A New Friend and a New Lady

Moderator: Mike Everman

Re: re: A New Friend and a New Lady

Postby Stuart » Fri Dec 09, 2005 10:01 am

serverlan wrote:Hi Ed,

I can offer just one piece of info.

The colour of the flame indicates its temperature.
I can't remember the exact figure now, but lets say its about 2100K
If the intake temperature is 300K, then the combustion raises the temperature by a factore of 7:1.
If it burns fast enough to achieve this temperature before the pressure disperses, we could expect a similar increase in pressure above atmospheric.
Thus the initial burn pressure could be up to 700000 whatever-the-metric-units-are.

If the gas were to expand as it is burning (i.e. a slower burn) then that temperature would not be reached (expansion produces cooling) and the temperature would be lower and the colour different. So, at the moment I think that is a reasonable pressure estimate. Most people tell me I'm dreaming, that the measured pressure peaks are much less than that.


700,000 whatevers would be 700,000 Pascals or 700,000 Pa. Or in friendlier terms, 7 atmospheres. Except, no Pjet engine gets the full charge to that temperature. Published figures for the Argus only show a total cycle fluction of around two atmospheres, and part of that is in the negative inflow region (below 1 atmosphere).

Pulse detonation, on the other hand, gets local shock temperatures that are to the moon, but those aren't the same as average temps.
I'm writing an automated airplane designer in java, useful later when you guys get ready to bolt a p-jet onto some wings
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Re: re: A New Friend and a New Lady

Postby Carl Litzkow » Mon Dec 12, 2005 1:23 pm

Larry Cottrill wrote:Carl -

Make sure what you present is really applicable in some way to propulsion theory, and doesn't come across as encouraging amateur explosives experimentation. That goes down pretty badly here (even in the Off Topics Forum). I'm sure you'll use good sense; this is just a "word to the wise".

L Cottrill

Trust me on this one my friend, I am very conscience of NOT encouraging the "crazy's" or giving the Forum a negative "personality". I should have said I was trying to provide another design tool, and not emphasized his credentials. He knows it is for PJ propulsion. Most of this thread seemed to be in finding an alternative to UFLOW since no code or upgrades are available. I will censor @ my end and always intended for you to screen before you post. I will e-mail my latest construction jpegs for FWE ver. V today.
Carl Litzkow
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The Lady Has a Flamboyant Flare

Postby larry cottrill » Tue Dec 13, 2005 3:02 pm

Carl sent this along last night. The new intake, with socket for replaceable end sections. He is also considering making the intake as a whole adjustable in terms of its position along the chamber cone, and I told him I'm in no hurry, if he wants to add that kind of flexibility.

This first attempt at a flare has a certain stylishness, and is reminiscent of the discussion Eric posted on his "suction pulsejet", though his big flare was at the tail, of course.

L Cottrill
Carl's initial FWE V intake configuration, with more-than-ample removable Nouveau Roccoco intake flare. Photo Copyright 2005 Carl Litzkow
FWE_V_Intake_Complete_crop1.JPG (47.12 KiB) Viewed 3464 times
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re: A New Friend and a New Lady

Postby Eric » Tue Dec 13, 2005 5:05 pm

Wow.... Maybe he should make a linear engine. Would be a bit easier to try out really huge flares and adjust intake length.


Talking like a pirate does not qualify as experience, this should be common sense, as pirates have little real life experience in anything other than smelling bad, and contracting venereal diseases
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re: A New Friend and a New Lady

Postby larry cottrill » Thu Jan 05, 2006 2:58 am

Here's Carl's first shot at the FWE V front end. With my blessing, he's decided on removable nose plates as well. This one is a sort of Durante shnozzola, all set to bolt right on.

Obviously, Carl takes a back seat to no one when it comes to craftsmanship! He also sent me a few shots of some nice art pieces he has done.

Also note his laboratory grade spark coil in the background (that varnished maple box with black screw terminals, upper left). Carl should be arm-twisted into making us a closeup shot of that, especially showing off the nifty buzzer assembly at the front end that makes it cook.

Thanks, Carl!

L Cottrill

"Yes, we are Cottrill Cyclodyne -
Our wheels grind slow, but exceeding fine."
First form of FWE V front end, with intake tube in place on the very long chamber cone. Photo Copyright 2006 Carl Litzkow
FWE_V_front_end_mod1_crop1.JPG (35.17 KiB) Viewed 3369 times
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Materials & Methods: Cylinder Head

Postby larry cottrill » Fri Jan 06, 2006 4:24 pm

Making the "cylinder head" (removable chamber dome) - cleverly crafted from a protective cap as featured on standard high-pressure gas cylinders. Should be sufficiently heavy duty for pulsejet work.

