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Re: Peter R Payne and proper boats.

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  • Richard Mundy
    Hi David, I intend to start with a copper pipe and braze a end cap on. Get this working then start experimenting. I like the idea of an air receiver/spring, by
    Message 1 of 29 , Jan 19, 2009
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      Hi David,
      I intend to start with a copper pipe and braze a end cap on. Get this
      working then start experimenting. I like the idea of an air
      receiver/spring, by all accounts I am waisting my time tho.

      I did try emailing Graeme Payne, but it bounced, but then I don't
      think Compuserve have existed for some years.

      Will post failures as well as successes(if any!).

      Dick

      --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
      <dh1@...> wrote:
      >
      > Go for it.
      >
      > How about using an air receiver/accumulator out of a hydraulic
      system as
      > the "spring" ?
      >
      > Should
      >
      > David 1/2d
      >
      > --------------------------------------------------
      > From: "Richard Mundy" <coracles18@...>
      > Sent: Sunday, January 18, 2009 6:14 PM
      > To: <pop-pop-steamboats@yahoogroups.com>
      > Subject: [pop-pop-steamboats] Re: Peter R Payne and proper boats.
      >
      > > Hi Jean-Yves,
      > >
      > > There is a superb simplicity and brutality about these big
      engines,
      > > I still can't resist the temptation to play!
      > >
      >
    • Pete B.
      Hi Dick, For starters check out Dan Noyes s photo album Dory pop-pop , images 21-28. He has a 4 pop-pop boat and a couple of engine larger engine designs.
      Message 2 of 29 , Jan 19, 2009
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        Hi Dick,

        For starters check out Dan Noyes's photo album "Dory pop-pop", images 21-28. He has a 4' pop-pop boat and a couple of  engine larger engine designs.

         

        Boiler building directions: dory engine and experimental "Hammer Head" engine
         
        Dan would more than gladly share his experiences.
         
        Pete

        --- In pop-pop-steamboats@yahoogroups.com, "Richard Mundy" <coracles18@...> wrote:
        >
        > Hi David,
        > I intend to start with a copper pipe and braze a end cap on. Get this
        > working then start experimenting. I like the idea of an air
        > receiver/spring, by all accounts I am waisting my time tho.
        >
        > I did try emailing Graeme Payne, but it bounced, but then I don't
        > think Compuserve have existed for some years.
        >
        > Will post failures as well as successes(if any!).
        >
        > Dick
        >
        > --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
        > dh1@ wrote:
        > >
        > > Go for it.
        > >
        > > How about using an air receiver/accumulator out of a hydraulic
        > system as
        > > the "spring" ?
        > >
        > > Should
        > >
        > > David 1/2d
        > >
        > > --------------------------------------------------
        > > From: "Richard Mundy" coracles18@
        > > Sent: Sunday, January 18, 2009 6:14 PM
        > > To: pop-pop-steamboats@yahoogroups.com
        > > Subject: [pop-pop-steamboats] Re: Peter R Payne and proper boats.
        > >
        > > > Hi Jean-Yves,
        > > >
        > > > There is a superb simplicity and brutality about these big
        > engines,
        > > > I still can't resist the temptation to play!
        > > >
        > >
        >
      • Richard Mundy
        Hi Pete, thanks for this. Finally got round to looking at Paynes second pop pop patent(4,057,961). This is not a pop pop, but is a diesel, steam or compresed
        Message 3 of 29 , Jan 20, 2009
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          Hi Pete,
          thanks for this. Finally got round to looking at Paynes second pop
          pop patent(4,057,961). This is not a pop pop, but is a diesel, steam
          or compresed air pump suitable for propulsion. The existance of this
          patent indicates to me thst he felt his previous patent device was
          not efficient. It worked, but not that well (as everyone has been
          telling me).
          My own thoughts on this are the problem is the spead of creating
          steam. With a small model you only need to heat a drop of water.
          As the engines grow bigger there is a need to create a lot of steam a
          lot faster. The hammer head boiler goes some way to achieving this.
          I suspect better would be a multitube flash steam boiler. Or to heat
          the water by microwave!
          The water needs to get down that tube fast!

