Search found 1743 matches

by PyroJoe
Thu Oct 02, 2014 8:32 pm
Forum: Valveless pulsejet forum
Topic: Testing the sound output of a Small Pulsejet
Replies: 8
Views: 3550

Re: Testing the sound output of a Small Pulsejet

There is alot of throttle from the 110dB up to about 120dB then you can start hearing the tail being driven above 120. I find it better to decrease the CC length so that it drives the tail sooner. It typically will lock in faster and can be pushed harder.
by PyroJoe
Thu Oct 02, 2014 7:03 pm
Forum: Valveless pulsejet forum
Topic: Testing the sound output of a Small Pulsejet
Replies: 8
Views: 3550

Re: Testing the sound output of a Small Pulsejet

That's a pretty good first motor, the combustion chamber sounds a little long (13mm maybe?).
The CC is supposed to glow, as well as half the tailpipe nearest to the chamber.
by PyroJoe
Thu Oct 02, 2014 6:11 pm
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1710339

Re: PyroJoes Recipe for Beginners

Good to hear you got it humming along. That dB meter was extra icing on the cake!
by PyroJoe
Fri Sep 12, 2014 8:44 pm
Forum: Valveless pulsejet forum
Topic: M500 build log
Replies: 161
Views: 51177

Re: M500 build log

Good to hear you are recovered, I was concerned for weeks.

Those are some big tears in the tailcone. If windings prevent that, we should use them more often!
by PyroJoe
Fri Sep 12, 2014 5:58 pm
Forum: Valveless pulsejet forum
Topic: M500 build log
Replies: 161
Views: 51177

Re: M500 build log

Ha my mistake, yours was one of a few that has been built with the tail cone winding of that size. Must be a long lost brother of ours. :lol:

Hope your burns are mending well.
by PyroJoe
Thu Sep 11, 2014 10:01 pm
Forum: Valveless pulsejet forum
Topic: M500 build log
Replies: 161
Views: 51177

Re: M500 build log

Holy gods of thunder, wow, wow, wow!
by PyroJoe
Thu Sep 11, 2014 9:58 pm
Forum: Valveless pulsejet forum
Topic: M500 build log
Replies: 161
Views: 51177

Re: M500 build log

:shock: :shock: :shock: :shock:

https://www.youtube.com/watch?v=1R406q76sEA

How did you ever keep that back tire from melting?

Outstanding!
by PyroJoe
Tue Jul 29, 2014 9:44 pm
Forum: Valveless pulsejet forum
Topic: M500 build log
Replies: 161
Views: 51177

Re: M500 build log

Hope your doing well. Aloe vera works good if you can find it. Had trouble with my injectors moving also.
These big ones take some getting used to.
by PyroJoe
Mon Jul 21, 2014 5:14 pm
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1710339

Re: PyroJoes Recipe for Beginners

Read that link three times over the last few weeks. One of the few weak spots is the chamber volume, and the angle into the tailpipe are not well defined. Aerodynamic valving was not well considered. Trying to discover the best TSFC without adequate throttle range would be difficult IMO. There was m...
by PyroJoe
Mon Jun 02, 2014 1:23 pm
Forum: Valveless pulsejet forum
Topic: M500 build log
Replies: 161
Views: 51177

Re: M500 build log

Amazon has a hunting scale not sure were you could find one locally, maybe a restaurant supply store:

http://www.amazon.com/Buffalo-Outdoor-H ... B00C1WRFHG
by PyroJoe
Fri May 30, 2014 8:34 pm
Forum: Valveless pulsejet forum
Topic: M500 build log
Replies: 161
Views: 51177

Re: M500 build log

Svarthalet Racing found one that didn't break. The local Seismographs should be able to tell you the frequency. :wink: It's been good watching this come together. be safe, and use chain.
by PyroJoe
Mon Dec 09, 2013 6:48 pm
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1710339

Re: PyroJoes Recipe for Beginners

Good job, Looks like the combustion chamber could be a couple of centimeters shorter, but it starts easy enough. The problem I encountered with air bleed systems is there is on average about 1 to 2 psi of pressure near the CC. If the system is moved far away from the CC then the intake typically wil...
by PyroJoe
Thu Dec 05, 2013 12:35 am
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1710339

Re: PyroJoes Recipe for Beginners

I think that internal ball shaped cone may be giving some problems. Any idea how long it was? A well shaped cone can make a significant difference.
viewtopic.php?f=7&t=5901

I see good results with the 20 degree cones. :wink:
by PyroJoe
Wed Dec 04, 2013 3:04 pm
Forum: Valveless pulsejet forum
Topic: PyroJoes Recipe for Beginners
Replies: 209
Views: 1710339

Re: PyroJoes Recipe for Beginners

That cone section appears to have about 235,433 cubic mm. For a 2"dia. intake I included a drawing for the internal dimensions. Caliber appears to be 2.27". My apologies I didn't check in sooner. Good to see you fellas working it out.
by PyroJoe
Sun Oct 13, 2013 2:11 pm
Forum: Unconventional, Multi-Mode and Hybrid Jets
Topic: Cyclonic Vacuum Jet
Replies: 5
Views: 3189

Re: Cyclonic Vacuum Jet

I have wondered in the past if that would help. I had dismissed it at the time because my thinking was that the pressure created would push through the cyclone action and just blow out the intake in a linear way, taking the path of least resistance and destroying/collapsing the cyclone effect. If I ...