pressure difference and temperature provided to the nozzle to produce a very fast stream of gas to feed the turbine. This does limit on bearings, but there is a very interesting way to get around this. You might look up a recent article in the NASA Tech Briefs, describing a motor/generator designed to produce a magnetic bearing effect due to it's normal operation. The TT is a natural for a built in generator, and or an air bearing. A bit more cunning than I can do in my head, but the idea is simple enough at it's basic. 
       
      My analysis of the turbine begins without the turbine at all. Just the nozzle creating a very rapidly rotating vortex inside the housing. Done right the vortex will basically stall the nozzle with back pressure until the flow out the center is just equal to what we can force in.  Now place a disk into this stream. After thermal effects stabilize, the disk will be turning as fast as the gas, with some small effects I cannot easily analyze due to differences in speed as the gas drops in. I think the main factor here is drag from the housing. Since the unloaded disk has in principle zero net momentum transfer, it would drag the outer region slower, and drag the inner regions faster. Overall not much effect, I think. But loaded, now things start to change. As we tap out energy we slow the disk and the torque on it increases. This is reflected by decelerating force on the gas stream, and a greater flow out the center. If you were good at gas dynamics you could probably design the nozzle and housing, given the inlet/outlet conditions, so you could get a healthy vortex, rather than a slight flow diversion (I am trying to describe the two alternative limits, one over designed large, the other over designed small).
       
       


      From: Paul [mailto:teslat3@...]
      Sent: Tuesday, April 08, 2008 8:46 PM
      To: usa-tesla@yahoogroups.com
      Subject: RE: turbines. RE: [usa-tesla] Interesting Projects

      You are correct in your analysis. The smaller turbines constructed were prone to stall due to lack of surface area. An additional problem was that the turbine turned at a rate determined by the speed of the incoming steam. If the turbine was a small diameter, say one foot, the outside edge would only be a little over three foot in circumference. If the steam were moving only 100 MPH the turbine would rotate at 2933 RPM. That is the upper limit of most conventional bearings. If the speed of the steam were 400 MPH it would rotate at 11,000 rpm. Even if it only rotated at half that speed 5.500 RPM, due to slip, it would still exceed most of the bearings on the market now. A diameter of say 7.3 foot would bring the rotation down to around 2500 RPM which is within the range of most pillow block bearings.
      One advantage of the Tesla turbine is that the faster it turns the longer the steam takes to reach the center outlet. Larger rotors extract the same amount of energy at a slower speed due to the larger surface area. This also allows fewer rotors to be used as 28 inch diameter rotors have more than four times the surface area of a one foot diameter rotor.
      From my readings I have determined that the following factors are most important. Diameter, pressure difference, steam speed, disk spacing. Larger diameter would allow for less rotors to be used. Steam speed is important in that if supersonic steam speeds are used more kinetic energy is imparted to the rotors. Disk spacing is important to make the best use of the "working fluid" Steam is preferred over air due to the expansion and contraction properties of steam, which is related to pressure difference between inlet and outlet. Compressed air causes icing of the rotors and eventually blocks the air from passing through correctly.
      One factor that is limiting for the turbine is vibration. Working fluid passing between disks causes vibration in the rotors. I have added beville disk springs between the rotors to damp vibration. An additional factor is that the steam will be used periodically and not constantly.
      Paul

      .

    • Paul
      ... Helium bonded eramic coating would be ideal for blades (disks) as adhesion is increased. However pitting or grooving will disrupt adhesion to the surface
      Message 2 of 18 , Apr 17, 2008
        -----Original Message-----
        >From: "McGalliard, Frederick B" <frederick.b.mcgalliard@...>
        >Sent: Apr 10, 2008 10:31 AM
        >To: usa-tesla@yahoogroups.com
        >Subject: RE: turbines. RE: [usa-tesla] Interesting Projects
        >

