pulsejet virus

[Steve Wallington]

Hi all
I think i must have a bad case of this virus. I saw this piece of 1 3/4" pipe on ebay and had to buy it. I could see 2 jets in it. I had told my wife , and myself, no more builds untill i had learnt a bit more how they work. I had almost finished the small pair when Bruno goes and puts on more stuff to think about. I even wake up in the night thinking about liquid fuel systems, whats that all about.
I nearly got both jets running together but one flamed out and almost got the cameraman (wife). She wouldnt play after that, we had to go to the pub. I think i might have caught sound poisoning because my head hurt after.
Cheers Steve

[Hank]

Steve- You make no mention of stopping along the road to pick up an item your brain translates as having Pulse Jet Potential, or climbing into bins to retrieve same. Sounds like a mild case.

TM-1131 is available from the NACA Technical Report Server. It can be printed out for constant, pedantic perusal.

[Bruno Ogorelec]

Steve, you should tell your wife that flameouts are really a neat way to remove body hair without the trouble of shaving or depilation or any of that stuff. Ask Mike Everman. He has lost body hair to flameouts at the damnedest of places.

Your pair of Lockwoods looks very neat. I am glad you are getting ideas from me and sorry they are causing trouble. There's no vaccine for the pulsejet virus yet. But, as Hank says, you've still got it in a mild form.

I am in a phase in which I am throwing old stuff out -- cleaning the cupboard, as it were, and all those concepts are coming out in a stream. If and when I find time, I'll publish more. I have reams of such stuff on my files. Some of it a bit weird.

Have fun!

[Mike Everman]

Steve,
Yeah, you've got it bad. I'm still nursing my pulsejet head. I think it's been actively kicking my butt since my first post in Nov of '03. Bruno and Viv nursed me along initially, but really have made it worse over the years. l-)

Everything I look at either has or has no potential for jet building. That's the two states of matter these days.

My time spent pulsejetting has been golden! Your wife is a peach, mine doesn't want to be anywhere near it all.

[Johansson]

Nice!

A quick question, did you run the engines without ear protection? It looks like that from the video clip, but I have a hard time to believe that anyone would do that to themself.

(But then, I am a high-end audio geek that thinks a vaccum cleaner makes to much noice to be used without hearing protection. Quite funny that I would get hooked to the jet engine hobby concidering that... *LOL*)

//Anders

[Nick]

Hi Steve,


At last a fellow nutter in the locale!!!!! about time too!

( wonders if virus is spread by proximity?)

(Graham is mad of course, but lives a fair distance away, curiously wont listen to reason and move closer)

I Live just outside Bristol but work there, fancy a meet?


Lovely pair of lockwoods mate, nice welding!.

Nick

[Knight]

Steve- You make no mention of stopping along the road to pick up an item your brain translates as having Pulse Jet Potential, or climbing into bins to retrieve same.

GUILTY!

[Bo Danerius]

Your pair of Lockwoods looks very neat. I am glad you are getting ideas from me and sorry they are causing trouble. There's no vaccine for the pulsejet virus yet. But, as Hank says, you've still got it in a mild form.

I am in a phase in which I am throwing old stuff out -- cleaning the cupboard, as it were, and all those concepts are coming out in a stream. If and when I find time, I'll publish more. I have reams of such stuff on my files. Some of it a bit weird.

Have fun!

What would happen if the two jets were connected together with a u-tube? As in this drawing:

/Bo

[Nick]

Over to you Bruno :D

Well i dont think Steve has tried this but other people have and basically they stop :(

but thats what the Phoenix project/BCVP is all about :wink:

Nick

[hinote]

Well i dont think Steve has tried this but other people have and basically they stop :(

I'm predicting Eric will have something to say about all this.

[Mike Everman]

Just some observations:
So the units alternate, there is little time for one to pull fresh air in the gap before the blast comes through the u-tube, but maybe. That aside, the ducts need to be designed to handle ram air. Consider that the operation requires the incoming air to come to a near stand-still in the cc before or during combustion.
If you are going to ram a plug of fresh air in with a plug of hot exhaust, then the intake needs to slow the gas down again, either by being longer, or conical for diffusion or some other way.

And, I've been all wet before!

Maybe it'll work, you're well disposed to try it out. Let us know!

[Bo Danerius]

Over to you Bruno :D

Well i dont think Steve has tried this but other people have and basically they stop :(

but thats what the Phoenix project/BCVP is all about :wink:

Nick

Well. The idea came after reading Brunos pdf on BCVP :) I´ve done some searching on the subject here but missed out on the magic word "phoenix" wich generated a lot more hits. The idea has been mentioned at least once before this one :D

/Bo

[pezman]

If you bend them such that the tail of the one feeds the input of the other and vice-versa, the timing works out about right.

[Anders Troberg]

What would happen if the two jets were connected together with a u-tube? As in this drawing:

I had a very similar idea, although with two Escopettes, which I called the "Double barrel escopette". Never had the opportunity to try it.

Well i dont think Steve has tried this but other people have and basically they stop

I think that it needs careful tuning, as the jet is now recieving "timing information" from both ends.

I even considered cutting the tail and just put an augmentor instead. That would make both ends act more like an intake, and ignition would be provided only by the hot charge coming through the U-bend. With some luck, that hot charge will such some fresh air behind it, which will then be forced into the CC ahead of the hot exhaust on the next cycle. If it could be made to run, it would breathe exceptionally good, which could allow a higher frequency of operation, which could be adjusted by the length of the U-bend.

It probably takes a heap of work to tune it, although the construction makes it fairly simple to do.

[Bruno Ogorelec]

Bo,

J.A.C. Kentfield patented 'your' layout (US PAT 4033120) in 1977. His idea is a bit more complex, as it also couples the tailpipes, but the connector between the intake is near-identical.

For the people who have not heard of Kentfield, he is arguably the greatest living authority on pulsejets.

Mike,

You don't have to slow down or diffuse your blast for compression purposes. You just have to feed it from both sides at once.