Please evaluate this design.

I'm trying to develop a new type of engine, but before deciding to make a prototype, which could take a long time, I would like you –who know more than I about motors– do tell me if my engine design has a serious impediment.

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Bill WW4 years ago
Here are some things to consider.

1. The engine is a big project. Perhaps the engine project should be separate from the boat project.
2. I did not understand the design of the conical boiler and conical displacer. However, the gif made this clear. The boiler has conical bottom. The displacer is the same conical shape. Correct?
3. Your design is not similar to Savery engine.
4. Your design may not be a Sterling cycle. Sterling cycle uses gas, not water vapor.
5. Your design may work fine, but will require much trial and error and more experiments.

Es fácil criticar. Es difícil crear.
Aquí están algunas cosas considerar.
1. El motor es un gran proyecto. Tal vez el proyecto del motor debe estar separado el proyecto del barco.
2. Que no entendía el diseño de la caldera cónica y desplazador cónica. Sin embargo, el gif dejado esto claro. La caldera tiene fondo cónico. El desplazador es la misma forma cónica. ¿Correcto?
3. El diseño no es similar al motor de Savery.
4. El diseño no puede ser un ciclo de Sterling. Ciclo Sterling utiliza gas, vapor de agua no.
5. Su diseño puede funcionar bien, pero requerirá mucho ensayo y error y más experimentos.

Con mucho gusto
rimar2000 (author)  Bill WW4 years ago
Bill, gracias por tus consejos.

1) Sí, el motor es la única cuestión aquí. El esquema del barco era sólo una referencia acerca del motor pop-pop.
2) En realidad la caldera será en forma de cono truncado, porque es más fácil de construir por medio de sheet metal spinning (no sé cómo se dice en castellano). El desplazador debe encajar exactamente en la caldera, con el fin de desplazar toda el agua de ella.
3) Tienes razón.
4) La parte Stirling de mi diseño es sólo el desplazador. El ciclo es totalmente diferente, más parecido al del pop-pop. Es realmente una combinación de ambos.
5) Del primer millón de dólares que me produzca el diseño, por lo menos 10 dólares te pertenecen.

Bill, thank for your advices.

1) Yes, the motor is the only matter here. The boat scheme was only a reference about pop-pop motor.
2) Really the boiler will be truncated cone shaped, because it is easier to build by means of sheet metal spinning. The displacer must fit exactly into the boiler, in order to displace all water of it.
3) You are right.
4) The Stirling part of my design is only the displacer. The cycle is totally different, more like pop-pop. It is really a combination of both.
5) On the first million dollars that will produce the design, at least $ 10 you belong.
Bill WW4 years ago
Osvaldo, the gif is now working and answers some questions.
nice work.

Osvaldo, el gif ahora está trabajando y responde a algunas preguntas.
Buen trabajo.
Bill WW4 years ago
Hola Osvaldo

Pop – Pop engine

The thrust from the engine is due to the high velocity of the steam exiting the pipe in rearward direction. The same amount (mass) of water enters and leaves the engine. However, the mass of water enters slowly, and after being vaporized, is forced back out at high velocity. It is similar to jet engine. Air is sucked into engine. Air is heated. Heated air expands and exits to rear at high velocity. In both cases (pop-pop and jet), the same mass enters and exits, however the mass exits at high velocity due to heating of the fluid. In case of pop-pop, the water is vaporized and the large volume of steam must exit rapidly.
Here is equation, force from jet of fluid:
F = Q ρD V
V= jet velocity m / s
ρ = fluid density, kg / m3
Q = flow rate, m3 / s


El empuje del motor es debido a la alta velocidad del vapor saliendo del tubo en dirección hacia atrás. La misma cantidad (masa) de agua entra y sale del motor. Sin embargo, la masa de agua entra lentamente y después de ser vaporizado, es expulsada nuevamente a alta velocidad. Es similar al motor de jet. El aire es aspirado en motor. Se calienta el aire. Aire caliente se expande y sale hacia atrás a velocidad alta. En ambos casos (pop-pop y chorros), la misma masa entra y sale, sin embargo la masa sale a gran velocidad debido al calentamiento del fluido. En caso de pop-pop, el agua se vaporiza y el gran volumen de vapor debe salir rápidamente.
Aquí está la ecuación, La fuerza del chorro de líquido:
F = Q ρD V
V = velocidad de chorro m / s
Ρ = densidad del fluido, kg / m3
Q = flujo tasa, m3 / s
rimar2000 (author)  Bill WW4 years ago
Bill, the water enters into the motor at high speed and high power too. It almost did a hole in my index finger when I was testing a pop-pop that had only one escape tube.

