Search found 4894 matches

by Mike Everman
Sat Jun 24, 2017 4:35 pm
Forum: Tools and Construction
Topic: Odds and ends
Replies: 1708
Views: 248518

Re: Odds and ends

I was thinking drops falling down a flue long enough that they go spherical, but then somehow want to not distort when cold is instantly, somehow, applied. Liquid nitrogen vapor lower in the flue, but with baffles or something to make a sharp change in temperature, I'm thinking. We want the highest ...
by Mike Everman
Sat Jun 24, 2017 3:04 am
Forum: Tools and Construction
Topic: Odds and ends
Replies: 1708
Views: 248518

Re: Odds and ends

Which reminds me that I want to try and make some perfectly spherical Prince Rupert's drops.
by Mike Everman
Thu Jun 22, 2017 1:43 pm
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 345
Views: 1723886

Re: Please put your "I am new and need help" question here.

Welcome! Start a build log thread for this titanium jet. Should be good. Can't wait to see the color of it running. I have a similar Thermojet, but a bit smaller. Looks like you areabout ready to weld.
by Mike Everman
Wed Jun 21, 2017 1:35 am
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 32
Views: 1062

Re: Valveless pulsejet-computational fluid dynamics

Ha, nice. Sure does seem that the intake and exhaust alternate. I truly think that u-bent motors benefit from this effect.
by Mike Everman
Thu May 11, 2017 2:47 pm
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 32
Views: 1062

Re: Valveless pulsejet-computational fluid dynamics

Ha! Nice. Oh yeah, I need to dig up jet dimensions for you!
by Mike Everman
Fri Apr 28, 2017 5:46 pm
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 32
Views: 1062

Re: Valveless pulsejet-computational fluid dynamics

The velocity has a direction vector left and right. Maybe a silly thing I'm wondering, as we see the propagation of the velocity changes, which does indicate a change in direction. I'm trying to wrap my mind around whether I can be fooled by interpreting the propagation of the velocity change with g...
by Mike Everman
Fri Apr 28, 2017 5:23 pm
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 32
Views: 1062

Re: Valveless pulsejet-computational fluid dynamics

Oh, that one is fun to watch! I would love to see the pressure animation as well. Does it not make sense that the velocity scale should be -300 to +300m/sec? Loses that "hot-cold" spectrum, but freezing it would allow some better interpretation.
by Mike Everman
Wed Apr 26, 2017 2:39 pm
Forum: Gas turbine forum
Topic: 3D-printed jet engine, sort of...
Replies: 5
Views: 823

Re: 3D-printed jet engine, sort of...

True that. Nice work!
by Mike Everman
Sun Apr 23, 2017 1:05 am
Forum: Valved pulsejet forum
Topic: German ER90 testing
Replies: 15
Views: 2619

Re: German ER90 testing

Just got around to watching these tests. Nice rig, and great work!
by Mike Everman
Thu Apr 20, 2017 2:34 pm
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 32
Views: 1062

Re: Valveless pulsejet-computational fluid dynamics

That one sure looks like the exhaust and intake are in synch after it settles in. Maybe a little bit off. I didn't realize you could fold the geometry. That's cool. Ive always thought that a u-shape motor would be more energetic if the exits were alternating, where one make a higher pressure ambient...
by Mike Everman
Wed Apr 19, 2017 3:13 pm
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 32
Views: 1062

Re: Valveless pulsejet-computational fluid dynamics

Great, I'll dig it up today. What is your time zone?
by Mike Everman
Wed Apr 19, 2017 1:46 pm
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 32
Views: 1062

Re: Valveless pulsejet-computational fluid dynamics

Hi Ganesh, sounds like a pulsejet! A mic at the intake and exhaust would be interesting to see compared. I am particularly interested in the phase offset, is it 180 or 90? My knee-jerk is 180, but... It will tell us something about the average speed of sound in the duct. I would like to set up a mot...
by Mike Everman
Sun Mar 26, 2017 5:09 am
Forum: Valved pulsejet forum
Topic: Can pulse jets perform better using Diesel fuel
Replies: 1
Views: 264

Re: Can pulse jets perform better using Diesel fuel

There is nothing wrong with it as a fuel. My knee-jerk opinion is that it would be better off in larger motors, and that because the flame speed is low. I'm searching for a table, but generally I would compare autoignition temperatures, flame speeds, stoichiometric mix. Yes, it does have a high ener...
by Mike Everman
Tue Mar 21, 2017 7:29 am
Forum: Valveless pulsejet forum
Topic: Valveless pulsejet-computational fluid dynamics
Replies: 32
Views: 1062

Re: Valveless pulsejet-computational fluid dynamics

Hey Ganesh, I too have not been around much, but think i should. Hope all is well with you too. Looks like fun. You might try low pressure ambient at the tail if your start condition is high at the intake. All these years, and the one thing i still want to show on a running motor is the alternating ...