          Dick



          --- In pop-pop-steamboats@yahoogroups.com, "Pete B." <georgeyyy@...>
          wrote:
          >
          >
          > Hi Dick,
          >
          > For starters check out Dan Noyes's photo album "Dory pop-pop",
          images
          > 21-28. He has a 4' pop-pop boat and a couple of engine larger
          engine
          > designs.
          >
          >
          > Boiler building directions: dory engine and experimental "Hammer
          Head"
          > engine Dan would more than gladly share his experiences. Pete
          > --- In pop-pop-steamboats@yahoogroups.com, "Richard Mundy"
          > <coracles18@> wrote:
          > >
          > > Hi David,
          > > I intend to start with a copper pipe and braze a end cap on. Get
          this
          > > working then start experimenting. I like the idea of an air
          > > receiver/spring, by all accounts I am waisting my time tho.
          > >
          > > I did try emailing Graeme Payne, but it bounced, but then I don't
          > > think Compuserve have existed for some years.
          > >
          > > Will post failures as well as successes(if any!).
          > >
          > > Dick
          > >
          > > --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
          > > dh1@ wrote:
          > > >
          > > > Go for it.
          > > >
          > > > How about using an air receiver/accumulator out of a hydraulic
          > > system as
          > > > the "spring" ?
          > > >
          > > > Should
          > > >
          > > > David 1/2d
          > > >
          > > > --------------------------------------------------
          > > > From: "Richard Mundy" coracles18@
          > > > Sent: Sunday, January 18, 2009 6:14 PM
          > > > To: pop-pop-steamboats@yahoogroups.com
          > > > Subject: [pop-pop-steamboats] Re: Peter R Payne and proper
          boats.
          > > >
          > > > > Hi Jean-Yves,
          > > > >
          > > > > There is a superb simplicity and brutality about these big
          > > engines,
          > > > > I still can't resist the temptation to play!
          > > > >
          > > >
          > >
          >
        • David Halfpenny
          ... From: Richard Mundy Sent: Tuesday, January 20, 2009 7:44 PM ... AND then condense a tube-full of it in a similar time, in the
          Message 4 of 29 , Jan 20, 2009
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            --------------------------------------------------
            From: "Richard Mundy" <coracles18@...>
            Sent: Tuesday, January 20, 2009 7:44 PM

            > As the engines grow bigger there is a need to create a lot of steam a
            > lot faster.

            AND then condense a tube-full of it in a similar time, in the very boiler
            you have just heated it in!

            That is exactly the snag that Newcomen had - though with much less thermal
            capacity to heat and cool each pulse.

            David 1/2d
          • Richard Mundy
            Hi David, I think the condensing is done in the tube, which creates another problem. Condensing steam in a tiny tube is a lot quicker than doing it in a big
            Message 5 of 29 , Jan 20, 2009
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              Hi David,
              I think the condensing is done in the tube, which creates another
              problem. Condensing steam in a tiny tube is a lot quicker than doing
              it in a big tube.
              An interesting aspect of Paynes original patent is using the momentum
              of the returning water to compress the remaining steam in the boiler.
              This should raise the boiling point so the steam has more kick to it.
              If this effect is significant I have no idea.
              More important I suspect is to have a forward facing intake and
              valves.
              Also, what about an output nozzle? you can significantly increase the
              velocity of water coming out of a hosepipe by sticking your finger
              over the end.
              This would also increase the pressure in the boiler and give the
              whole thing more go?

              Dick



              --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
              <dh1@...> wrote:
              >
              >
              >
              > --------------------------------------------------
              > From: "Richard Mundy" <coracles18@...>
              > Sent: Tuesday, January 20, 2009 7:44 PM
              >
              > > As the engines grow bigger there is a need to create a lot of
              steam a
              > > lot faster.
              >
              > AND then condense a tube-full of it in a similar time, in the very
              boiler
              > you have just heated it in!
              >
              > That is exactly the snag that Newcomen had - though with much less
              thermal
              > capacity to heat and cool each pulse.
              >
              > David 1/2d
              >
            • Sparks, Matthew - McClatchy Corporate
              If you really want to see what you re up against, check out the mythbusters episode where they took a fiberglass speedboat hull and mounted two of the large
              Message 6 of 29 , Jan 20, 2009
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                If you really want to see what you're up against, check out the
                mythbusters episode where they took a fiberglass speedboat hull and
                mounted two of the large compressed air cylineders.

                http://televizzle.org/2006/12/06/air-cylinder-rocket/

                Matt Sparks -

                -----Original Message-----
                From: pop-pop-steamboats@yahoogroups.com
                [mailto:pop-pop-steamboats@yahoogroups.com] On Behalf Of Richard Mundy
                Sent: Tuesday, January 20, 2009 2:03 PM
                To: pop-pop-steamboats@yahoogroups.com
                Subject: [pop-pop-steamboats] Re: Peter R Payne and proper boats.

                Hi David,
                I think the condensing is done in the tube, which creates another
                problem. Condensing steam in a tiny tube is a lot quicker than doing
                it in a big tube.
                An interesting aspect of Paynes original patent is using the momentum
                of the returning water to compress the remaining steam in the boiler.
                This should raise the boiling point so the steam has more kick to it.
                If this effect is significant I have no idea.
                More important I suspect is to have a forward facing intake and
                valves.
                Also, what about an output nozzle? you can significantly increase the
                velocity of water coming out of a hosepipe by sticking your finger
                over the end.
                This would also increase the pressure in the boiler and give the
                whole thing more go?

