Search found 80 matches

by cudabean
Wed Jan 28, 2004 8:37 pm
Forum: Valved pulsejet forum
Topic: Split pulsejet chambers
Replies: 2
Views: 3327

I've thought of similar ideas. One idea that springs to mind after seeing your design is rather than having a flexing membrane, have a sliding part, but then you have a moving part and all of its associated problems. Another thing I thought of about ten years ago is to control the firing of the sepa...
by cudabean
Tue Jan 27, 2004 11:01 pm
Forum: Off topic forum
Topic: Europeanese
Replies: 13
Views: 7515

The thing that throws me for a loop as an American who frequently listens to the "BEEB" (BBC world service). Is when large mumbers are discussed. For example: US 1x10^6 = Million 1x10^9 = Billion 1x10^12 = Trillion UK 1x10^6 = Million 1x10^9 = Thousand million 1x10^12 = Billion? 1x10^15 = Trillion? ...
by cudabean
Wed Jan 21, 2004 2:13 am
Forum: Off topic forum
Topic: Supersonic wing simulator
Replies: 2
Views: 2228

That's neat. I think the funnest part of that is draging the shape of the wing and watching the shock/expansion waves and lift/drag vector flit around while you rearange the shape. Cool!

cudabean
by cudabean
Wed Jan 21, 2004 1:57 am
Forum: Gas turbine forum
Topic: Turbojet combustor cans
Replies: 5
Views: 4832

Yep! got that book, and a very good book it is too, thanks for the links Bruno I will check them out. Hmm.. I ordered that book from Amazon too! I like it except for the way that pulsejets are summarized in a paragraph or two, IIRC. http://www.iop.org/EJ/abstract/1468-5248/3/1/030 http://www.turbul...
by cudabean
Sat Jan 10, 2004 2:26 am
Forum: Valveless pulsejet forum
Topic: 75mm Locky Kazoo (say that 10 times fast)
Replies: 107
Views: 86260

Mike,

Cool looking divergence on the exhaust. Good luck!

cudabean
by cudabean
Fri Jan 09, 2004 3:24 am
Forum: Valved pulsejet forum
Topic: Printed Valves
Replies: 7
Views: 4834

Why not EDM? Electrical Discharge Machining. Perhaps slightly more trouble than a chemical process because you first need to create a metal electrode. The electrode is simply a negative shaped "die" that you apply electricity to and it slowly eats away the metal material as it sinks through your sta...
by cudabean
Fri Jan 09, 2004 2:13 am
Forum: Tools and Construction
Topic: PIC microcontrollers
Replies: 0
Views: 2762

PIC microcontrollers

There was a discussion on PICs in the off-topic forum a few days ago. I just did a search and it looks like you can cross-compile a PIC program on your PC using gcc (GNU C compiler), which is free and should be runnable in windows using Cygwin. Anyone have any experience (good/bad) with this? cudabean
by cudabean
Thu Jan 08, 2004 12:21 am
Forum: Valveless pulsejet forum
Topic: New engine -- SP 14
Replies: 95
Views: 53897

Nice. Thanks Bruno.

One question. I calculated the area of the exhaust (disregarding wall thickness) as being 387 mm2, but the intake area is 1225 mm2. Would this tend to make the intake be the primary exhaust?

cudabean
by cudabean
Wed Jan 07, 2004 5:27 am
Forum: Valveless pulsejet forum
Topic: New engine -- SP 14
Replies: 95
Views: 53897

Chris, That's nice. I like how you have streamlined it. My only suggestion would be to rearrange the exhaust so that it "hugs" the interior thereby heating the interior air passing through as much as possible, which should also help cool the exhaust and hopefully quiet it down a little. Here's a sli...
by cudabean
Tue Jan 06, 2004 12:40 am
Forum: Valveless pulsejet forum
Topic: SP-14 as ram hybrid
Replies: 11
Views: 6360

What I am after is a low-speed ramjet. An engine that craetes its own ram pressure, at standstill if need be. Hmm, yeah, I think I see what you're saying. Maybe, in the case of a lockwood type, the short lockwood "intake", if it didn't poison the air too much, could double as a pressure generator d...
by cudabean
Mon Jan 05, 2004 9:49 pm
Forum: Valveless pulsejet forum
Topic: SP-14 as ram hybrid
Replies: 11
Views: 6360

Why do you think I like the annular configuration so much?
What? They allow super-sonic ultralights in Croatia? What a deal! ;)

cudabean
by cudabean
Mon Jan 05, 2004 6:11 pm
Forum: Valveless pulsejet forum
Topic: SP-14 as ram hybrid
Replies: 11
Views: 6360

SP-14 as ram hybrid

Didn't want to distract the main SP-14 thread, so I thought I'd start a new thread for this tangential idea. It seems to me that it would not be too difficult to create a ramjet hybrid out of Bruno's SP-14. I guess you would perhaps equip the motor with a central spike for a compressor and allow it ...
by cudabean
Mon Jan 05, 2004 12:02 am
Forum: Valveless pulsejet forum
Topic: New engine -- SP 14
Replies: 95
Views: 53897

Insideout? How about calling it an anular lockwood? One feature I particularly like about it is it seems to have a built in thrust augmentor that admits fresh air and heats it up, then mixes with the exhaust. This would probably help keep the noise down some because all of your high velocity hot gas...
by cudabean
Tue Dec 30, 2003 1:05 am
Forum: Valveless pulsejet forum
Topic: Kazoo II
Replies: 7
Views: 4650

Re: Kazoo II

The reason for a continuous taper is that any sudden change of section generates wave reflections. Constant section and constant taper diffuser don't. If your design already generates all the reflections you want, well, then you want to avoid any additional points at which a reflection can occur. S...
by cudabean
Sun Dec 28, 2003 9:52 pm
Forum: Valveless pulsejet forum
Topic: Kazoo II
Replies: 7
Views: 4650

Kazoo II

One thing that I've noticed about Lockwoods is the main exhaust is a continuous taper from the exhaust to combustion chamber. What's that about anyway? Mike, do you plan to implement that in the Kazoo? If so, will you be able to control the squish so that your cross sectional area diminishes as it g...