        >
        >One area I have no real grasp of. The spiral path of the exhaust gas is
        >clear enough. What is not clear is whether there are ways to increase
        >the aerodynamic interaction to get a higher efficiency, or at least make
        >the power to weight ratio better. I think a rippled path, sort of like a
        >vinyl record that has been melted and sagged along a number of radii.
        >This would change the direction of the gas flow, and interact with it in
        >a strongly aerodynamic way. It should really increase the coupling. And
        >if we built this from layers of ceramic, as example, we could shape the
        >interplate structures to have interesting aerodynamic characteristics,
        >somewhat like a turbines blade in it's effect, but with a spiral flow so
        >the dozens of blades in series are all on a single disk. It may not be a
        >pure TT, but it may be a very useful system.
        >
        >_


        Helium bonded eramic coating would be ideal for blades (disks) as adhesion is increased. However pitting or grooving will disrupt adhesion to the surface and prevent smooth flow over the surface.


        >From: davep@... [mailto:davep@...]
        >Sent: Thursday, April 10, 2008 12:47 AM
        >To: usa-tesla@yahoogroups.com
        >Subject: Re: turbines. RE: [usa-tesla] Interesting Projects
        >
        >
        >
        >Its simple:
        >The Tesla design has been in the open literature, off patent,
        >for 90 odd years.
        >
        >The bladed turbines routinely achieve (multi rotor) the highest
        >efficiencies (at peak efficiency....) known, 80 odd%, of
        >any 'heat engine'. They are manufactured and developed by
        >multiple companies, with multimegabuck development budgets,
        >who would cheerfully adopt any workable improvement. One may
        >draw certain inferences from the fact that they have not adopted
        >disk rotors.
        >(Note: the '80 odd %' is for the turbine rotors alone, the
        >combustion Gas Turbine set, (jet engine) achieves 40 odd% because
        >there are two sets of rotors: compressor and power....)
        >
        >'friction losses' on the blading is low, just as in a/c wings, etc.
        >This is reflected in the high efficiencies _measured_. The high
        >efficiencies also follow from the multi rotor design: each rotor
        >handles 'gas' at slightly different speed/temperature/pressure,
        >with blades optimized for that portion.
        >
        >Running 'on a vacuum' (alone) would be hideously inefficient, as,
        >at best 14 psi is available. (Power plant steam runs 500psi and up.
        >and is _hot_: that heat energy is also recovered by the turbine
        >rotors.)
        >
        >This sort of stuff is PhD level work to get really good at...
        >(I know, near as i can tell, a bit. Great thick books cover
        >130 years of turbine, 230 odd of steam engine design.
        >
        >best
        >dwp
        >
        >
        >
        >
      • Paul
        ... (Comment) The disks of a Tesla turbine are identical to a disk generator. A magnetic field that completely covered both (flat) sides of the disks would
        Message 3 of 18 , Apr 17, 2008
          -----Original Message-----
          >From: "McGalliard, Frederick B" <frederick.b.mcgalliard@...>
          >Sent: Apr 14, 2008 5:57 PM
          >To: usa-tesla@yahoogroups.com
          >Subject: RE: turbines. RE: [usa-tesla] Interesting Projects
          >
          >Steam, at even a modest pressure and temperature, is going likely to be
          >moving near sonic, to very supersonic. While I have some low temperature
          >applications in mind, where the velocity of the "steam" (probably CO2 in
          >my case) would be moving much slower, the thermodynamics of it requires
          >the pressure difference and temperature provided to the nozzle to
          >produce a very fast stream of gas to feed the turbine. This does limit
          >on bearings, but there is a very interesting way to get around this. You
          >might look up a recent article in the NASA Tech Briefs, describing a
          >motor/generator designed to produce a magnetic bearing effect due to
          >it's normal operation. The TT is a natural for a built in generator, and
          >or an air bearing. A bit more cunning than I can do in my head, but the
          >idea is simple enough at it's basic.
          >
          (Comment)
          The disks of a Tesla turbine are identical to a disk generator. A magnetic field that completely covered both (flat) sides of the disks would cause a charge to be present in the disks. It is possible to oppositely charge two disks on the same shaft so that a capacitor is formed. Tesla also noted that by applying a magnetic field that a copper disk could be brought into rapid rotation.