                Dick



                --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
                <dh1@...> wrote:
                >
                >
                >
                > --------------------------------------------------
                > From: "Richard Mundy" <coracles18@...>
                > Sent: Tuesday, January 20, 2009 7:44 PM
                >
                > > As the engines grow bigger there is a need to create a lot of
                steam a
                > > lot faster.
                >
                > AND then condense a tube-full of it in a similar time, in the very
                boiler
                > you have just heated it in!
                >
                > That is exactly the snag that Newcomen had - though with much less
                thermal
                > capacity to heat and cool each pulse.
                >
                > David 1/2d
                >



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

                Yahoo! Groups Links
              • Jean-Yves Renaud
                Hi Dick, I would like to comment 2 topics of your last post: facing intake and nozzle. 1°) Facing intake. Everybody thinks at the beginning that using a
                Message 7 of 29 , Jan 21, 2009
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                  Hi Dick,
                  I would like to comment 2 topics of your last post: facing intake and
                  nozzle.
                  1°) Facing intake.
                  Everybody thinks at the beginning that using a facing intake (and
                  valves) could improve the performance of pop-pop propulsion. Even
                  Peter Payne thought that. But facing intake is useless, or more
                  exactly so inefficient that it becomes useless.
                  • By math demo it can be proven that the effect of such a
                  modification is negligible.
                  • For those who dislike math, there is an easy way to check
                  that sucking is far less efficient than blowing. Try to blow a candle
                  by sucking air!
                  • In addition, to prove this inefficiency, 2 years ago I built
                  a small boat with an electric pump to show that sucking water on the
                  bow has a negligible impact; though a jet backward propels. The
                  pulling force (when sucking) was roughly 20 millions times weaker
                  than the pushing one.
                  2°) Nozzle.
                  The thrust of a waterjet evolving with the square of the velocity of
                  the water that is expelled it seems evident that a nozzle could
                  improve the performance. However, on a pop-pop engine a nozzle acts
                  also on the frequency, stroke volume…and this is detrimental. We
                  don't know enough to give precise figures, but it seems that the best
                  nozzle has a diameter reduced by only 5 to 10%. On this forum Daryl
                  is very likely the one who has got the best practical knowledge on
                  this topic. Most of his engines are provided with nozzles and his
                  engines are among the best ones if not the best.
                  Jean-Yves


                  --- In pop-pop-steamboats@yahoogroups.com, "Richard Mundy"
                  <coracles18@...> wrote:
                  >
                  > Hi David,
                  > I think the condensing is done in the tube, which creates another
                  > problem. Condensing steam in a tiny tube is a lot quicker than
                  doing
                  > it in a big tube.
                  > An interesting aspect of Paynes original patent is using the
                  momentum
                  > of the returning water to compress the remaining steam in the
                  boiler.
                  > This should raise the boiling point so the steam has more kick to
                  it.
                  > If this effect is significant I have no idea.
                  > More important I suspect is to have a forward facing intake and
                  > valves.
                  > Also, what about an output nozzle? you can significantly increase
                  the
                  > velocity of water coming out of a hosepipe by sticking your finger
                  > over the end.
                  > This would also increase the pressure in the boiler and give the
                  > whole thing more go?
                  >
                  > Dick
                  >
                  >
                  >
                  > --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
                  > <dh1@> wrote:
                  > >
                  > >
                  > >
                  > > --------------------------------------------------
                  > > From: "Richard Mundy" <coracles18@>
                  > > Sent: Tuesday, January 20, 2009 7:44 PM
                  > >
                  > > > As the engines grow bigger there is a need to create a lot of
                  > steam a
                  > > > lot faster.
                  > >
                  > > AND then condense a tube-full of it in a similar time, in the
                  very
                  > boiler
                  > > you have just heated it in!
                  > >
                  > > That is exactly the snag that Newcomen had - though with much
                  less
                  > thermal
                  > > capacity to heat and cool each pulse.
                  > >
                  > > David 1/2d
                  > >
                  >
                • David Halfpenny
                  ... From: Richard Mundy Sent: Tuesday, January 20, 2009 10:02 PM To: Subject:
                  Message 8 of 29 , Jan 21, 2009
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                    --------------------------------------------------
                    From: "Richard Mundy" <coracles18@...>
                    Sent: Tuesday, January 20, 2009 10:02 PM
                    To: <pop-pop-steamboats@yahoogroups.com>
                    Subject: [pop-pop-steamboats] Re: Peter R Payne and proper boats.

                    > Hi David,
                    > I think the condensing is done in the tube, which creates another
                    > problem. Condensing steam in a tiny tube is a lot quicker than doing
                    > it in a big tube.
                    > An interesting aspect of Paynes original patent is using the momentum
                    > of the returning water to compress the remaining steam in the boiler.
                    > This should raise the boiling point so the steam has more kick to it.
                    > If this effect is significant I have no idea.
                    > More important I suspect is to have a forward facing intake and
                    > valves.
                    > Also, what about an output nozzle? you can significantly increase the
                    > velocity of water coming out of a hosepipe by sticking your finger
                    > over the end.
                    > This would also increase the pressure in the boiler and give the
                    > whole thing more go?
                    >

                    This is basically a bit of fun in the bathtub. But if Payne missed
                    something big, as well he might, then we aren't going to find it in this
                    kind of conversation, entertaining as it is.

