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Re: PyroJoes Recipe for Beginners

Posted: Thu Mar 01, 2012 3:26 pm
by PyroJoe
Alot of variables in that one. Probably it matches your fuel source in a good way.

Re: PyroJoes Recipe for Beginners

Posted: Thu Mar 01, 2012 3:37 pm
by ganuganu
I forgot to ask you one thing, two days before i saw an image(it was in old posts) posted by you with grey background details of different valveless engine designs like russian, chinese, helmholtz and so on. I could remember everything what was there in that image before i could save the image there was a power shut down so couldnt save it. If you can please post it here i need that image file. It was really helpful to me. After seeing it i got some good amount of ideas.

Re: PyroJoes Recipe for Beginners

Posted: Thu Mar 01, 2012 3:50 pm
by PyroJoe
Hmmm I don't recall that one, were they lined up, or stacked one below the next?

Re: PyroJoes Recipe for Beginners

Posted: Thu Mar 01, 2012 3:54 pm
by ganuganu
designs were placed one below the other, there were nearly 10 or 11designs i think so.

Re: PyroJoes Recipe for Beginners

Posted: Thu Mar 01, 2012 4:25 pm
by PyroJoe
The recipe is built around much of that one. Now with the blended bodies explaining the valved engines wider body, I have added them into the same set. --CLICK TO ENLARGE-- :D

Re: PyroJoes Recipe for Beginners

Posted: Thu Mar 01, 2012 4:42 pm
by ganuganu
Thank you joe, thats great and i think you could add the old type thermojets also. engine shown in the pic.

ps: what does those colours represent

Re: PyroJoes Recipe for Beginners

Posted: Thu Mar 01, 2012 4:49 pm
by PyroJoe
Thanks I need a few more to reach 50.

Red is the extreme intake length. The purple on the left is where most chamber lengths stop or are mostly tapered down to the tailpipe. The right purple, is where most tailpipes start expanding. The blue represents some plus or minus length.

Re: PyroJoes Recipe for Beginners

Posted: Thu Mar 01, 2012 6:07 pm
by metiz
Cool graph!

Do you feel like the scientists who want to find a "unified theory of everything" now? :)

Btw, you can shoehorn the M25 in there if you want as well.

Re: PyroJoes Recipe for Beginners

Posted: Thu Mar 01, 2012 7:39 pm
by PyroJoe
glad you like it

Unified Theory, thats easy.... E=E ...done deal, ha

M25, will do!

Re: PyroJoes Recipe for Beginners

Posted: Fri Mar 02, 2012 12:59 pm
by ganuganu
photo of my modified engine with augmenter. Take a look at the picture. I will test it soon.

Re: PyroJoes Recipe for Beginners

Posted: Fri Mar 02, 2012 2:30 pm
by PyroJoe
The intake is a little short and the gap between the intake and augmenter looks big.
It may work ok though, give it a go.

One thing to look for is if most of the flow is collected by the augmenter, or if the exhaust plume is spreading before it enters the augmenter. One way to check is to feel for a positive pressure "puff" at the rim of the augmenter. Shown in the color blue. Whats happeing is the exhaust doesn't have the velocity/energy to drive the augmentor at that gap / distance. It will try to leak to the sides. This can also happen if the augmentors are very long.

Re: PyroJoes Recipe for Beginners

Posted: Fri Mar 02, 2012 2:42 pm
by ganuganu
Now the intake length is about 8cm can i increase it to 10cm, and the distance between them is about 6.9cm how much shall i decrease?

Re: PyroJoes Recipe for Beginners

Posted: Fri Mar 02, 2012 3:26 pm
by PyroJoe
I say try it first and see the results. That gap may not be any problem. Just to my eye, it looks wide. The gap is one of the things I have not determined an exact dimension.

Re: PyroJoes Recipe for Beginners

Posted: Fri Mar 02, 2012 3:41 pm
by PyroJoe
metiz, I forgot to mention a topic about the "back pressure" of the un expanded tail length.

When the pressure goes below normal, as seen earlier in purple, the tail will continue to pull in more air.
So in the low cycle there will be a "back vacuum". If you are looking to use a liquid fuel such as in fuel rail, and there is no entrained air from a fuel source like propane, then the "back vacuum" is needed to fill in the missing entrained air.

I hope that makes sense.

Re: PyroJoes Recipe for Beginners

Posted: Wed Mar 07, 2012 7:37 pm
by metiz
Just made a sketchup model of both engines. This isn't some messed up perspective: the small engine's right on top of the big one!

Joe, I made some minor changes to the length of the intake elbows. They were so short that they merged with the choke cone. I think I added 10 or 15mm to the big engine, and <5mm to the small one.