Ozpulse, Symmetry series.

[Chadly33]

Have built a new engine, have run it at home tonight and seems to run well. Need to do some thrust tests as yet hopefully tommorow. I have shortened the nozzle which also opened the exhaust up a lot. I have taken some ideas from other engines on the forum but stuck with my exhaust design.

[Graham C. Williams]

Hi.

When it's running, you could try feeding some fuel, via a Rosscoinjector, into that exhaust pipe, just to see what happens?
My one concern is the amount of cold air drawn into the exhaust pipe. In ordinary designs it's this mass of air that provides the majority of the thrust. With this design you are limiting this airflow. I'm wondering if you can offset this by burning it in the tail? What this will do to the waves structure, in the pipe I couldn't say at the moment. The convergent tailpipe is sending a compression wave back into the combustion chamber, what would be the effect of increasing the amplitude of this wave?

Graham.

[metiz]

Looking slick, Chadly
video!

[Chadly33]

Ok! Shot a short Vid. of one of the first runs . It starts easily, and seems to have a decent amount of thrust. Though I still have to get it onto some scales and tune the injector position. All the welds are stainless mig welded and smoothed back so you cant actually see the joins , This is with 15thou injector( I started with a 20thou but it over fueled and flamed out) Now seems to get to full throttle and hold without flame out. Had to build a bigger mount for this one as the other was too light and resulted in a minor burn. Tattoo'ed again in the name of my passion!LOL

Enjoy!

Chadly.
http://au.youtube.com/watch?v=YIUPiCLi5zQ

[Mike Everman]

Very cool. That divergent-convergent tail is so bizarre, and works, and, and- faaaascinating. Though I would love to see:
A: thrust for this
B: thrust for the same combustor, but the tail merely diverges in a single cone from the throat you have to the exit diameter you have.

That is the test I would do to see if it is worth the extra volume.
Or just make it your trademark, as you have, and damn the torpedoes! ha

Good video.

[metiz]

It's always a good sign when the camera starts to move nice vid. I can't stop to think the intake could be bigger though...

[GRIM]

Hey Chadley, very nice engine and a great vid,
I have the feeling that another inlet may appear on the other side , sometime or the other
great stuff.

[Ghrey]

Beautiful as usual.

I think the tail design is brilliant. Keep going


Cheers....

[Chadly33]

Thanks guys! I do indeed intend to keep going with these design engines. The local hobby shop wants a couple to put in there for sale, they want them ready to go with ignition units etc. so I guess I will have my work cut out for me over the next couple of weeks! But of course there is always time to try new ideas as well.lol As far as the intake goes on this engine it seems to breath quite well so I will probably stay with the single just to keep fueling simple. The exhaust doesnt have that much more mass than a standard conical one, my idea is it takes the same larger mass(piston) of air and forces it to be blasted out the back at a slightly higher pressure and speed than a normal conical exhaust. As everyone seems to believe that PJ engine works right through its entirety this setup seemed to make complete sense to me, almost adding a second stage to the engine wich seems to help the flame retention at the higher pressure(fueling) stages as well as adding a positive feedback to the CC to help things out.

Cheers,

Chadly..

[Chadly33]

Thought I would post up a couple of pics of the completed setup as it will be in the hobby shop!

[Chadly33]

Just thought I would let you guys know that I have listed this complete setup on Ebay for sale if anyone was interested?? I wasnt sure what price to put on it so I just added up what it cost me and added $50 for my time. The running stand could be used for many motors of course and having the ignition,air all built in is a plus! Of course arrangements could be made for delivery to just about anywhere.

Cheers,
Chadly..

[Viv]

Chadly!

$50 bucks! that is way to cheap for the amount of work you have obviously put in to it, sets the bar a bit low don't ya think?

Viv