Proposed Design: SNECMA-tailed FWE 'Lady Guinevere' (TM)

[larry cottrill]

All right, gentlemen - here is one that UFLOW1D says will work, IF I estimated a reasonable cool gas temp for the SNECMA-style tail cone, even with the cone severely reduced in size as shown on the plan.

The hard part will be final tuning. There are basically only two practical things you can do, either: (1) Alter the intake length slightly; OR (2) Alter the straight mid-section WITHOUT changing the annular gap in the intake cone of the tail end.

Use whatever convenient fuel / starting method you're accustomed to at the intake. I will be delighted to engage comments and suggestions on this engine design.

L Cottrill

[Eric]

I think you should stick with a normal adv fwe style intake, or even a standard linear intake, otherwise you are going to have more unnecessary variables.

Eric

[larry cottrill]

I think you should stick with a normal adv fwe style intake, or even a standard linear intake, otherwise you are going to have more unnecessary variables.

Never satisfied ... and here, I thought you'd be pleased that it doesn't poke down inside the chamber ;-)

Well, sure I could do that, but what fun would that be? For me, this kind of intake doesn't even qualify as a real "variable" - I've seen one form of this work on the Fo Mi Chin II, another on the Smooth Lady and yet another on the Sveldt Lady that Greg put together from my kit "product". I've also seen a slight degree of nozzling (which this has) work OK, although you and others have argued that a straight pipe is actually better. So, I have no reason not to try it, except one: If a round pipe were used, the tuning would be easier - you could actually use a sliding-fit end flare so you could vary it.

Obviously, anyone who wants to try this is welcome to "simplify" the intake with a more conventional form. I just like to try for a "low profile" solution - and so far, I would argue that it has worked well for me.

L Cottrill

[Bruno Ogorelec]

I like it. Id really like to see it run. Shortening the length by means of augmentation is really something -- if it works well.

[larry cottrill]

For the teeming masses who can't wait to build this highly experimental Lady, here are the cone sheets. Dimensions derived from Eric's PJ Calculator, of course.

If you have a "standard" 96DPI printer, you can print these at 189% and that should give you HALF SIZE printouts that will each fit an 8.5x11 standard sheet. Then, you can scale these up x2 using a copier that will handle it. The actual scale of the patterns is 1 pixel = 1 mm.

Use the very outside tips of the heavy black line to cut the patterns (the very inside edge of the line for the intake port), and your pattern should be very close to the exact dimensions indicated.

L Cottrill

[larry cottrill]

I finally did the projections to get an intake plan and sheet pattern drawn up. For this one, I used my new "full size Metric" grid, so for most printers (96 DPI) this should print as a perfect full-size drawing. It should just fit on an 8.5 x 11 inch sheet.

Cut the steel sheet and make the conical rolls in the zones indicated by the light grey shading (see Section details A-A and B-B for clarification). Heat and hammer the flared end and then weld the piece in place to the chamber cone along the two long bottom edges. Finally, heat and hammer the front spout down to the front edge of the opening in the chamber cone and finish weld around the front to seal it up.

L Cottrill