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Re: Peter R Payne and proper boats.

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  • 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 1 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 2 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 3 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 4 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 5 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 6 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 7 of 29 , Jan 21, 2009
                • 0 Attachment
                  --------------------------------------------------
                  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 8 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 9 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 10 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 11 of 29 , Jan 21, 2009
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                          --------------------------------------------------
                          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 12 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 13 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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