                    We are talking about a resonant system involving an air spring of unknown
                    size, ever-reversing heat flow, the properties of steam and water under
                    rapidly varying pressure, and the movement of a heavy craft at low speed
                    under tiny fluctuating loads. There is virtually no experimental data, and
                    few if any of our members have either the maths, the mechanics or the
                    thermodynamics to discuss any part of it at a theoretical level. Despite
                    the simplicity of the device, it is vastly more complicated than, say, an
                    ordinary three cylinder compound marine steam engine. It has been usefully
                    demonstrated by Payne that when scaled up in a simple manner the power
                    required became enormous yet the result remained pathetic.

                    What would be needed to improve on that would be a set of experiments in
                    which every part of the apparatus had rapid-acting pressure and temperature
                    sensors, backed up an ever more sophisticated non-linear computer "model"
                    based on real thermodynamics until the whole process was understood.

                    The exciting thing is that this is actually all within the scope of a smart
                    pensioner with modest means.

                    Meanwhile, the complexity is such that the best answer to questions about
                    valves and nozzles is still "Try it!" (Please.)

                    David 1/2d
                  • Richard Mundy
                    Hi Matt, good to hear from you, I remember something similar using a wheelchair. Quite exiting for the occupier of the wheelchair,but it was all over quite
                    Message 9 of 29 , Jan 21, 2009
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                      Hi Matt, good to hear from you,

                      I remember something similar using a wheelchair. Quite exiting for
                      the occupier of the wheelchair,but it was all over quite quickly.
                      Problem with a boat is it won't go any spead unless you can get it on
                      the plane, which takes a lot of energy! The boat needs to be lifted
                      out and placed on top of the water.
                      Even I am not optimistic enough to expect to get a pop pop to plane.

                      Dick

                      --- In pop-pop-steamboats@yahoogroups.com, "Sparks, Matthew -
                      McClatchy Corporate" <msparks@...> wrote:
                      >
                      > If you really want to see what you're up against, check out the
                      > mythbusters episode where they took a fiberglass speedboat hull and
                      > mounted two of the large compressed air cylineders.
                      >
                      > http://televizzle.org/2006/12/06/air-cylinder-rocket/
                      >
                      > Matt Sparks -
                      >
                      > -----Original Message-----
                      > From: pop-pop-steamboats@yahoogroups.com
                      > [mailto:pop-pop-steamboats@yahoogroups.com] On Behalf Of Richard
                      Mundy
                      > Sent: Tuesday, January 20, 2009 2:03 PM
                      > To: pop-pop-steamboats@yahoogroups.com
                      > Subject: [pop-pop-steamboats] Re: Peter R Payne and proper boats.
                      >
                      > Hi David,
                      > I think the condensing is done in the tube, which creates another
                      > problem. Condensing steam in a tiny tube is a lot quicker than
                      doing
                      > it in a big tube.
                      > An interesting aspect of Paynes original patent is using the
                      momentum
                      > of the returning water to compress the remaining steam in the
                      boiler.
                      > This should raise the boiling point so the steam has more kick to
                      it.
                      > If this effect is significant I have no idea.
                      > More important I suspect is to have a forward facing intake and
                      > valves.
                      > Also, what about an output nozzle? you can significantly increase
                      the
                      > velocity of water coming out of a hosepipe by sticking your finger
                      > over the end.
                      > This would also increase the pressure in the boiler and give the
                      > whole thing more go?
                      >
                      > Dick
                      >
                      >
                      >
                      > --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
                      > <dh1@> wrote:
                      > >
                      > >
                      > >
                      > > --------------------------------------------------
                      > > From: "Richard Mundy" <coracles18@>
                      > > Sent: Tuesday, January 20, 2009 7:44 PM
                      > >
                      > > > As the engines grow bigger there is a need to create a lot of
                      > steam a
                      > > > lot faster.
                      > >
                      > > AND then condense a tube-full of it in a similar time, in the
                      very
                      > boiler
                      > > you have just heated it in!
                      > >
                      > > That is exactly the snag that Newcomen had - though with much
                      less
                      > thermal
                      > > capacity to heat and cool each pulse.
                      > >
                      > > David 1/2d
                      > >
                      >
                      >
                      >
                      > ------------------------------------
                      >
                      > Yahoo! Groups Links
                      >
                    • Richard Mundy
                      Hi Jean-Yves, you keep knocking down my skittles:-). Seriously, I value your input hugely. Apart from a few experiments perhaps 10 years ago, I am coming at
                      Message 10 of 29 , Jan 21, 2009
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                        Hi Jean-Yves,
                        you keep knocking down my skittles:-).
                        Seriously, I value your input hugely. Apart from a few experiments
                        perhaps 10 years ago, I am coming at this subject from a 'what if'
                        angle. I remember my biscuit tin/blow lamp boat moved forwards then a
                        little back per cycle. So there is a slight reverse pull on the
                        intake. I suspect tho that that the valves unless very carefully
                        designed would further reduce efficiency and as you suggest make the
                        forward facing inlet pointless.

                        On the subject of nozzles, I have no experience, I just wondered if
                        it had been tried.

                        Conventional boilers work at high pressure so the steam can hold more
                        energy. In a pop pop the boiler is, via the water, open to the
                        atmosphere. effectively like a kettle, and the steam produced is very
                        rapidly condensed by contact with the water and the unlagged exit
                        tube. All this accounts for at least some of the inefficiency of the
                        pop pop, hence throttling the output to up the pressure and speed up
                        the output flow. But will it still work? If it actually reduces
                        efficiency, why?

