Search found 4894 matches

by Mike Everman
Sun Jul 23, 2017 2:44 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

Yeah, that candle in a tube sets up what they call a thermal syphon used in some geothermal systems. The mind boggles at air going in one and out the other at the same time, which is certainly the case on the parent motor. Maybe its where this idea breaks down, as I just dont have enough volume to b...
by Mike Everman
Sun Jul 23, 2017 4:53 am
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

Yes, augmenters weight heavily in my plan. That should be interesting. Any way you slice it, noisier means more thrust. I just took a first step toward a closed end version of my pocket jet. Twin snorkels for you, Mark. ha It's tough (or maybe impossible) to make it acoustically identical to it's va...
by Mike Everman
Sat Jul 22, 2017 3:14 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

Cool, Mark, I'd love to do some experiments with with one of your snorkelers! I've got a new massive spreadsheet developing for pulsating combustor design. I've been getting cold and hot frequency measurements and matching them with theory. One of the interesting conclusions is, for my family of poc...
by Mike Everman
Sat Jul 22, 2017 12:02 am
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

The more I think on it, I think spinning the pot is bad. The incoming jet(we think) should be making a nice, doughnutty vortex in there. As soon as you try to spin the pot, I can imagine this inside out circular flow will precess and go chaotic and turbulent. Surely it's turbulent when it combusts, ...
by Mike Everman
Fri Jul 21, 2017 7:24 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

Ha, I'm 3d printing an hourglass shape right now for another project. I think a reynst pot might not need the venturi ring inside if it were wasp-waisted. I'm starting to lean toward not spinning the pot, but too early to tell...
by Mike Everman
Wed Jul 19, 2017 8:06 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

Yep, Well, two .36" holes runs for a few seconds but not super strong. wonder if I want a wall in there to keep the streams from hitting each other on the inside. I'm hit and miss on my benchmark 12 oz salsa bottle with .52" single hole running. humidity is all over the place, runs in the morning bu...
by Mike Everman
Sun Jul 16, 2017 5:39 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

Yeah, jostling is bad. I also need to protect my jets from the sideways slipstream, so i expect either some right angle snorkels or just a diverter sweep. The coors light aluminum bottle is pretty good, flattish bottom, short neck, screw cap. The shoulder is about 35deg from vertical. I wonder if i ...
by Mike Everman
Sun Jul 16, 2017 12:12 am
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

My thoughts too. Here's another try with rounder, but still tangential exits. I can get a brrrr, but thats all:
https://www.youtube.com/watch?v=WkxUnm0thwA&sns=em
Going to go look for likely candidates with more of a neck down. Perhaps they will be beerish.
by Mike Everman
Sat Jul 15, 2017 9:20 pm
Forum: Jet Vehicles, All Types
Topic: Jam Jar Car Fun
Replies: 22
Views: 3669

Re: Jam Jar Car Fun

A little better rig, trying for a torque motor:
https://www.youtube.com/watch?v=WkxUnm0thwA&sns=em
Fuel sloshes up,but is fortunately not on fire when it does the rainbird
by Mike Everman
Sat Jul 15, 2017 4:52 pm
Forum: Jet Vehicles, All Types
Topic: Jam Jar Car Fun
Replies: 22
Views: 3669

Re: Jam Jar Car Fun

I just posted a pajama science video of a soda can heli try on my build log.
by Mike Everman
Sat Jul 15, 2017 4:48 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

Been a long time since I've been here and obsessing about jam jars!
Trying to make a jam jar helicopter toy:

https://www.youtube.com/watch?v=mXgAOvkrOF4&sns=em
by Mike Everman
Sat Jul 15, 2017 4:48 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 364
Views: 77734

Re: Mike's Build Log

Been a long time since I've been here and obsessing about jam jars!
Trying to make a jam jar helicopter toy:

https://www.youtube.com/watch?v=mXgAOvkrOF4&sns=em
by Mike Everman
Sat Jul 15, 2017 2:35 pm
Forum: Jet Vehicles, All Types
Topic: Jam Jar Car Fun
Replies: 22
Views: 3669

Re: Jam Jar Car Fun

I'm thinking beer can with tangential jet exits or a diverter to make it spin, and fix some superlight rotors to that. Sit it on a bearing so it can get up some spin before lifting off. Theres the issue of being a burning fuel sprinkler, though.
by Mike Everman
Fri Jul 14, 2017 5:24 pm
Forum: Valveless pulsejet forum
Topic: Cant start pulse jet
Replies: 6
Views: 178

Re: Cant start pulse jet

Lengths and area ratios must be in a range, intake almost always needs a flared inlet. When using a leafblower, farther away from the intake is best. wave back and forth in various amounts of dead-on. It may be just the little fringe of the blower stream going in from a foot away. When you push it r...
by Mike Everman
Fri Jul 14, 2017 5:00 pm
Forum: Jet Vehicles, All Types
Topic: Jam Jar Car Fun
Replies: 22
Views: 3669

Re: Jam Jar Car Fun

Yeah, that is fun. And seriously, we need to do a jamjar helicopter. I may have to start a thread for that.