Search found 83 matches

by Stuart
Mon Sep 06, 2004 3:31 pm
Forum: Valveless pulsejet forum
Topic: I need some guidance for a simple project.
Replies: 14
Views: 5459

Re: I need some guidance for a simple project.

I just use mild steel exhaust pipe that you can get at auto parts shops or muffler shops. Here in the US you can get up to 2.5 inch pretty easily, 3" gets harder. Remember, this is just a prototype you are building, so cheaper is better, cause you are going to be building a bunch of variations guara...
by Stuart
Sun Sep 05, 2004 4:03 pm
Forum: Pressure jet forum
Topic: Is it a steady burner or a pulse jet?
Replies: 4
Views: 5085

Re: Is it a steady burner or a pulse jet?

Interesting Viv. I am building my own variation of a pressure jet. My design is pretty different than a Glueharath. I don't have it proportioned correctly yet (modify, learn, modify, learn), so it isn't putting out a lot of thrust, but it does work. I'll start listening for evidence of pulsation now...
by Stuart
Fri Aug 27, 2004 11:30 am
Forum: Valveless pulsejet forum
Topic: Nanosoft's annular jet
Replies: 42
Views: 18083

Re: Nanosoft's annular jet

Just to add some edumacation, boundary layer effects are not strongly affected by surface roughness, so smoothing the walls in an annular will not completely compensate for the added surface area. - I used the word friction before but it is really the viscous action in the fluid that causes a veloci...
by Stuart
Fri Aug 27, 2004 1:42 am
Forum: Valveless pulsejet forum
Topic: Nanosoft's annular jet
Replies: 42
Views: 18083

Re: Nanosoft's annular jet

For annular designs, remember there is a lot more friction from "boundary layer" effects. That is, viscous frictions along the walls and annular designs have much more such boundary area. So, I suspect you will have to enlarge the thinnest passageways. Of course, with these engines it could always b...
by Stuart
Fri Aug 27, 2004 1:36 am
Forum: Valveless pulsejet forum
Topic: Im gonna have some fun this weekend :D
Replies: 11
Views: 5022

Re: Im gonna have some fun this weekend :D

Just remember what your mum says: "It's always fun until you poke someone's eye out!"
by Stuart
Sun Aug 22, 2004 11:45 pm
Forum: Valveless pulsejet forum
Topic: Nanosoft, Asked Again
Replies: 65
Views: 30833

Re: Nanosoft, Asked Again

It cleared up enough to go out and test the engine again. I toke 1 inch off the intak and replaced it with a intake flare. I was hoping for a improvement but got disaster. It won't sustain! The combustion hot spot has moved all the way down the exhaust pipe(see picture). It will only run with compr...
by Stuart
Thu Aug 19, 2004 2:53 pm
Forum: Off topic forum
Topic: Ducts and power
Replies: 6
Views: 1825

Re: Ducts and power

Viv says "What about friction?" So right you are. I had some fluid dynamics classes that touched on this, but I've forgotten the details. Friction, causes heat, which I believe actually can speed up the velocity. It's one of those complex entropy AND energy problems, so the results aren't necessaril...
by Stuart
Thu Aug 19, 2004 1:00 am
Forum: Off topic forum
Topic: Ducts and power
Replies: 6
Views: 1825

Re: Ducts and power

I actually have some practical uses for this kind of thing, thanks for posting this. loooonggg ducts will have strange velocity characteristics.
by Stuart
Wed Aug 11, 2004 5:53 pm
Forum: Valveless pulsejet forum
Topic: Proposed Design: Elektra II - Revised Version
Replies: 14
Views: 18978

I don't usually follow the acoustic arguments much, but I am curious if anyone "beats their pipes" - I know that may have a couple meanings. But, tapping the engine and finding out the frequency (when it isn't running) should be related to the operating frequency in some way.
by Stuart
Tue Aug 10, 2004 5:26 am
Forum: Valveless pulsejet forum
Topic: Proposed Design: Elektra II - Revised Version
Replies: 14
Views: 18978

I think I'm going to start wrapping my fuel line around the tail pipe for a little heat recovery. Doesn't make sense if you are trying to evolve to liquid fuel, but would give you a little extra Gluey poop from propane. Also, if you are using propane, nozzling your copper fuel line tip (with a pinch...
by Stuart
Tue Aug 10, 2004 5:16 am
Forum: Valveless pulsejet forum
Topic: What Makes the Great Engines Great?
Replies: 16
Views: 6338

Well done Larry, 1) I think the intake lip is very important. A conical intake may also make a difference, but the lip is different than a conical section, even if they result in the same intake frontal area 2) Efficiency depends on mass flow because energy goes up by mv^2 while thrust goes up by mv...
by Stuart
Mon Aug 09, 2004 4:24 am
Forum: Valveless pulsejet forum
Topic: How Loud?
Replies: 8
Views: 3644

"In this photo, a fire broke out after running for several minutes." Bwahaha! I wish the old forum was up, someone described cleaning a chicken house and having it explode as one of their first adventures. Yes, the standard warnings are in order for newbies: Fires, high noise levels, fireballs, blow...
by Stuart
Sun Aug 08, 2004 4:19 pm
Forum: Valveless pulsejet forum
Topic: BCDSVP idea...
Replies: 13
Views: 7361

it would work

Great idea, it would work. The -out of phase- will likely set up on it's own.
by Stuart
Sat Aug 07, 2004 2:04 am
Forum: Valveless pulsejet forum
Topic: Lockwood Hiller engine
Replies: 20
Views: 8257

{ with peak pressures of 220 Kpa available it should be possible to pressurize a liquid fuel system adequately without the need for external pumps, electrics, etc. The reduction in thrust would seem negligible to add this function. Bill H. Acoustic Propulsion Concepts} a pitot in the exhaust train w...
by Stuart
Wed Aug 04, 2004 8:36 pm
Forum: Valveless pulsejet forum
Topic: Phoenix Song.
Replies: 47
Views: 18167

Bruno, I think your original BCVP has a chance to work, from the line of things I'm doing I can say that "it's all in the loop". But, the devil is always in the details.

The Albion design, all I can say is, WTF?