                        Dick


                        --- In pop-pop-steamboats@yahoogroups.com, "Jean-Yves Renaud"
                        <boite.de.j-y@...> wrote:
                        >
                        > Hi Dick,
                        > I would like to comment 2 topics of your last post: facing intake
                        and
                        > nozzle.
                        > 1°) Facing intake.
                        > Everybody thinks at the beginning that using a facing intake (and
                        > valves) could improve the performance of pop-pop propulsion. Even
                        > Peter Payne thought that. But facing intake is useless, or more
                        > exactly so inefficient that it becomes useless.
                        > • By math demo it can be proven that the effect of such a
                        > modification is negligible.
                        > • For those who dislike math, there is an easy way to check
                        > that sucking is far less efficient than blowing. Try to blow a
                        candle
                        > by sucking air!
                        > • In addition, to prove this inefficiency, 2 years ago I built
                        > a small boat with an electric pump to show that sucking water on
                        the
                        > bow has a negligible impact; though a jet backward propels. The
                        > pulling force (when sucking) was roughly 20 millions times weaker
                        > than the pushing one.
                        > 2°) Nozzle.
                        > The thrust of a waterjet evolving with the square of the velocity
                        of
                        > the water that is expelled it seems evident that a nozzle could
                        > improve the performance. However, on a pop-pop engine a nozzle acts
                        > also on the frequency, stroke volume…and this is detrimental. We
                        > don't know enough to give precise figures, but it seems that the
                        best
                        > nozzle has a diameter reduced by only 5 to 10%. On this forum Daryl
                        > is very likely the one who has got the best practical knowledge on
                        > this topic. Most of his engines are provided with nozzles and his
                        > engines are among the best ones if not the best.
                        > Jean-Yves
                        >
                        >
                        > --- In pop-pop-steamboats@yahoogroups.com, "Richard Mundy"
                        > <coracles18@> wrote:
                        > >
                        > > Hi David,
                        > > I think the condensing is done in the tube, which creates another
                        > > problem. Condensing steam in a tiny tube is a lot quicker than
                        > doing
                        > > it in a big tube.
                        > > An interesting aspect of Paynes original patent is using the
                        > momentum
                        > > of the returning water to compress the remaining steam in the
                        > boiler.
                        > > This should raise the boiling point so the steam has more kick to
                        > it.
                        > > If this effect is significant I have no idea.
                        > > More important I suspect is to have a forward facing intake and
                        > > valves.
                        > > Also, what about an output nozzle? you can significantly increase
                        > the
                        > > velocity of water coming out of a hosepipe by sticking your
                        finger
                        > > over the end.
                        > > This would also increase the pressure in the boiler and give the
                        > > whole thing more go?
                        > >
                        > > Dick
                        > >
                        > >
                        > >
                        > > --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
                        > > <dh1@> wrote:
                        > > >
                        > > >
                        > > >
                        > > > --------------------------------------------------
                        > > > From: "Richard Mundy" <coracles18@>
                        > > > Sent: Tuesday, January 20, 2009 7:44 PM
                        > > >
                        > > > > As the engines grow bigger there is a need to create a lot of
                        > > steam a
                        > > > > lot faster.
                        > > >
                        > > > AND then condense a tube-full of it in a similar time, in the
                        > very
                        > > boiler
                        > > > you have just heated it in!
                        > > >
                        > > > That is exactly the snag that Newcomen had - though with much
                        > less
                        > > thermal
                        > > > capacity to heat and cool each pulse.
                        > > >
                        > > > David 1/2d
                        > > >
                        > >
                        >
                      • Richard Mundy
                        Hi David, thanks for putting this into perspective, this is entirely for fun and is a subject that can be tinkered with indefinately, but as Jean- Yves points
                        Message 11 of 29 , Jan 21, 2009
                        • 0 Attachment
                          Hi David,
                          thanks for putting this into perspective, this is entirely for fun
                          and is a subject that can be tinkered with indefinately, but as Jean-
                          Yves points out, the likelyhood of a high powered big pop pop is very
                          slim.
                          Time to start torturing metal!!