          c3=5170406>
          >
        • McGalliard, Frederick B
          Lacking the good sense to keep quiet on things I really know only a little about, I comment. The TT disks also look exactly like the disks of a Wimsherst
          Message 4 of 18 , Apr 18, 2008
            Lacking the good sense to keep quiet on things I really know only a little about, I comment.
            The TT disks also look exactly like the disks of a Wimsherst generator. A series of conductive plates, or perhaps, in a metal disk, a series of segments of imbedded ceramic, could form one plate of a variable capacitor, or more than one, that can be used to pump a DC charge, as the Wimsherst generator does, or to produce an AC power supply. If I have the idea right, a KV or so on the plates, and a larger external capacitor with a transformer between the two, and the variations in the capacitance as the disk rotates will pump the current back and forth, providing power without commutation rings or any contact at all with the rotating member. Should work pretty nicely. no idea if it will produce anywhere near the energy per pound, but for a very rapidly rotating disk, it may be much easier to seal than a shaft to an alternator. And it may be much lighter. I kind of like the simple elegance of it.


            From: Paul [mailto:teslat3@...]
            Sent: Thursday, April 17, 2008 10:18 PM
            To: usa-tesla@yahoogroups.com
            Subject: RE: turbines. RE: [usa-tesla] Interesting Projects



            -----Original Message-----

            >From: "McGalliard, Frederick B"
            <frederick.b. mcgalliard@ BOEING.COM>
            >Sent:
            Apr 14, 2008 5:57 PM
            >To:
            href="mailto:usa-tesla%40yahoogroups.com">usa-tesla@yahoogrou ps.com
            >Subject:
            RE: turbines. RE: [usa-tesla] Interesting Projects
            >
            >Steam, at even
            a modest pressure and temperature, is going likely to be
            >moving near
            sonic, to very supersonic. While I have some low temperature
            >applications
            in mind, where the velocity of the "steam" (probably CO2 in
            >my case)
            would be moving much slower, the thermodynamics of it requires
            >the
            pressure difference and temperature provided to the nozzle to
            >produce a
            very fast stream of gas to feed the turbine. This does limit
            >on bearings,
            but there is a very interesting way to get around this. You
            >might look up
            a recent article in the NASA Tech Briefs, describing a
            >motor/generator
            designed to produce a magnetic bearing effect due to
            >it's normal
            operation. The TT is a natural for a built in generator, and
            >or an air
            bearing. A bit more cunning than I can do in my head, but the
            >idea is
            simple enough at it's basic.
            >
            (Comment)
            The disks of a Tesla turbine are identical to a disk generator. A magnetic field that completely covered both (flat) sides of the disks would cause a charge to be present in the disks. It is possible to oppositely charge two disks on the same shaft so that a capacitor is formed. Tesla also noted that by applying a magnetic field that a copper disk could be brought into rapid rotation.

            c3=5170406>
            >

          • McGalliard, Frederick B
            The pitting is the secret of the Golf ball, isn t it? Disrupt the laminar flow and reduce the drag effects. Of course if we coupled to the flow by aerodynamic
            Message 5 of 18 , Apr 18, 2008
              The pitting is the secret of the Golf ball, isn't it?
              Disrupt the laminar flow and reduce the drag effects.
              Of course if we coupled to the flow by aerodynamic effects, we might find reducing the drag to be salubrious. I think that one is one for the experimental physicist though. We need some idea of how a perfectly designed TT works to compare to a modified one.


