resonant combustor

[leo]

I hat this thing lying around for two months, no never expect it to get it started.
Some sort half of a BCVP.
First I tried it with two evenly short pipes, it would not self sustain.
Then with one longer pipe, it runs en starts reasonable easy.
Then I put more length on it and its start easily.
I don’t think there’s much trust, but that not important for this prove off concept.
Probably this thing is already invented, but I don’t know of it, for me its new.
It runs on 117 HZ regardless of the length of the long or shorter exhaust, the resonance is determinate by the long combustor/resonance pipe, witch has a length of 1806mm.
The resonant pipe stays cool on most of its length, it only gets hot on the combustion region.

Things to do are;
Make the same ports on the opposite end.
Get the exhaust pipe in sync with the resonance.

[El-Kablooey]

Crazy sound! That's pretty interesting, wonder what would happen with a duplicate setup on the other end of that big pipe.

[milisavljevic]

Hello Leo --

It runs on 117 HZ regardless of the length of the long or shorter exhaust, the resonance is determinate
by the long combustor/resonance pipe, witch has a length of 1806mm.

Interesting video! Do you have a dimensioned drawing of this setup that you can share?

Curious,
M.

[Graham C. Williams]

Dear Leo.
Nice work.
Some of the early BCVP motors would run in this strange mode. Viv called it the Lockwood mode. We'd shock start the thing and it would run just like that on one end. Could never get the other end to light up properly. The difference was we didn't have that short induction pipe; it might make the difference in your design.
I hope you keep going with this project.

Graham.

[leo]

Here is a picture of the parts I tried just had them laying around from previous experiments.
I made this combustor with the PCVB in mind, I had not a lot to go on, only the last section of the valveless section off this site.
One end of big pipe is closed, to simulate a second combustion region.

For all interested the internal measurements are;
Combustor/resonator length 1806 mm, diameter 73 mm.
Two inlet pipes length 100 mm, diameter 19 mm.
Exhaust pipe strait length 100 mm diameter 19 mm +
cone length 105 mm diameter 19 mm / 41 mm +
strait length 100 mm diameter 41 mm.
Short extension length 100 mm diameter 19 mm.
Long extension length 415 mm diameter 19 mm.

[milisavljevic]

Leo -- Thanks for the new information!

M.

[Jonny69]

Hi Leo I like the way you're hiding behind a bin and the way it appears to be started with a hammer and a hacksaw. Love the ghetto style! Keep up the good work! Intruiging design.

[leo]

I started the thing last Sunday, with the help of my brother (because it has to start on two sides simultaneous), but didn’t make a video.
Today I started it again with two air injectors, I could do it on my one.
It has to run on two sides else it will not self sustain
Maybe this thing will give the start to a new family of pulsejets,
Bruno do you mind if its called a BCVP, or has it not enough in common with your concept?.
The frequency has gone up to 140 HZ compared to the half combustor frequency off 117 HZ.
The exhaust pipe lengths in the video is 850 mm.

[Graham C. Williams]

Dear Leo.
Superb work. Join the club.
I don't think your getting much charge compression at the moment. You'll know when you do -no mistaking it. Still it's good to see.

Regards
Graham.

[milisavljevic]

The frequency has gone up to 140 HZ compared to the half combustor frequency off 117 HZ.

Leo -- Congratulations!

With a constant resonator length and a frequency rise of 19.7%, the acoustic temperature has increased by 43.2%.
What are you using for fuel? In your first video, there appears to be a propane (LPG) tank; can you confirm this?

You can always christen your creation "BCPC" (blast compression pulse combustor), as it is a not a propulsive duct.

Great work, Leo!
M.

[Nick]

Congratulations Leo!

nice work!

Cheers

Nick

[Bruno Ogorelec]

Bruno do you mind if its called a BCVP, or has it not enough in common with your concept?

Leo, BCVP is a description, not a proprietary name. I have 'my' BCVP actually filed as 'project SP-03'.

Feel free to use the BCVP tag for whatever you find appropriate.

[leo]

Update on this project, this is a movie off a month ago in a bent configuration.
You can see me take a stereo recording from the inlets here is a picture of the waves, its not very good-looking, but its prove that the are running out of phase.

I take it apart and made some big modifications, bigger intakes on other positions, bigger exhaust with cones, additional injectors.
Its first only would run on one side but started airless.
Then I made further modifications and started it again today, it started airless on one side easy but the other side needed a little air to start. Only could run it on low fuel flow because the propane tank was almost empty.
I have a problem with testing because of the noise, I live in the Netherlands, its very densely populated and hard to find a testing site far away from houses.
So I have to carefully plan my next move to keep testing minimum,
Also I have other far fetched ideas I’m working on.
I envy you guys in the VS and Australia, with space enough around, come to think of it almost every country would be better to test pulsejets.

[milisavljevic]

Hello Leo --

Update on this project, this is a movie off a month ago in a bent configuration.

Thanks for the update! To steal Mike's tag line (again! =) ... Faaaaassscinating!

You can see me take a stereo recording from the inlets here is a picture of the waves, its not very good-looking,
but its prove that the are running out of phase.

I'm no historian, but you appear to have recreated an Esnault-Pelterie ('push-pull') paired combustor. Very cool.

Best regards,
M.

Edit: corrected spelling of the name 'Esnault-Pelterie' -- thanks, Larry!

[Mike Everman]

Leeeeeo! That's beautiful! Ha ha That's almost worth buying a plane ticket to come see! Nice work.