                          Dick

                          --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
                          <dh1@...> wrote:
                          >
                          > --------------------------------------------------
                          > From: "Richard Mundy" <coracles18@...>
                          > Sent: Tuesday, January 20, 2009 10:02 PM
                          > To: <pop-pop-steamboats@yahoogroups.com>
                          > Subject: [pop-pop-steamboats] Re: Peter R Payne and proper boats.
                          >
                          > > Hi David,
                          > > I think the condensing is done in the tube, which creates another
                          > > problem. Condensing steam in a tiny tube is a lot quicker than
                          doing
                          > > it in a big tube.
                          > > An interesting aspect of Paynes original patent is using the
                          momentum
                          > > of the returning water to compress the remaining steam in the
                          boiler.
                          > > This should raise the boiling point so the steam has more kick to
                          it.
                          > > If this effect is significant I have no idea.
                          > > More important I suspect is to have a forward facing intake and
                          > > valves.
                          > > Also, what about an output nozzle? you can significantly increase
                          the
                          > > velocity of water coming out of a hosepipe by sticking your finger
                          > > over the end.
                          > > This would also increase the pressure in the boiler and give the
                          > > whole thing more go?
                          > >
                          >
                          > This is basically a bit of fun in the bathtub. But if Payne missed
                          > something big, as well he might, then we aren't going to find it in
                          this
                          > kind of conversation, entertaining as it is.
                          >
                          > We are talking about a resonant system involving an air spring of
                          unknown
                          > size, ever-reversing heat flow, the properties of steam and water
                          under
                          > rapidly varying pressure, and the movement of a heavy craft at low
                          speed
                          > under tiny fluctuating loads. There is virtually no experimental
                          data, and
                          > few if any of our members have either the maths, the mechanics or
                          the
                          > thermodynamics to discuss any part of it at a theoretical level.
                          Despite
                          > the simplicity of the device, it is vastly more complicated than,
                          say, an
                          > ordinary three cylinder compound marine steam engine. It has been
                          usefully
                          > demonstrated by Payne that when scaled up in a simple manner the
                          power
                          > required became enormous yet the result remained pathetic.
                          >
                          > What would be needed to improve on that would be a set of
                          experiments in
                          > which every part of the apparatus had rapid-acting pressure and
                          temperature
                          > sensors, backed up an ever more sophisticated non-linear
                          computer "model"
                          > based on real thermodynamics until the whole process was understood.
                          >
                          > The exciting thing is that this is actually all within the scope of
                          a smart
                          > pensioner with modest means.
                          >
                          > Meanwhile, the complexity is such that the best answer to questions
                          about
                          > valves and nozzles is still "Try it!" (Please.)
                          >
                          > David 1/2d
                          >
                        • David Halfpenny
                          ... From: Richard Mundy Sent: Wednesday, January 21, 2009 7:31 PM ... That s the spirit! D
                          Message 12 of 29 , Jan 21, 2009
                          • 0 Attachment
                            --------------------------------------------------
                            From: "Richard Mundy" <coracles18@...>
                            Sent: Wednesday, January 21, 2009 7:31 PM

                            > Time to start torturing metal!!
                            >
                            That's the spirit! D
                          • Jean-Yves Renaud
                            Dick, your biscuit tin/blow lamp boat moved back and forth (more or less as every pop-pop boat) not because of the suction, but because of the inertia of the
                            Message 13 of 29 , Jan 22, 2009
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                              Dick, your biscuit tin/blow lamp boat moved back and forth (more or
                              less as every pop-pop boat) not because of the suction, but because
                              of the inertia of the water contained inside the pipes.
                              It very easy to demonstrate that the suction is not the cause. On a
                              classic pop-pop boat with two pipes, just bend one on port and the
                              other one on starboard. Thus, there will be no more thrust (port and
                              starboard being equal and opposite). The boat will no longer progress
                              forward, but it will go on vibrating back and forth as before.
                              If you have a single pipe engine, just bend the outlet vertically
                              downward and the result will be the same.
                              Jean-Yves



