Search found 571 matches

by Graham C. Williams
Wed Dec 10, 2008 7:47 pm
Forum: Valved pulsejet forum
Topic: dynamic modeling of a strip valve
Replies: 144
Views: 2875623

Re: dynamic modeling of a strip valve

Great bit of work Grim and Forrest.
Is a W shaped valve block in the offing?

Graham.
by Graham C. Williams
Mon Dec 08, 2008 8:19 pm
Forum: How to improve this site
Topic: Rossco injector
Replies: 1
Views: 2527

Rossco injector

Questions about the Rossco injector appear regularly. Perhaps collect all the stuff and make it a sticky under Tools?

Graham.
by Graham C. Williams
Mon Dec 08, 2008 7:49 pm
Forum: Valved pulsejet forum
Topic: dynamic modeling of a strip valve
Replies: 144
Views: 2875623

Re: dynamic modeling of a strip valve

Hi Forrest.
That impresses the hell out of me. Only one odd harmonic and DC, Hmm.
Is the function reasonably easy to use?

Graham.
by Graham C. Williams
Mon Dec 08, 2008 2:10 pm
Forum: Valveless pulsejet forum
Topic: New guy getting started
Replies: 53
Views: 11440

Re: New guy getting started

by Graham C. Williams
Sun Dec 07, 2008 9:14 pm
Forum: Valveless pulsejet forum
Topic: New guy getting started
Replies: 53
Views: 11440

Re: New guy getting started

Hi Clay.
You could try this method:

viewtopic.php?f=3&t=2021&start=0&st=0&sk=t&sd=a

Graham.
by Graham C. Williams
Sat Dec 06, 2008 5:16 pm
Forum: Valved pulsejet forum
Topic: dynamic modeling of a strip valve
Replies: 144
Views: 2875623

Re: dynamic modeling of a strip valve Jerk

Agreed.
And finally do you think that the 3rd derivative (Jerk?) in the region near where the valve opens and closes would materially influence the valve life?
by Graham C. Williams
Sat Dec 06, 2008 2:01 am
Forum: Valved pulsejet forum
Topic: dynamic modeling of a strip valve
Replies: 144
Views: 2875623

Re: dynamic modeling of a strip valve

Wow, That's a good fit. The second derivative looks very good. I've been wondering if an FFT Analysis of the curves could generate a better fit? Perhaps by creating the curves as abstract amplitude values against dimensionless time then expressing the result of the analysis as a polynomial? Hmm, now...
by Graham C. Williams
Fri Dec 05, 2008 11:55 am
Forum: Valveless pulsejet forum
Topic: See through jet
Replies: 53
Views: 11540

Re: See through jet

Casio ExLim. High speed movie recording at up to 1200 fps

http://exilim.casio.com/browse_cameras/ ... lim/EX-F1/

Graham
by Graham C. Williams
Fri Dec 05, 2008 8:37 am
Forum: Valveless pulsejet forum
Topic: New guy getting started
Replies: 53
Views: 11440

Re: New guy getting started

... Or could one simply scale up the Short Lady design? I didn't think you could really simply scale up a design, since resonance plays a role and I can't imagine that ratio to size is simply linear. I have been searching here for about 20 minutes with no large lockwood plan results. Any ideas? Tha...
by Graham C. Williams
Wed Nov 26, 2008 7:44 pm
Forum: Valveless pulsejet forum
Topic: See through jet
Replies: 53
Views: 11540

Re: See through jet

Hi Metiz You could try Silicone sealant. Nothing special, the clear stuff you'd use round a bath. In my experience it's tough stuff and will last longer than the glass. If you use it as a bed as opposed to a thin adhesive layer the little bit of additional flexibility may help cushion the glass from...
by Graham C. Williams
Fri Nov 07, 2008 1:13 am
Forum: Valved pulsejet forum
Topic: dynamic modeling of a strip valve
Replies: 144
Views: 2875623

Re: dynamic modeling of a strip valve

Dear Forrest. I'm sorry for this stupid question but this work is important (at least to me)! Using Your Graph for w/wn=0.3 as an example and telling you that the colours for p12 and Theta are similar on my monitor. Is the Lower of the two lines the Reed action and the upper the Pressure drop or is ...
by Graham C. Williams
Fri Nov 07, 2008 12:19 am
Forum: Valved pulsejet forum
Topic: dynamic modeling of a strip valve
Replies: 144
Views: 2875623

Re: dynamic modeling of a strip valve

Dear Forrest.
Wonderful stuff.
Is it possible to see the response of the valve (&p12) when the exciting pressure in the box (Psource)is offset in the +ve direction, say about 0.5psi?

Graham.
by Graham C. Williams
Thu Nov 06, 2008 4:38 pm
Forum: Valved pulsejet forum
Topic: The Cybernetics of a Pulse Combustor
Replies: 28
Views: 2819614

Re: The Cybernetics of a Pulse Combustor

Dear Forrest. I'm wondering if the Damping Curve is itself a function of a number of variables that can change during the motors start-up process. It wouldn't surprise me at all. Lately I've been modelling (with NUDiS) some short valveless motors. 'Short' as in The total combustion time being a long...
by Graham C. Williams
Wed Nov 05, 2008 8:52 pm
Forum: Off topic forum
Topic: Death of jetZILLA Predicted
Replies: 25
Views: 13746

Re: Death of jetZILLA Predicted

And what a shame that the company responsible for some of the Great "Akira Kurosawa" films should also be responsible for this?

Graham.
by Graham C. Williams
Wed Nov 05, 2008 8:15 pm
Forum: Off topic forum
Topic: Death of jetZILLA Predicted
Replies: 25
Views: 13746

Re: Death of jetZILLA Predicted

Dear Larry.
Thank you so much for this.
I now see Godzilla in a totally new way!
You are a real JOY

Best Regards
Graham.