Furthermore, consider that if water enters slower, would longer, so the effect is the same (time is also involved in the thrust equation). I attach a crude drawing to illustrate that occurs. Anyway, this is not the knot of the matter.
Motor Pof-pof Escape.jpg
Bill WW4 years ago
Ostvaldo, aquí son mis comentarios del texto, solamente para corregir un poco palabras de Ingles. Manana mis ideas del proposito.
Here are my comments on the text; at this time only to correct a few words of English. Tomorrow I will give you my thoughts on the proposal.
rimar2000 (author)  Bill WW4 years ago
Thanks, Bill. I will download it to fix errors and re-upload the document.
rimar2000 (author)  rimar20004 years ago
Done, thanks. I uploaded the gif too. Here it works, that is "the computer's magic".
Bill WW4 years ago
Hola Senor Ostvaldo!

Very surprising, I am also designing and building a stirling cycle engine. But not too surprising, since we both seem to have similar interests (los locos).

I will review and comment on your design this week. In the meantime, please view this video of my first totally solar powered Stirling cycle engine:


Lo siento por solo Engles.

Tu Amigo,
rimar2000 (author)  Bill WW4 years ago
Hello Bill!

Very well done your Stirling motor! Last month I did one with rotary displacer, but I could not overcome the problems arising from the lack of precision. The rotor slightly touched the camera walls somewhere, and although I made a mechanism to tilt the shaft from outside, that could help very little. To make matters worse, when applying heat, the camera deformed a bit, visually imperceptible, but enough so that the friction would become insurmountable.

Stirling motors are awesome, but their power are very low. Instead, steam motors are very powerful. I pretend to combine both advantages. I admit that that is "low technology", but I love low technology. I think my design is very very simple, any boy with a minimum of interest and skills can make it.

I am wainting your opinion, hope you read my explanations and analyze my drawings before passing judgment.
Imprimí el documento, lo voy a estudiar.
¿Qué software se utiliza para traducir?
Yo quisera comprender El Espanol mejor.

I printed your document and will study it.
What software do you use to translate?
\I would like to understand Spanish much better.
rimar2000 (author)  Bill WW4 years ago
Yo uso Google Translator, pero luego de traducir tengo que revisar bien porque a veces omite un "no" o arma la frase como a él se le ocurre, con lo cual dice cualquier cosa menos lo que uno quiso decir. Pero yo conozco algo de inglés por haberlo visto en el colegio secundario, y además por haber trabajado en computación casi 38 años.

I use Google Translator, but then I have to revise translate well because sometimes omitted a "not" or the phrase gun as it comes up, which says anything but what you meant. But I know some English by seeing him in high school, and also having worked almost 38 years in computing.

My corrections:
I use Google Translator, but then I have to revise well because sometimes it omits a "not" or assemble the phrase as it want, whereupon says anything but what I meant. But I know some English by seeing it in high school, and also having worked almost 38 years in computing.
Kiteman4 years ago
You can upoad most kinds of file using the image uploader.

Just watch the size of video files.

Looking at your pop-pop motor, I don't think that will work. The boiled water moves out much further than your piston will allow.

Looking at your steam engine, I think you've effectively reinvented Thomas Savery's steam engine of 1698, which was rapidly superseded by other designs, not just because it could only lift water, because also because it was spectacularly inefficient.
rimar2000 (author)  Kiteman4 years ago
Kiteman, last night I saw what you say, I managed to upload the file without problems. Perhaps the editor should change the word "images" with "files", or clarify that feature.

My design is only a schema, not at all accurate in terms of sizes, so your statement "The boiled water moves out much further than your piston will allow" is very easily solved by increasing the diameter and/or travel of the piston. Those details are the salt of experimentation and adjustment.

I was watching the steam engine of Thomas Savery, I found it interesting but did had piston and spout to the outside, so it is not like mine.

Thanks for your response!