modular design: big Escopeta made of chimney pipe segments

[zono]

A cheap way to make valveless pulsejets

Various valveless pulsejets can be assembled and re-assembled by using oven- or stainless chimney pipes , fitted together with clamp-supports (clamp-belts). No additional welding is necessary. But take care of leak-tightness. Gaps must be sealed with high-temperature resistant material (i.e. glass fiber textiles)

These videos were taken by friends at "Days of Speed and Thunder" pulsejet meeting in Rothenburg/OL (Germany) in 2009 and 2010:

http://www.youtube.com/watch?v=e0mxQEiNPIM

http://www.youtube.com/watch?v=meLxHZsSXIU

http://www.youtube.com/watch?v=EZzAwuDEKA0

zono

[ace_fedde]

Modular, that would be my choice as well (but still didn't build anything ). Gives great possibilities for tweaking and experimenting.
I would use though (large, for cooling) flanges, bolted toghether with copper seals between them.

Will be, will be.....

Fedde

[Mark]

Did the linear pulsejet/straight pipe get tested and did it run or is there any footage? I noticed it still had a silvery appearance in the photos.

[zono]

Mark,

the linear pulsejet/straight pipe wasn't tested yet (it is a PDE pulse detonation engine). But I have a straight PJ design that is working fine (valveless "Schmidt-Rohr"). I will post it in some days.

zono

[metiz]

(it is a PDE pulse detonation engine)
zono

I'll eat my shorts if that's a working pde you'd be rich!

[zono]

metiz,

you are right, I didn't test this "PDE" until now, but

"Just you wait and see, Henry Higgins! Wait and see! "

....and obtain some Tabasco or ketchup, your shorts will taste better...

zono

[metiz]

just a friendly warning: if the stars align and you somehow manage to get it going (you'd be the first),when the engine does its first detonation, it'll also be the last. Your sheetsteel engine will explode into a million pieces likely killing you in the process. Any detonation engine (some have been made with realy complex, laboratory controlled material with a lot of moving parts) need to be made of a couple of cm thick tube, not mm, to stand the explosive forces.

So if you are REALY, REALY confident your engine will work, rig up a remote controll of some sort. if the engine explodes, you can pop the cork and then build a fatter version

[zono]

The Chapman-Jouguet pressure of stoiciometric propane-air mixture is only about 18 bars. Its not so much for my 2.5mm high alloy steel tube (the thin shiny one laying on the grass in my pictures). My design is valveless : for that reason pressure peaks should not reach full 18 bars.

zono

[metiz]

Hmm you seem to know your stuff. regardless, be carefull and post the results

[zono]

yes, i will use remote control or a long, long wire. Maybe it would be interesting for forum members to post a build blog of this PDE (some electronics are still missing; i.e. ignition drivers and solenoid valve controls)

[PyroJoe]

Indeed,
very interesting, I would like to see your build log in the PDE section, it is rather barren in actual attempts.
thanks, Joe

[zono]

for interested people in PDE stuff , I posted my PDE build blog here:

viewtopic.php?f=12&t=5924&start=0&st=0&sk=t&sd=a