              From: Paul [mailto:teslat3@...]
              Sent: Thursday, April 17, 2008 10:03 PM
              To: usa-tesla@yahoogroups.com
              Subject: RE: turbines. RE: [usa-tesla] Interesting Projects



              -----Original Message-----

              >From: "McGalliard, Frederick B"
              <frederick.b. mcgalliard@ BOEING.COM>
              >Sent:
              Apr 10, 2008 10:31 AM
              >To:
              href="mailto:usa-tesla%40yahoogroups.com">usa-tesla@yahoogrou ps.com
              >Subject:
              RE: turbines. RE: [usa-tesla] Interesting Projects
              >

              >
              >One area I have no real grasp of. The spiral path of the exhaust gas
              is
              >clear enough. What is not clear is whether there are ways to
              increase
              >the aerodynamic interaction to get a higher efficiency, or at
              least make
              >the power to weight ratio better. I think a rippled path, sort
              of like a
              >vinyl record that has been melted and sagged along a number of
              radii.
              >This would change the direction of the gas flow, and interact with
              it in
              >a strongly aerodynamic way. It should really increase the coupling.
              And
              >if we built this from layers of ceramic, as example, we could shape
              the
              >interplate structures to have interesting aerodynamic
              characteristics,
              >somewhat like a turbines blade in it's effect, but with
              a spiral flow so
              >the dozens of blades in series are all on a single disk.
              It may not be a
              >pure TT, but it may be a very useful
              system.
              >
              >_

              Helium bonded eramic coating would be ideal for blades (disks) as adhesion is increased. However pitting or grooving will disrupt adhesion to the surface and prevent smooth flow over the surface.

              >From: davep@...
              [mailto:davep@...]
              >Sent:
              Thursday, April 10, 2008 12:47 AM
              >To:
              href="mailto:usa-tesla%40yahoogroups.com">usa-tesla@yahoogrou ps.com
              >Subject:
              Re: turbines. RE: [usa-tesla] Interesting Projects
              >
              >
              >
              >Its simple:
              >The Tesla design has
              been in the open literature, off patent,
              >for 90 odd
              years.
              >
              >The bladed turbines routinely achieve (multi rotor) the
              highest
              >efficiencies (at peak efficiency.. ..) known, 80 odd%,
              of
              >any 'heat engine'. They are manufactured and developed
              by
              >multiple companies, with multimegabuck development budgets,
              >who
              would cheerfully adopt any workable improvement. One may
              >draw certain
              inferences from the fact that they have not adopted
              >disk
              rotors.
              >(Note: the '80 odd %' is for the turbine rotors alone,
              the
              >combustion Gas Turbine set, (jet engine) achieves 40 odd%
              because
              >there are two sets of rotors: compressor and
              power....)
              >
              >'friction losses' on the blading is low, just as in
              a/c wings, etc.
              >This is reflected in the high efficiencies _measured_.
              The high
              >efficiencies also follow from the multi rotor design: each
              rotor
              >handles 'gas' at slightly different
              speed/temperature/ pressure,
              >with blades optimized for that
              portion.
              >
              >Running 'on a vacuum' (alone) would be hideously
              inefficient, as,
              >at best 14 psi is available. (Power plant steam runs
              500psi and up.
              >and is _hot_: that heat energy is also recovered by the
              turbine
              >rotors.)
              >
              >This sort of stuff is PhD level work to
              get really good at...
              >(I know, near as i can tell, a bit. Great thick
              books cover
              >130 years of turbine, 230 odd of steam engine
              design.
              >
              >best
              >dwp
              >
              >
              >
              >

            • Paul
              If you replaced the rotors of a turbine with large plastic or other non conductive disks, you could create a hugh static charge by pumping air between the
              Message 6 of 18 , Apr 21, 2008
                If you replaced the rotors of a turbine with large plastic or other non conductive disks, you could create a hugh static charge by pumping air between the rotors. Pump the air though a dry non conductive circular tube about 120 foot long, and you can really create a large static charge.


