Search found 19 matches

by lovot
Mon Dec 01, 2014 7:15 am
Forum: Valveless pulsejet forum
Topic: Wanted: plans for a 10-20Lb valveless PJ
Replies: 16
Views: 6449

Re: Wanted: plans for a 10-20Lb valveless PJ

Thanks Tufty, I never considered using the site limiter on Google. This is exactly what I needed. I think. Now that I have a design, I should be done fabricating the engine in a couple days. It has fewer welds than PyroJoe's recipe as an added bonus!
by lovot
Sun Nov 30, 2014 8:01 pm
Forum: Valveless pulsejet forum
Topic: Wanted: plans for a 10-20Lb valveless PJ
Replies: 16
Views: 6449

Re: Wanted: plans for a 10-20Lb valveless PJ

If you scale the escopette, it becomes something else, and any ideas of the original being easy to start, running consistently, producing x thrust, running at y Hz, etc, go straight out of the window. Frequency is determined by the length of the engine and the speed of sound at running temperature....
by lovot
Sun Nov 30, 2014 7:11 am
Forum: Valveless pulsejet forum
Topic: Wanted: plans for a 10-20Lb valveless PJ
Replies: 16
Views: 6449

Re: Wanted: plans for a 10-20Lb valveless PJ

scaling, especially downwards, is generally a bad idea. here's another set of escopette dimensions http://www.pulse-jets.com/phpbb3/download/file.php?id=45 I know scaling is a bad idea, but I don't have much choice. 4' is the upper limit for a test engine, otherwise the engine uses so much of my li...
by lovot
Sat Nov 29, 2014 12:48 am
Forum: Valveless pulsejet forum
Topic: Wanted: plans for a 10-20Lb valveless PJ
Replies: 16
Views: 6449

Re: Wanted: plans for a 10-20Lb valveless PJ

You want a straight valveless? Escopette / Escopeta http://www.pulse-jets.com/phpbb3/viewtopic.php?f=3&t=627 Thanks, I actually tried looking for some Escopette stuff, and couldn't find much about it except that it was a successful engine, not much information about thrust, efficiency or maximum op...
by lovot
Fri Nov 28, 2014 3:28 am
Forum: Valveless pulsejet forum
Topic: Wanted: plans for a 10-20Lb valveless PJ
Replies: 16
Views: 6449

Re: Wanted: plans for a 10-20Lb valveless PJ

You want a straight valveless? Escopette / Escopeta http://www.pulse-jets.com/phpbb3/viewtopic.php?f=3&t=627 Thanks, I actually tried looking for some Escopette stuff, and couldn't find much about it except that it was a successful engine, not much information about thrust, efficiency or maximum op...
by lovot
Wed Nov 26, 2014 11:58 pm
Forum: Valveless pulsejet forum
Topic: Wanted: plans for a 10-20Lb valveless PJ
Replies: 16
Views: 6449

Re: Wanted: plans for a 10-20Lb valveless PJ

I thought that there had to be someone here who knows how to make good valveless straight engines. Seems I was mistaken. I guess it's back to designing my own engines, which hasn't been successful in the past. I guess if I experiment enough I might make something functional.
by lovot
Tue Nov 25, 2014 11:55 pm
Forum: Valveless pulsejet forum
Topic: Wanted: plans for a 10-20Lb valveless PJ
Replies: 16
Views: 6449

Re: Wanted: plans for a 10-20Lb valveless PJ

Some of you might be wondering why I would want an engine that is one of the least efficient at producing static thrust Using your own words, apparently, thrust and efficiency don't matter, hence the suggestion. There is a difference between "I know the design limitations, and am prepared to accept...
by lovot
Mon Nov 24, 2014 11:30 pm
Forum: Valveless pulsejet forum
Topic: Wanted: plans for a 10-20Lb valveless PJ
Replies: 16
Views: 6449

Re: Wanted: plans for a 10-20Lb valveless PJ

You know you can just slap the intake of an existing engine on the front right? No, the reverse facing intake designs either don't even try to use aerodynamic valving* (like the lockwood), or have a design that pretty much demands that the intake is placed where it is (like the FWE). *Aerodynamic v...
by lovot
Sat Nov 22, 2014 7:35 pm
Forum: Valveless pulsejet forum
Topic: Wanted: plans for a 10-20Lb valveless PJ
Replies: 16
Views: 6449

Wanted: plans for a 10-20Lb valveless PJ

I am looking for plans for a valveless pulsejet capable of 10-20 pounds of thrust. I would have use some of the other plans available on this site, but it needs to have only one intake, which must be forwards facing, no bends, no thrust augmenter. Should be as compact as possible and built for speed...
by lovot
Sat Nov 22, 2014 7:04 pm
Forum: Valveless pulsejet forum
Topic: how to set up a liquid fuled engine
Replies: 16
Views: 7187

Re: how to set up a liquid fuled engine

What works best for me is a duel fuel system. Start the engine on propane, then turn on the liquid fuel. That's the plan, there was another method I could use to pressurize the liquid fuel tank without mixing the liquid fuel to the pressurizing gas that would be safer, but slightly more difficult a...
by lovot
Sun Oct 19, 2014 11:42 pm
Forum: Valveless pulsejet forum
Topic: how to set up a liquid fuled engine
Replies: 16
Views: 7187

Re: how to set up a liquid fuled engine

One possibility is a feeding of pressurized fuel towards a small inert gas cylinder as shown in the attachment. The nozzle must design it. http://webserver.dmt.upm.es/zope/DMT/Members/jmtizon/motores-cohete/bak/8_Almacenables.pdf Pressure harvesting was a bust, and my next plan is similar to the on...
by lovot
Sat Oct 18, 2014 5:28 pm
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1714376

Re: PyroJoes Recipe for Beginners

Yes, I have worked with shallow cones in many configurations. My work typically has revealed the need to maintain the Helmholtz properties of the CC as a chamber and the -inertial pumping- characteristics of a pipe for the tail. But I would recommend anyone to test it and come to their own reasonin...
by lovot
Sat Oct 18, 2014 5:16 pm
Forum: Valveless pulsejet forum
Topic: how to set up a liquid fuled engine
Replies: 16
Views: 7187

Re: how to set up a liquid fuled engine

OK, some tests have determined that vaporizing fuel is not a good idea, it seems to decompose by the time it's hot enough to vaporize, which would rapidly clog the fuel delivery system with carbon deposits, if I were using simple hydrocarbons or alcohol as fuel that wouldn't be a problem, but those ...
by lovot
Thu Oct 16, 2014 11:34 pm
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1714376

Re: PyroJoes Recipe for Beginners

@ PyroJoe: Thanks, have you done much experimentation with longer cones? I understand most people avoid them because they are more difficult to make than cylinders, especially long ones that have a very shallow slope (the one I was thinking of would have a slope of .05 or less). I noticed that the C...
by lovot
Tue Oct 14, 2014 11:05 pm
Forum: Valveless pulsejet forum
Topic: how to set up a liquid fuled engine
Replies: 16
Views: 7187

Re: how to set up a liquid fuled engine

I've only ever seen a gravity feed system on a valveless pulse-jet. It works but it's very crude. The problem is, a valveless pulse-jet is a finely tuned machine. Just taking some pressure from the combustion chamber is going to mess up the engine. If you want to harvest energy for your fuel delive...