                              --- In pop-pop-steamboats@yahoogroups.com, "Richard Mundy"
                              <coracles18@...> wrote:
                              >
                              > Hi Jean-Yves,
                              > you keep knocking down my skittles:-).
                              > Seriously, I value your input hugely. Apart from a few experiments
                              > perhaps 10 years ago, I am coming at this subject from a 'what if'
                              > angle. I remember my biscuit tin/blow lamp boat moved forwards then
                              a
                              > little back per cycle. So there is a slight reverse pull on the
                              > intake. I suspect tho that that the valves unless very carefully
                              > designed would further reduce efficiency and as you suggest make
                              the
                              > forward facing inlet pointless.
                              >
                              > On the subject of nozzles, I have no experience, I just wondered if
                              > it had been tried.
                              >
                              > Conventional boilers work at high pressure so the steam can hold
                              more
                              > energy. In a pop pop the boiler is, via the water, open to the
                              > atmosphere. effectively like a kettle, and the steam produced is
                              very
                              > rapidly condensed by contact with the water and the unlagged exit
                              > tube. All this accounts for at least some of the inefficiency of
                              the
                              > pop pop, hence throttling the output to up the pressure and speed
                              up
                              > the output flow. But will it still work? If it actually reduces
                              > efficiency, why?
                              >
                              > Dick
                              >
                              >
                              > --- In pop-pop-steamboats@yahoogroups.com, "Jean-Yves Renaud"
                              > <boite.de.j-y@> wrote:
                              > >
                              > > Hi Dick,
                              > > I would like to comment 2 topics of your last post: facing intake
                              > and
                              > > nozzle.
                              > > 1°) Facing intake.
                              > > Everybody thinks at the beginning that using a facing intake (and
                              > > valves) could improve the performance of pop-pop propulsion. Even
                              > > Peter Payne thought that. But facing intake is useless, or more
                              > > exactly so inefficient that it becomes useless.
                              > > • By math demo it can be proven that the effect of such a
                              > > modification is negligible.
                              > > • For those who dislike math, there is an easy way to check
                              > > that sucking is far less efficient than blowing. Try to blow a
                              > candle
                              > > by sucking air!
                              > > • In addition, to prove this inefficiency, 2 years ago I built
                              > > a small boat with an electric pump to show that sucking water on
                              > the
                              > > bow has a negligible impact; though a jet backward propels. The
                              > > pulling force (when sucking) was roughly 20 millions times weaker
                              > > than the pushing one.
                              > > 2°) Nozzle.
                              > > The thrust of a waterjet evolving with the square of the velocity
                              > of
                              > > the water that is expelled it seems evident that a nozzle could
                              > > improve the performance. However, on a pop-pop engine a nozzle
                              acts
                              > > also on the frequency, stroke volume…and this is detrimental. We
                              > > don't know enough to give precise figures, but it seems that the
                              > best
                              > > nozzle has a diameter reduced by only 5 to 10%. On this forum
                              Daryl
                              > > is very likely the one who has got the best practical knowledge
                              on
                              > > this topic. Most of his engines are provided with nozzles and his
                              > > engines are among the best ones if not the best.
                              > > Jean-Yves
                              > >
                              > >
                              > > --- In pop-pop-steamboats@yahoogroups.com, "Richard Mundy"
                              > > <coracles18@> wrote:
                              > > >
                              > > > Hi David,
                              > > > I think the condensing is done in the tube, which creates
                              another
                              > > > problem. Condensing steam in a tiny tube is a lot quicker than
                              > > doing
                              > > > it in a big tube.
                              > > > An interesting aspect of Paynes original patent is using the
                              > > momentum
                              > > > of the returning water to compress the remaining steam in the
                              > > boiler.
                              > > > This should raise the boiling point so the steam has more kick
                              to
                              > > it.
                              > > > If this effect is significant I have no idea.
                              > > > More important I suspect is to have a forward facing intake and
                              > > > valves.
                              > > > Also, what about an output nozzle? you can significantly
                              increase
                              > > the
                              > > > velocity of water coming out of a hosepipe by sticking your
                              > finger
                              > > > over the end.
                              > > > This would also increase the pressure in the boiler and give
                              the
                              > > > whole thing more go?
                              > > >
                              > > > Dick
                              > > >
                              > > >
                              > > >
                              > > > --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
                              > > > <dh1@> wrote:
                              > > > >
                              > > > >
                              > > > >
                              > > > > --------------------------------------------------
                              > > > > From: "Richard Mundy" <coracles18@>
                              > > > > Sent: Tuesday, January 20, 2009 7:44 PM
                              > > > >
                              > > > > > As the engines grow bigger there is a need to create a lot
                              of
                              > > > steam a
                              > > > > > lot faster.
                              > > > >
                              > > > > AND then condense a tube-full of it in a similar time, in the
                              > > very
                              > > > boiler
                              > > > > you have just heated it in!
                              > > > >
                              > > > > That is exactly the snag that Newcomen had - though with much
                              > > less
                              > > > thermal
                              > > > > capacity to heat and cool each pulse.
                              > > > >
                              > > > > David 1/2d
                              > > > >
                              > > >
                              > >
                              >
                            • Richard Mundy
                              Hi Jean-Yves, Yet another thing to think about. I had thought about momentum of the water column, but not its inertia. Dick ... and ... progress ...
                              Message 14 of 29 , Jan 23, 2009
                              • 0 Attachment
                                Hi Jean-Yves,

                                Yet another thing to think about. I had thought about momentum of the
                                water column, but not its inertia.

