Search found 1743 matches

by PyroJoe
Fri Jul 14, 2017 2:19 pm
Forum: Off topic forum
Topic: youtube
Replies: 1454
Views: 161929

Re: youtube

Good find, I may have to try one of those. :D
by PyroJoe
Fri Jul 14, 2017 2:17 pm
Forum: Jet Vehicles, All Types
Topic: Jam Jar Car Fun
Replies: 22
Views: 6119

Re: Jam Jar Car Fun

:wink:
by PyroJoe
Fri Jul 14, 2017 2:16 pm
Forum: Tools and Construction
Topic: TIG Welding
Replies: 1
Views: 522

Re: TIG Welding

Here is a calculator: https://www.millerwelds.com/resources/weld-setting-calculators/tig-welding-calculator If you put the type of metal and thickness in it should give a pretty close place to start. Anecdotally: You want to start with steel, (make sure to start with clean metal) make a puddle on th...
by PyroJoe
Fri Jul 14, 2017 2:02 pm
Forum: Valveless pulsejet forum
Topic: Cant start pulse jet
Replies: 6
Views: 1186

Re: Cant start pulse jet

Bangs are a good thing, and it can take over half a minute of fire to heat the tail up to running temperature. I don't think it's a matter of doing right or wrong. What we see is that there are sets of dimensions that lend themselves to resonant combustion. Size, shape and length of the resonant cha...
by PyroJoe
Thu Jul 13, 2017 9:24 pm
Forum: Jet Vehicles, All Types
Topic: Jam Jar Car Fun
Replies: 22
Views: 6119

Re: Jam Jar Car Fun

by PyroJoe
Thu Jul 13, 2017 9:18 pm
Forum: Valveless pulsejet forum
Topic: Cant start pulse jet
Replies: 6
Views: 1186

Re: Cant start pulse jet

Looks like the tail is a bit short. It might be helpful to look at the topic in the Valveless section called 'PyroJoes Recipe for Beginners'. I put that up to help show what dimensions are likely to work, and to help out folks new to the pulse jet experience.

As always, happy combustion!
by PyroJoe
Thu Jun 30, 2016 10:10 pm
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1698946

Re: PyroJoes Recipe for Beginners

Sorry for the late reply. It should look similar to this drawing. Thanks, and let us know how it goes
by PyroJoe
Thu Jun 30, 2016 9:35 pm
Forum: Valveless pulsejet forum
Topic: Lovely video...
Replies: 5
Views: 1215

Re: Lovely video...

Awesome camera work catching that. Thanks tufty.
by PyroJoe
Fri Oct 17, 2014 7:48 pm
Forum: Valveless pulsejet forum
Topic: how to set up a liquid fuled engine
Replies: 16
Views: 4584

Re: how to set up a liquid fuled engine

Probably the first thing to do is to understand that valveless pulse jets are not like regular mechanical piston engines. There is no mechanical piston to crush the fuel air together. There is no intake valve that shields the intake from the positive pressure from the combustion cycle. The factors I...
by PyroJoe
Fri Oct 17, 2014 4:42 pm
Forum: Tools and Construction
Topic: Odd Metal jars
Replies: 554
Views: 1730366

Re: Odd Metal jars

Example of an inertial pump
In this case the movement of the pump creates the change in velocity.
In valveless pulse jets I would offer that the process is driven by the pressure fluctuations created from combustion (along with the effects of aerodynamic valving).
by PyroJoe
Fri Oct 17, 2014 4:18 pm
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1698946

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 reasoning.
by PyroJoe
Thu Oct 16, 2014 1:11 pm
Forum: Off topic forum
Topic: youtube
Replies: 1454
Views: 161929

Re: youtube

Since I use a lot of galvanized pipe I see the yellow stuff often. sometimes it turns into a powder/dust like coating that can be wiped off. Sometimes it forms little dropplets of liquid metal that eventually evaporate. If the metal has been pickled in a certain way the underlying steel has a really...
by PyroJoe
Wed Oct 15, 2014 6:50 pm
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1698946

Re: PyroJoes Recipe for Beginners

Just to be clear, does tail expansion increase the efficiency of the engine? -From the concepts I have read, a tail expansion helps when the engine is run static. (sitting still) -When the engine is moving at a fast speed, the expansion is less needed. -It also helps the pressure in the combustion c...
by PyroJoe
Mon Oct 06, 2014 8:59 pm
Forum: Valved pulsejet forum
Topic: 20 lb Thrust Twin Engines
Replies: 2
Views: 1614

Re: 20 lb Thrust Twin Engines

That's awesome Rocket. How do you regulate between 2 psi and 10 psi fuel pressure?
by PyroJoe
Thu Oct 02, 2014 9:54 pm
Forum: Valveless pulsejet forum
Topic: how to set up a liquid fuled engine
Replies: 16
Views: 4584

Re: how to set up a liquid fuled engine

It takes considerable knowledge to switch from propane to petrol liquids in valveless pulse jets.