Search found 613 matches

by pezman
Fri Jan 14, 2005 11:04 pm
Forum: Valveless pulsejet forum
Topic: Alternate Fuels
Replies: 30
Views: 11446

Re: Alternate Fuels

Yeah, I was going to mention that efforts to obtain anhydrous ammonia is a good way to invite scrutiny. We're probably all under casual observation anyway. Whenever you try to explain the hobby, you can see people wondering if you're an evil mad scientist. On that topic, Bruce Simpson's $5k cruise m...
by pezman
Fri Jan 14, 2005 4:17 pm
Forum: Gas turbine forum
Topic: My turbine wheel
Replies: 59
Views: 33092

Re: My turbine wheel

Horace,

How much are you envisioning selling the turbine wheel for?

Do you have any ball-park figure for the cost of a fully assembled engine?

Awesome work!
by pezman
Fri Jan 14, 2005 4:20 am
Forum: Valveless pulsejet forum
Topic: Increasing Flame Acceleration
Replies: 24
Views: 7809

Re: Increasing Flame Acceleration

Blast Comprssion Valveless Pulsejet

Bruno Ogorelec wrote a nice review document about valveless pulse-jets that can be found here:
http://www.pulse-jets.com/valveless/index.htm

At the end, he proposes a blast compression idea that is pretty elegant.
by pezman
Fri Jan 14, 2005 1:03 am
Forum: Valved pulsejet forum
Topic: Need reed valve assembly for 100lb pulsejet
Replies: 7
Views: 4541

Re: Need reed valve assembly for 100lb pulsejet

Just remembered that SRL has film of an Argus clone that they built: http://www.srl.org/yard/ I think that they you can hear them saying on the film that they used more modern steel for the valves. Maybe they there's a chance of help from them to get jump-started? A lot of intricate fabrication in t...
by pezman
Thu Jan 13, 2005 10:02 pm
Forum: Valveless pulsejet forum
Topic: Proposed CC design
Replies: 48
Views: 18708

Re: Proposed CC design

A prolate ellipsoid (or prolate spheroid) is a stretched spheroid -- a.k.a an egg.

An oblate spheroid is what your basket ball becomes if you sit on it.
by pezman
Thu Jan 13, 2005 9:56 pm
Forum: Valved pulsejet forum
Topic: Need reed valve assembly for 100lb pulsejet
Replies: 7
Views: 4541

Re: Need reed valve assembly for 100lb pulsejet

I think its a derivative of the Argus (plans here: http://www.pulse-jets.com/count/pulse.php?ID=28)
by pezman
Thu Jan 13, 2005 1:59 pm
Forum: Valveless pulsejet forum
Topic: Proposed CC design
Replies: 48
Views: 18708

Re: Proposed CC design

I hope this helps you to understand better.
Yeah, Larry, have you been enlightened yet ;)?
by pezman
Thu Jan 13, 2005 12:47 am
Forum: Pulse detonation engine forum
Topic: Nice tutorial on detonation
Replies: 1
Views: 5106

Nice tutorial on detonation

A nice starting point on the topic.

http://www.gexcon.com/index.php?src=han ... Bchap6.htm
by pezman
Wed Jan 12, 2005 10:43 pm
Forum: Valveless pulsejet forum
Topic: Proposed CC design
Replies: 48
Views: 18708

Re: Proposed CC design

Well, I think that the shock waves have a relatively short wavelength that are more or less like a thin shell expanding spherically. http://www.pulse-jets.com/phpbb2/files/shock_wave_leaving_tube_svort1_140.gif It should be possible to focus and aim these and make use of them -- BUT, the propogating...
by pezman
Wed Jan 12, 2005 6:03 pm
Forum: Valveless pulsejet forum
Topic: Proposed CC design
Replies: 48
Views: 18708

Re: Proposed CC design

Wouldn't your requirements describe a CC that is shaped like an egg?

Probably not a bad idea, btw.

edit: Just read more carefully -- not an egg. Has anyone experiment w/ "eggs"?
by pezman
Wed Jan 12, 2005 5:51 pm
Forum: Valveless pulsejet forum
Topic: proposed engine design
Replies: 6
Views: 3223

Re: proposed engine design

Cool idea! I think I may play with something like this. Here is a similar idea that I found a while back: http://conceptengine.tripod.com/conceptengine/id2.html It seems like a close cousin to your fly-wheel idea, although the engine in the above link converts thrust into rotary motion to drive the ...
by pezman
Wed Jan 12, 2005 4:25 pm
Forum: Valveless pulsejet forum
Topic: proposed engine design
Replies: 6
Views: 3223

Re: proposed engine design

Boom likelihood depends on the fuel. Some fuels have relatively wide limits of flammability (H2, Acetylene, Methanol etc.), others have fairly narrow limits (Propane, Gasoline (I think), etc.). That aside, a free-piston design that pumps the pulse-jet would be pretty cool. The resonant frequency of ...
by pezman
Tue Jan 11, 2005 8:24 pm
Forum: Valveless pulsejet forum
Topic: Increasing Flame Acceleration
Replies: 24
Views: 7809

Re: Increasing Flame Acceleration

There is nothing to inherently prevent combustion from occurring all the way down the tube. In fact, according to Tharratt, that's exactly what happens. Put enough fuel in the pipe, and it is guaranteed that a good bit of it will arrive at the end uncombusted. In addition, under the right conditions...
by pezman
Tue Jan 11, 2005 8:11 pm
Forum: Valved pulsejet forum
Topic: A possible fractal in a pulse combustor ...
Replies: 22
Views: 6951

Re: A possible fractal in a pulse combustor ...

Nice puzzle. I figured it depended on the angle, so the result made sense after I saw it. On the other hand, I can;t make any claim that I wold have come up w/ an analytical result. I guess that the pencil is "almost certain" to touch the line when it is rotated +/- pi/2, and almost certain to miss ...
by pezman
Tue Jan 11, 2005 6:03 pm
Forum: Valveless pulsejet forum
Topic: Proposed experiments for FWE
Replies: 22
Views: 6436

Re: Proposed experiments for FWE

Hmm, I have something a little like this lurking down in my basement. As far as getting analytical information for designs, I think that modeling is hopeless, since the heat gradients in the engine cause the speed of sound to vary over time and distance. I'm pretty sure that you'd need a big-ticket ...