                -----Original Message-----
                >From: "McGalliard, Frederick B" <frederick.b.mcgalliard@...>
                >Sent: Apr 18, 2008 9:44 AM
                >To: usa-tesla@yahoogroups.com
                >Subject: RE: turbines. RE: [usa-tesla] Interesting Projects
                >
                >Lacking the good sense to keep quiet on things I really know only a
                >little about, I comment.
                >The TT disks also look exactly like the disks of a Wimsherst generator.
                >A series of conductive plates, or perhaps, in a metal disk, a series of
                >segments of imbedded ceramic, could form one plate of a variable
                >capacitor, or more than one, that can be used to pump a DC charge, as
                >the Wimsherst generator does, or to produce an AC power supply. If I
                >have the idea right, a KV or so on the plates, and a larger external
                >capacitor with a transformer between the two, and the variations in the
                >capacitance as the disk rotates will pump the current back and forth,
                >providing power without commutation rings or any contact at all with the
                >rotating member. Should work pretty nicely. no idea if it will produce
                >anywhere near the energy per pound, but for a very rapidly rotating
                >disk, it may be much easier to seal than a shaft to an alternator. And
                >it may be much lighter. I kind of like the simple elegance of it.
                >
                >________________________________
                >
                >From: Paul [mailto:teslat3@...]
                >Sent: Thursday, April 17, 2008 10:18 PM
                >To: usa-tesla@yahoogroups.com
                >Subject: RE: turbines. RE: [usa-tesla] Interesting Projects
                >
                >
                >
                >
                >
                >-----Original Message-----
                >>From: "McGalliard, Frederick B" <frederick.b.mcgalliard@...
                ><mailto:frederick.b.mcgalliard%40BOEING.COM> >
                >>Sent: Apr 14, 2008 5:57 PM
                >>To: usa-tesla@yahoogroups.com <mailto:usa-tesla%40yahoogroups.com>
                >>Subject: RE: turbines. RE: [usa-tesla] Interesting Projects
                >>
                >>Steam, at even a modest pressure and temperature, is going likely to be
                >>moving near sonic, to very supersonic. While I have some low
                >temperature
                >>applications in mind, where the velocity of the "steam" (probably CO2
                >in
                >>my case) would be moving much slower, the thermodynamics of it requires
                >>the pressure difference and temperature provided to the nozzle to
                >>produce a very fast stream of gas to feed the turbine. This does limit
                >>on bearings, but there is a very interesting way to get around this.
                >You
                >>might look up a recent article in the NASA Tech Briefs, describing a
                >>motor/generator designed to produce a magnetic bearing effect due to
                >>it's normal operation. The TT is a natural for a built in generator,
                >and
                >>or an air bearing. A bit more cunning than I can do in my head, but the
                >>idea is simple enough at it's basic.
                >>
                >(Comment)
                >The disks of a Tesla turbine are identical to a disk generator. A
                >magnetic field that completely covered both (flat) sides of the disks
                >would cause a charge to be present in the disks. It is possible to
                >oppositely charge two disks on the same shaft so that a capacitor is
                >formed. Tesla also noted that by applying a magnetic field that a copper
                >disk could be brought into rapid rotation.
                >
                >c3=5170406>
                >>
                >
                >
                >
                >
              • Paul
                It is my understanding that helium bonded ceramic surfaces are very sticky and this is because the surface is flawless, there is no disruption of flow. This
                Message 7 of 18 , Apr 21, 2008
                  It is my understanding that helium bonded ceramic surfaces are very "sticky" and this is because the surface is flawless, there is no disruption of flow. This surface would be perfect for the disk and would also make the disk non conductive on the surface.

