Search found 4923 matches

by Mike Everman
Mon Sep 17, 2018 10:57 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 375
Views: 98600

Re: Mike's Build Log

reduced impeller vid.mp4
(2.69 MiB) Downloaded 24 times
by Mike Everman
Mon Sep 17, 2018 10:47 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 375
Views: 98600

Re: Mike's Build Log

You know, once you let go of any dreams of high performance pushing a bike around with 5 lb of thrust, the problem opens up and gets really fun. Doing some math, I realized that making a larger diameter free turbine gets me very little. My original thought was that the thrust acting on a bigger radi...
by Mike Everman
Mon Sep 10, 2018 2:02 pm
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 37
Views: 4692

Re: Valveless pulsejet-computational fluid dynamics

Hi Ganesh, fuel is propane and i will post a pic of the fueling.
My motors are bent into a “u”. Do you need a straight or can you do the bent version?
by Mike Everman
Fri Sep 07, 2018 11:57 pm
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 37
Views: 4692

Re: Valveless pulsejet-computational fluid dynamics

Hi Zono and Ganesh, I'd like very much to know if this motor's intake and exhaust alternate. I'm about to put it to a turbine and in or out of phase is important. Any interest in running this geometry? I'm imagining test rigs to find out, but thought you guys would enjoy the idea. pocket jet, 3.5 lb...
by Mike Everman
Thu Sep 06, 2018 2:34 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 375
Views: 98600

Re: Mike's Build Log

Ah yessss, pushbutton starting works! 8AFD2B88-BCD7-4CE0-84AF-98E36625D9DB.jpeg I’ll get a youtube up of the successful result. I ran out of fittings, so decided to try a direct line to the starting stinger, and adjusting the needle valve going to the main feed. The next iteration needs ability to s...
by Mike Everman
Thu Sep 06, 2018 2:20 pm
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 14
Views: 277

Re: Subsonic Ramjet Design Project

Wouldn’t hurt to put an X rib on any big areas. You will wish you’d spent just a bit more on 304 or 321. I llok at some of my prototypes and wish I’d let go of mild steel much earlier. I’ve given the rectangular architecture a lot of thought and modeling, but no gas dynamic, stress or fatigue work, ...
by Mike Everman
Mon Aug 27, 2018 6:39 pm
Forum: Tools and Construction
Topic: Quartz
Replies: 42
Views: 14896

Re: Quartz

Drilling pinholes will be a hot topic if I have the glass blowers blow me a pocket jet. I would like to preserve the fueling I use, which will be tricky in quartz. Thinking laser.
by Mike Everman
Mon Aug 27, 2018 2:42 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 375
Views: 98600

Re: Mike's Build Log

Oh yeah, I suppose we did talk about this http://www.pulse-jets.com/phpbb3/viewtopic.php?f=3&t=4190&hilit=chicken+drive&start=15#p59619 I think I'm favoring the simple free turbine idea better now. I can imagine the Coriolis and centrifugal forces going on are going to massively hurt flow on the "sp...
by Mike Everman
Mon Aug 27, 2018 1:55 pm
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 14
Views: 277

Re: Subsonic Ramjet Design Project

IDK. I know it’s not a guessing or cut and try game though. There are governing gas dynamic principles you need to observe. Ones I do not know and have not researched.
by Mike Everman
Mon Aug 27, 2018 1:51 pm
Forum: Tools and Construction
Topic: Quartz
Replies: 42
Views: 14896

Re: Quartz

I’m going to make a plastic guide and see if I can cut it net size. The wire should make a nice finish if guided properly.
by Mike Everman
Sun Aug 26, 2018 8:32 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 375
Views: 98600

Re: Mike's Build Log

Hey Nick, hope all is well! Need to come out there in '19 for sure. I'd like to see this one too as it's been percolating for a long time, so am laying in some supplies. But anyone that reads this thread knows I'm all talk until I am not! I've had to scale back on work a bit for my sanity, so am ima...
by Mike Everman
Sun Aug 26, 2018 4:56 pm
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 375
Views: 98600

Re: Mike's Build Log

So I've got this notion to make a PJ powered bike out of a 1L pocket jet I have. Just go for a simple free turbine and gear it all down. I do not care about how fast I go, gearing it for 10-15ish MPH(?), assuming 100m/sec achievable tangential velocity(?) I do not have any interest in using a PJ big...
by Mike Everman
Sun Aug 26, 2018 4:37 pm
Forum: Tools and Construction
Topic: Quartz
Replies: 42
Views: 14896

Re: Quartz

I just ordered the diamond wire saw blade and holder as well. I also got a set of diamond files: https://www.amazon.com/gp/product/B00PAQWTI0/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1 My clockmaking buddy says he cuts tube by scoring it with a triangular diamond file and snapping it with his hands...
by Mike Everman
Fri Aug 24, 2018 11:47 pm
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 14
Views: 277

Re: Subsonic Ramjet Design Project

I don't know much about them, though I do know that getting a flow to stick to a wall that diverges more than 30 half angle would be a problem. Flat walls will need to be a honeycomb panel or otherwise greatly stiffened. You will be fighting drum head modes of vibration in flat walls.
by Mike Everman
Thu Aug 23, 2018 2:10 pm
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 14
Views: 277

Re: Subsonic Ramjet Design Project

Better. That last one I thought had too steep a diffuser.