what material?

[stq]

i am new to this sport and was wondering what is the best material for a valveless pulsejet. I want t build one that is not more than 45cm long, can i use copper or is stainless steel a must ? if the jet works well i might put it on my model aircraft.So will copper be reliable enough

[Mark]

If nothing else, you can make the most beautiful blue-green flame. Copper is pretty borderline, but good for a prototype I suppose. Maybe you could keep it cool with a water bath or just a flow of water over the copper. Copper conducts heat very well, thus of course used in pots and pans and other interesting applications.
Mark
http://www.copperheatsink.com/index.html
http://www.chemicalelements.com/elements/cu.html

[El-Kablooey]

How are you going to join the copper pieces together? Even silver solder will melt. Copper can be TIG welded pretty easily, but if you can TIG why not use SS??

[El-Kablooey]

How are you going to join the copper pieces together? Even silver solder will melt. Copper can be TIG welded pretty easily, but if you can TIG why not use SS??

[Mark]

While I haven't "ironed" out all the hurdles, or coppered them out rather, I have toyed with the idea of copper pulsejets. What I did for a good start was to file out the little teeth in the bells so that the 1/2 inch tubing could slide all the way through without hanging up. Then I flared the ends and reversed them, pulled them back the other way making a very tight seal.
One way to pull this off would be to use the copper bells with the threading at one end and use threaded copper nipples for a combustion chamber the same as you would do plumbing pipe, which I have honed to a science in several sizes. ha
There are neat little copper "clamps" that you could even use to hold your pulsejet down as pictured. You could also Everman/smash some larger diameter copper tubing, I have a length of some in which could easily be squashed into a typical puslejet shape without too much trouble using a bar to hold the shape of the tailpipe. Then it would look like a tailpipe with flanges on either side and the full shape retained for the combustion chamber.
Anyway, just some humble beginnings.
Mark

[Jim Berquist]

Expert I are Not! Some place in this forum I have seen people make valved and valveless P.J. Out of just about any thing you could imagine. Some one even made one out of wood that lasted a few seconds. Seems most materials of choice is mild steel or S.S. I only have access to a gas set up for welding so I have dabbled in mild steel...

Look around in the forum and you can't go wrong!. At worst you will see the blunders of the curious and lean some more from mistakes made by others...

There has been some really serious research and science done in here and much to learn .........




Jim

[stq]

i think ill just use mid steel as it will be more durable. But thanks for all the help guys