Pop-pop engine

The driving pop-pop is an Engine steam being used for the Propulsion small Bateau X Jouet S.

Its denomination comes from the Onomatopée evoking the noise characteristic of its operation. This boat or engine thus has variable names according to the languages: Pop-pop (English), Knatterboot, PPP, Puff-Paff, Tap-tap (German) or PPP, phut-phut, pouet-pouet, Edge-Edge-boot

Principle of operation

One can consider that the pop-pop engine is a kind of Chaudière to vapor of which dilation is used to expel the water of a control and which its Condensation is used to aspire water, by the depression created, in same control. The result of the operation of a cycle is that the boat advances. Why? The opinions differ. Some go even until advancing that it is only because, the boat being pointed in front of and broad with the back, the difference in penetration in water between walk-before and theback one explains that the Bateau advances. But those which saw one limps of preserve tuna transformed into pop-pop motor boat to advance, will be able to testify that this explanation cannot be scientifically correct, since invalidated by the experiment.

Before of to detail operation, it is necessary to know that the inventive initial names Désiré Thomas Piot , which, whereas it was London, deposited two Brevet S n°20081 (in 1891) and n°26823 (in 1897). This French engineer, Generating specialist in S electric, illustrated himself with the Concours Lépine, and its first notorious action in “pop-pop technology” is an patent application on an improvement of the steam boilers. It seems however if little convinced by its invention that it mentions that its engine could be used with the propulsion of toys.

The engine is consisted a serpentine, container of water, is heated by a source of heat. The two ends of the serpentine lead to the poop (back) of the boat under the level of the floating. The serpentine must be filled of water before the starting of the engine. If the engine is correctly produced, it stops only with the extinction of the hearth.

In 1924, C.J. Mc Hugh took in America the patent n° 1,598,934 (June 1924). It consisted in improving the invention of the engineer Piot , by creating a room of evaporation provided with a flexible membrane at its upper part. Even if certain specialists in pop-pop technology disparage this artifice which would decrease according to them the output of the machine, the noise generated by this flexible capsule is at the origin of the name thepop one, the Piot engine being almost quiet.

We can thus consider that the scientific name of the pop-pop engine is the driving Piot-Hugh . But this name had little echo in the scientific press.

Diagram 1 represents a traditional pop-pop engine. One can carry it out with only one Tuyère, the result is similar but the filling of the evaporator with water is more complex. It is necessary to have a Seringue for emptying the air well. Aesthetically speaking, the models with two conduits are perfect, the noise is identical to the same engine equipped with only one conduit.

The principle of operation a priori

As we saw higher, it is about a boiler , consisted space between two metal plates, on which two tubes of low diameter are connected. The end of the two tubes is immersed in water with the back of the boat. A source of heat (candle, alcohol) heating regularly the boiler.

On the basis of attentive observation of the users, then after having tested oneself, one can deduce some too quickly whom it is enough to start the process by introducing water into one to the tubes, to pose the boat on water and to place the source of heat under the boiler. From starting, the heated air escapes by the free tube which offers a less resistance, involving by aspiration of water in the boiler. The latter, range with boiling escapes in her turn by the same way (see diagram 2), creating a force of reaction which advances the boat. This circuit remains as much as the source of heat is in work.

It is almost true. This description of operation appeared in Driving article the “in opened boiler”, by analogy with the boilers or the engines functioning in open medium. However the engine also functions if it is provided only with only one conduit. It is thus not a water circulation in an one way which causes the propelling reaction.

The true principle of operation

Diagram 3 represents a cut of a unit boat-boiler-pipe (S).

Some experts in Thermodynamic, mechanics of the fluids, and engines with Réaction are leaning on pop-pop technology. Among those we can refer seriously to the scientific work, tests, measurements and theoretical calculations carried out by a professional of naval construction and maritime propulsion.