                  -----Original Message-----
                  >From: "McGalliard, Frederick B" <frederick.b.mcgalliard@...>
                  >Sent: Apr 18, 2008 9:48 AM
                  >To: usa-tesla@yahoogroups.com
                  >Subject: RE: turbines. RE: [usa-tesla] Interesting Projects
                  >
                  >The pitting is the secret of the Golf ball, isn't it?
                  >Disrupt the laminar flow and reduce the drag effects.
                  >Of course if we coupled to the flow by aerodynamic effects, we might
                  >find reducing the drag to be salubrious. I think that one is one for the
                  >experimental physicist though. We need some idea of how a perfectly
                  >designed TT works to compare to a modified one.
                  >
                  >________________________________
                  >
                  >From: Paul [mailto:teslat3@...]
                  >Sent: Thursday, April 17, 2008 10:03 PM
                  >To: usa-tesla@yahoogroups.com
                  >Subject: RE: turbines. RE: [usa-tesla] Interesting Projects
                  >
                  >
                  >
                  >
                  >
                  >-----Original Message-----
                  >>From: "McGalliard, Frederick B" <frederick.b.mcgalliard@...
                  ><mailto:frederick.b.mcgalliard%40BOEING.COM> >
                  >>Sent: Apr 10, 2008 10:31 AM
                  >>To: usa-tesla@yahoogroups.com <mailto:usa-tesla%40yahoogroups.com>
                  >>Subject: RE: turbines. RE: [usa-tesla] Interesting Projects
                  >>
                  >
                  >>
                  >>One area I have no real grasp of. The spiral path of the exhaust gas is
                  >>clear enough. What is not clear is whether there are ways to increase
                  >>the aerodynamic interaction to get a higher efficiency, or at least
                  >make
                  >>the power to weight ratio better. I think a rippled path, sort of like
                  >a
                  >>vinyl record that has been melted and sagged along a number of radii.
                  >>This would change the direction of the gas flow, and interact with it
                  >in
                  >>a strongly aerodynamic way. It should really increase the coupling. And
                  >>if we built this from layers of ceramic, as example, we could shape the
                  >>interplate structures to have interesting aerodynamic characteristics,
                  >>somewhat like a turbines blade in it's effect, but with a spiral flow
                  >so
                  >>the dozens of blades in series are all on a single disk. It may not be
                  >a
                  >>pure TT, but it may be a very useful system.
                  >>
                  >>_
                  >
                  >Helium bonded eramic coating would be ideal for blades (disks) as
                  >adhesion is increased. However pitting or grooving will disrupt adhesion
                  >to the surface and prevent smooth flow over the surface.
                  >
                  >>From: davep@... <mailto:davep%40quik.com> [mailto:davep@...
                  ><mailto:davep%40quik.com> ]
                  >>Sent: Thursday, April 10, 2008 12:47 AM
                  >>To: usa-tesla@yahoogroups.com <mailto:usa-tesla%40yahoogroups.com>
                  >>Subject: Re: turbines. RE: [usa-tesla] Interesting Projects
                  >>
                  >>
                  >>
                  >>Its simple:
                  >>The Tesla design has been in the open literature, off patent,
                  >>for 90 odd years.
                  >>
                  >>The bladed turbines routinely achieve (multi rotor) the highest
                  >>efficiencies (at peak efficiency....) known, 80 odd%, of
                  >>any 'heat engine'. They are manufactured and developed by
                  >>multiple companies, with multimegabuck development budgets,
                  >>who would cheerfully adopt any workable improvement. One may
                  >>draw certain inferences from the fact that they have not adopted
                  >>disk rotors.
                  >>(Note: the '80 odd %' is for the turbine rotors alone, the
                  >>combustion Gas Turbine set, (jet engine) achieves 40 odd% because
                  >>there are two sets of rotors: compressor and power....)
                  >>
                  >>'friction losses' on the blading is low, just as in a/c wings, etc.
                  >>This is reflected in the high efficiencies _measured_. The high
                  >>efficiencies also follow from the multi rotor design: each rotor
                  >>handles 'gas' at slightly different speed/temperature/pressure,
                  >>with blades optimized for that portion.
                  >>
                  >>Running 'on a vacuum' (alone) would be hideously inefficient, as,
                  >>at best 14 psi is available. (Power plant steam runs 500psi and up.
                  >>and is _hot_: that heat energy is also recovered by the turbine
                  >>rotors.)
                  >>
                  >>This sort of stuff is PhD level work to get really good at...
                  >>(I know, near as i can tell, a bit. Great thick books cover
                  >>130 years of turbine, 230 odd of steam engine design.
                  >>
                  >>best
                  >>dwp
                  >>
                  >>
                  >>
                  >>
                  >
                  >
                  >
                  >
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