                                Dick



                                --- In pop-pop-steamboats@yahoogroups.com, "Jean-Yves Renaud"
                                <boite.de.j-y@...> wrote:
                                >
                                > Dick, your biscuit tin/blow lamp boat moved back and forth (more or
                                > less as every pop-pop boat) not because of the suction, but because
                                > of the inertia of the water contained inside the pipes.
                                > It very easy to demonstrate that the suction is not the cause. On a
                                > classic pop-pop boat with two pipes, just bend one on port and the
                                > other one on starboard. Thus, there will be no more thrust (port
                                and
                                > starboard being equal and opposite). The boat will no longer
                                progress
                                > forward, but it will go on vibrating back and forth as before.
                                > If you have a single pipe engine, just bend the outlet vertically
                                > downward and the result will be the same.
                                > Jean-Yves
                                >
                                >
                                >
                                > --- In pop-pop-steamboats@yahoogroups.com, "Richard Mundy"
                                > <coracles18@> wrote:
                                > >
                                > > Hi Jean-Yves,
                                > > you keep knocking down my skittles:-).
                                > > Seriously, I value your input hugely. Apart from a few
                                experiments
                                > > perhaps 10 years ago, I am coming at this subject from a 'what
                                if'
                                > > angle. I remember my biscuit tin/blow lamp boat moved forwards
                                then
                                > a
                                > > little back per cycle. So there is a slight reverse pull on the
                                > > intake. I suspect tho that that the valves unless very carefully
                                > > designed would further reduce efficiency and as you suggest make
                                > the
                                > > forward facing inlet pointless.
                                > >
                                > > On the subject of nozzles, I have no experience, I just wondered
                                if
                                > > it had been tried.
                                > >
                                > > Conventional boilers work at high pressure so the steam can hold
                                > more
                                > > energy. In a pop pop the boiler is, via the water, open to the
                                > > atmosphere. effectively like a kettle, and the steam produced is
                                > very
                                > > rapidly condensed by contact with the water and the unlagged exit
                                > > tube. All this accounts for at least some of the inefficiency of
                                > the
                                > > pop pop, hence throttling the output to up the pressure and speed
                                > up
                                > > the output flow. But will it still work? If it actually reduces
                                > > efficiency, why?
                                > >
                                > > Dick
                                > >
                                > >
                                > > --- In pop-pop-steamboats@yahoogroups.com, "Jean-Yves Renaud"
                                > > <boite.de.j-y@> wrote:
                                > > >
                                > > > Hi Dick,
                                > > > I would like to comment 2 topics of your last post: facing
                                intake
                                > > and
                                > > > nozzle.
                                > > > 1°) Facing intake.
                                > > > Everybody thinks at the beginning that using a facing intake
                                (and
                                > > > valves) could improve the performance of pop-pop propulsion.
                                Even
                                > > > Peter Payne thought that. But facing intake is useless, or more
                                > > > exactly so inefficient that it becomes useless.
                                > > > • By math demo it can be proven that the effect of such a
                                > > > modification is negligible.
                                > > > • For those who dislike math, there is an easy way to check
                                > > > that sucking is far less efficient than blowing. Try to blow a
                                > > candle
                                > > > by sucking air!
                                > > > • In addition, to prove this inefficiency, 2 years ago I built
                                > > > a small boat with an electric pump to show that sucking water
                                on
                                > > the
                                > > > bow has a negligible impact; though a jet backward propels. The
                                > > > pulling force (when sucking) was roughly 20 millions times
                                weaker
                                > > > than the pushing one.
                                > > > 2°) Nozzle.
                                > > > The thrust of a waterjet evolving with the square of the
                                velocity
                                > > of
                                > > > the water that is expelled it seems evident that a nozzle could
                                > > > improve the performance. However, on a pop-pop engine a nozzle
                                > acts
                                > > > also on the frequency, stroke volume…and this is detrimental.
                                We
                                > > > don't know enough to give precise figures, but it seems that
                                the
                                > > best
                                > > > nozzle has a diameter reduced by only 5 to 10%. On this forum
                                > Daryl
                                > > > is very likely the one who has got the best practical knowledge
                                > on
                                > > > this topic. Most of his engines are provided with nozzles and
                                his
                                > > > engines are among the best ones if not the best.
                                > > > Jean-Yves
                                > > >
                                > > >
                                > > > --- In pop-pop-steamboats@yahoogroups.com, "Richard Mundy"
                                > > > <coracles18@> wrote:
                                > > > >
                                > > > > Hi David,
                                > > > > I think the condensing is done in the tube, which creates
                                > another
                                > > > > problem. Condensing steam in a tiny tube is a lot quicker
                                than
                                > > > doing
                                > > > > it in a big tube.
                                > > > > An interesting aspect of Paynes original patent is using the
                                > > > momentum
                                > > > > of the returning water to compress the remaining steam in the
                                > > > boiler.
                                > > > > This should raise the boiling point so the steam has more
                                kick
                                > to
                                > > > it.
                                > > > > If this effect is significant I have no idea.
                                > > > > More important I suspect is to have a forward facing intake
                                and
                                > > > > valves.
                                > > > > Also, what about an output nozzle? you can significantly
                                > increase
                                > > > the
                                > > > > velocity of water coming out of a hosepipe by sticking your
                                > > finger
                                > > > > over the end.
                                > > > > This would also increase the pressure in the boiler and give
                                > the
                                > > > > whole thing more go?
                                > > > >
                                > > > > Dick
                                > > > >
                                > > > >
                                > > > >
                                > > > > --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny"
                                > > > > <dh1@> wrote:
                                > > > > >
                                > > > > >
                                > > > > >
                                > > > > > --------------------------------------------------
                                > > > > > From: "Richard Mundy" <coracles18@>
                                > > > > > Sent: Tuesday, January 20, 2009 7:44 PM
                                > > > > >
                                > > > > > > As the engines grow bigger there is a need to create a
                                lot
                                > of
                                > > > > steam a
                                > > > > > > lot faster.
                                > > > > >
                                > > > > > AND then condense a tube-full of it in a similar time, in
                                the
                                > > > very
                                > > > > boiler
                                > > > > > you have just heated it in!
                                > > > > >
                                > > > > > That is exactly the snag that Newcomen had - though with
                                much
                                > > > less
                                > > > > thermal
                                > > > > > capacity to heat and cool each pulse.
                                > > > > >
                                > > > > > David 1/2d
                                > > > > >
                                > > > >
                                > > >
                                > >
                                >
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