It comes out from it, after in-depth study, that it is easier to define how does not work a pop-pop engine, to specify its true operation. However a consensus seems to emerge among the very sizeable engineers who, without assistance nor subsidy, carried out long and expensive tests, with the danger from their life (burns, explosions) but in the creditable spirit to advance science. Therefore, on the basis of a certain number of observations which can be reproduced by any person equipped with a testing ground (a tank, a tank, a bath-tub etc), one can check that:

the pop-pop boat does not advance if the conduits are stopped. They are thus neither the noise nor the vibrations which propel it.
the pop-pop boat burns or melts, explodes or runs if one lays out the conduits with the top of the water line. It expels almost blow the water becoming ebullient of which one filled the circuit, then stops, even if the conduit is bent of kind to retain a little water.
the pop-pop boat does not advance if one directs the conduits on the side instead of leaving them logically directed towards the back. One could suspect it, this proves that there is a phenomenon of reaction. If the conduit is reversed it moves back.
the pop-pop advance with only one conduit, it thus does not have there water circulation in only one direction. It is not a boat Hydrojet.
If one prevents the boat from advancing, it exerts, at the fixed point, light thorough. They are thus not the currents created on the water level by perverts heating effects or mechanics which advances it.
a simple serpentine can replace the system with membrane. Pop-pop advance, but without noise. Contrary to the famous motor bike, it is thus not the exhaust which makes pop-pop, but the membrane.
After the period of startup, a few seconds, the noise becomes regular, at a frequency of some Herz. There are thus a launching phase and a mode of cruising.
If one heats too extremely, the pop-pop engine has hoquets which are symptomatic of an operation in perpetual mode of starting.
When the source of heat dies out the engine stops as from the moment when the wick of the candle is not incandescent any more.

All these observations, and still well of others which it would be tiresome to enumerate here, associated with the computation results with thermodynamics not being able to be disputed, make it possible to consider, with all the precautions which are essential, that the typical operation of the pop-pop engine can be defined as follows:

After filling of the circuit by water, while avoiding leaving air there what would delay its normal functioning, or even would properly make it be choked with starting, and after having lit the candle, or the “méta”, to have delicately deposited it on the surface of the water level, the heat of the candle would be communicated to the tank (with the tank provided with the membrane), which would create vapor which would push the water of the tank and part of that of the pipe to the outside. Initially.
the depression created by the projection of this water tube, combined with that generated by the cooling of the vapor overheated out of saturated vapor, réaspirerait of water in the conduit (or the conduits), in the second time, part of saturated vapor being then overheated what would recreate the first time.

The pop-pop engine is of this fact an alternate engine two times with external combustion with vapor with diphasic heat exchange.

Knowing what makes noise, the membrane, knowing that a water tube carries out a to and from in the conduit, the problem of the propulsion therefore is not cleared up of it. On this point the divergent opinion:

One can consider that water is ejected more quickly than it is not réaspirée. The kinetic difference of energy would create the propulsion.
One can, like the majority of the specialists, to estimate that water is aspired in all the directions whereas it is rejected only into the opposite direction of walk. There would be thus a reactive effect of front walk to expulsion, a less reactive effect of step back to the aspiration.

One can as adopt a neutral position and wish as in the future thorough experimental research will make it possible to raise the doubt.

Last developments, patents and registered trademarks

One will be able to consult a list of the patents deposited.
the name of “pop-pop motor boat” was deposited with INPI the 10/26/1995 under N° 95595116 and belongs to the Hardware store of Navy .

Construction amateur

Even if one can rather easily get a pop-pop boat ready with employment, it is amusing to build it oneself.

It seems however advisable to remember that these toys can prove dangerous , because they burn , and do not have to be left between all the hands.

Manufacturers, distribution

The principal building sites are located in India. The raw material used for the hull is the tinplate, sometimes brass for the tank of the boiler and piping. One can get some easily in line, some stores of toys and certain tobacconist's shops.

Competitions

The great competition of motor boats pop-pop, known as Championnat of the world of Loguivy-of-the-Sea of pop-pop motor boats proceeds each year with Loguivy-of-the-Sea ( Ploubazlanec).

See too

External bonds

Constructions amateur:

a personal site
Another personal site

References

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