L Cottrill
This view shows how the chamber head was cut from a standard cylinder cap. Photo Copyright 2006 Carl Litzkow
FWE_V_cyl_head_cut_crop1.jpg (59.94 KiB) Viewed 3340 times
Grinding the cut chamber head. This gives us some idea of Carl's shop setup. Photo Copyright 2006 Carl Litzkow
FWE_V_grinding_cyl_head_crop1.jpg (188.98 KiB) Viewed 3341 times
All set to start cutting the big hole in the center of the flanges. Might take a little cutting oil! Photo Copyright 2006 Carl Litzkow
FWE_V_hole_saw_flange_01_crop1.jpg (131.85 KiB) Viewed 3340 times
All finished with the hole saw. Photo Copyright 2006 Carl Litzkow
FWE_V_hole_saw_flange_02_crop1.jpg (186.55 KiB) Viewed 3339 times
Final step on flanges is to cut them to convenient octagonal shape on the band saw. Photo Copyright 2006 Carl Litzkow
FWE_V_cutting_flange_crop1.jpg (120.87 KiB) Viewed 3340 times
Finished combustion chamber head, with candidate spark plugs. Photo Copyright 2006 Carl Litzkow
FWE_V_cyl_head_&_plugs_crop1.jpg (126.39 KiB) Viewed 3342 times
Rear view of finished head with short plug installed, long plug at rest waiting its turn. Photo Copyright 2006 Carl Litzkow
FWE_V_head_short_plug_installed_crop1.jpg (113.09 KiB) Viewed 3341 times
larry cottrill
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Materials & Methods: Intake and Cones

Postby larry cottrill » Fri Jan 06, 2006 4:35 pm

A few more shots: making the intake and drilling the port in the chamber to fit it; the tail cone; all parts together on workbench.

L Cottrill
Cutting off the required length of curved intake tube from EMT bend, using the band saw. Photo Copyright 2006 Carl Litzkow
FWE_V_cutting_EMT_sweep_crop1.jpg (111.69 KiB) Viewed 3341 times
One EMT bend supplies two identical intake tubes. Photo Copyright 2006 Carl Litzkow
FWE_V_2_intakes_from_EMT_bend_crop1.jpg (149 KiB) Viewed 3337 times
Somewhere along the line you have to face up to cutting the intake hole in the chamber cone. Here's the right way to do it. Photo Copyright 2006 Carl Litzkow
FWE_V_cutting_intake_port_crop1.jpg (163.12 KiB) Viewed 3339 times
Tailpipe end cone (long flare) with integral rear support. Photo Copyright 2006 Carl Litzkow
FWE_V_tailpipe_flare_crop1.jpg (131.11 KiB) Viewed 3340 times
All finished parts gathered up on Carl's workbench. Photo Copyright 2006 Carl Litzkow
FWE_V_parts_on_bench_crop1.jpg (191.69 KiB) Viewed 3337 times
larry cottrill
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re: A New Friend and a New Lady

Postby El-Kablooey » Fri Jan 06, 2006 8:34 pm

Wow, I hope that runs as good as it looks!
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Fuel Stinger Details

Postby larry cottrill » Wed Jan 18, 2006 2:34 pm

Well, Carl just sent me four more shots, this time of the fuel stinger setup. He didn't say whether he settled on 1/4-inch or 3/16-inch OD brake line for the stinger, but it's one or the other of those, with a flattened nozzle on the business end, as shown below. The depth of the stinger in the straight upper part of the intake is fully adjustable (possibly even while running, it seems to me).

I sent him an email suggesting that he complicate things a little more by providing a parallel tube connected to a manometer, so we can get pressure / suction values in the intake as the stinger is adjusted to different positions. We'll see if he takes me up on this. I think that would be interesting data to collect once he gets her running.

L Cottrill
.030 inch - seems to me like a perfectly fine number to use for the size of a fuel spout. Photo Copyright 2006 Carl Litzkow
FWE_V_fuel_stinger_30_thousandths_crop1.jpg (32.22 KiB) Viewed 3225 times
How centering of the adjustable fuel stinger is achieved. Photo Copyright 2006 Carl Litzkow
FWE_V_fuel_stinger_centered_crop1.jpg (44.97 KiB) Viewed 3227 times
The adjustable stinger all the way out ... Photo Copyright 2006 Carl Litzkow
FWE_V_fuel_stinger_out_crop1.jpg (45.16 KiB) Viewed 3224 times
... and all the way in. Photo Copyright 2006 Carl Litzkow
FWE_V_fuel_stinger_in_crop1.jpg (45.85 KiB) Viewed 3225 times
larry cottrill
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re: A New Friend and a New Lady

Postby hagent » Wed Jan 18, 2006 3:41 pm

Nice looking shop Larry!

It's nice to have all the tools.

I like the PJ too.

Nice gold touch.

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