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Old Jul 01, 2011, 05:10 AM
Avro Vulcan Enthusiast
United Kingdom, London
Joined Jun 2011
59 Posts
Many thanks for your advice Robert!

I have been reading this thread for help to convert the old pusher model! Though I had originally planned to use a large gauge (0.5mm) Aluminium foil for the jet pipe, I now think I will use paper as Terry has done

This is set to be a fun and difficult project, my only real concern is the wing attachment... I think I will be investing heavily in carbon fibre rods

-Edit- I notice Terry has tapered the jet pipes by about half an inch from the fan to the exhaust... Do I need to taper the pipe, does that assist in providing thrust?
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Last edited by bloodline; Jul 01, 2011 at 05:12 AM. Reason: Added question about ducting!
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Old Jul 01, 2011, 06:19 AM
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Joined Apr 2002
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The intakes need to be about 110% of the fan area (blade area less hub area) for an ROG model (100% for bungee) the eflux should reduce down to 85%.

With 4 to make, make a plug, then make Brown paper/PVA laminated tubes.
Look at Ron Laden's Eurofighter thread for details of that.
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Old Jul 01, 2011, 06:41 AM
Avro Vulcan Enthusiast
United Kingdom, London
Joined Jun 2011
59 Posts
Quote:
Originally Posted by Robert May View Post
The intakes need to be about 110% of the fan area (blade area less hub area) for an ROG model (100% for bungee) the eflux should reduce down to 85%.
With 55mm fans, that's a fan area (including hub) of 2376mm2, with two fans that's 4752mm2... And my intakes have an area of 6580mm2... So I should be good for the intakes... If i need 85% of the area for the exhaust... Then if my calculations are correct I would need the end diameter to be 50mm... Not much of a reduction... I assume I really do need to take into account the hub.

I don't have fan to hand to measure the hub size... I will rework my calculations again when I have.

Quote:
With 4 to make, make a plug, then make Brown paper/PVA laminated tubes.
Look at Ron Laden's Eurofighter thread for details of that.
Brilliant stuff, thanks again.

Another question, sorry I have so many... Is there any advantage to have smooth (I.e. Polished) bore jet pipes, or would any advantage be negligible?
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Old Jul 01, 2011, 07:05 AM
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I use rolled 0.3mm epoxy glass sheet for my ducts which is polished as a result of production.

As our models are comparatively flying through treacle anything you can do will help but that said, a finished bad model flies a heap better than a polished unfinished one.
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Old Jul 09, 2011, 04:20 AM
Avro Vulcan Enthusiast
United Kingdom, London
Joined Jun 2011
59 Posts
My build has started

I will be constructing the fuselage central section conventionally, then once glued I will remove the bulkhead that foul my fan ducts and reenforce the sections with carbon-fibre.

My only concern now is the wing attachment. My current idea is to use 3 carbon-fibre rods that extend across the fuselage, two up front (top of the wing and bottom of the wing) which will also be the engine mounts and one at the rear of the wing.

Other than the wing attachment, I don't plan any modification to the wing design.

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Old Jul 09, 2011, 10:35 AM
Avro Vulcan Enthusiast
United Kingdom, London
Joined Jun 2011
59 Posts
A couple of photos, the first is a test fit of the Port Wing Ribs... I love the undercamber at the edge of the wing!

The second photo is a rough sketch of the cuts I will be making to the bulkheads to accommodate the EDF ducts. The ducts get gradually lower down the panels and sit in the Jet pipe mouldings under the wing.
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Old Jul 10, 2011, 02:49 AM
smithy
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Cornwall, UK
Joined Dec 2004
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Really looking forward to this build, good luck. Went to see XH558 at Yeovilton yesterday.

Phil
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Old Jul 10, 2011, 08:47 AM
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shut up Phil. LOL

don't you have a plane to build?
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Old Jul 10, 2011, 12:45 PM
Avro Vulcan Enthusiast
United Kingdom, London
Joined Jun 2011
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I saw XH558 earlier this year at Abingdon... See attached, and will see her again on the 16th at Fairford...

I also "accidentally" saw her at Margate, while visiting my girlfriend's grand parents... no idea how that happened


[youtube]YxFojmjxf_w[/youtube]

airshow.MP4 (0 min 28 sec)
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Old Jul 10, 2011, 01:09 PM
Avro Vulcan Enthusiast
United Kingdom, London
Joined Jun 2011
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Attached is a photo of my modification to bulkhead F6A to allow a real air intake. I will sand the Square hole into a nice smooth curve and build a nice smooth air duct with some lightweight filler.
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Old Jul 11, 2011, 02:47 AM
smithy
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Cornwall, UK
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Quote:
Originally Posted by LuvEvolution7 View Post
shut up Phil. LOL

don't you have a plane to build?
Yeah yeah i know, nearly there.

Gotta love that Vulcan 'howl' from those Olympus's, wonder how you could recreate that with edf's?

Phil
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Old Jul 11, 2011, 03:05 AM
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ummmmmmmmmm, I'm guessing some type of heavy liquid injection. although, I doubt the electronics would last very long. then again, the smoke trail would look really cool.
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Old Jul 11, 2011, 11:00 AM
Avro Vulcan Enthusiast
United Kingdom, London
Joined Jun 2011
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Perhaps a free spinning fan (with carefully placed distuptive stators - much like the old air raid siren) sitting in front of the EDF could simulate the spool up whine...? It would eat up a fair bit of the EDF's efficiency though :-/
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Old Jul 12, 2011, 03:03 PM
EDF Vulcan To The Sky
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Near Koblenz, Germany
Joined Jul 2002
191 Posts
Nice work bloodline! I almost finished my 65 inch wingspan Twin EDF Vulcan (90 mm) build from the Cyril Carr plans. Here are are a couple of pics posted including the wing attachment at my model. The weight is 5,25 kg and the wing attachment works great. Of course I will not try snap rolls with this construction, but scale-like flying is no problem at all.

http://www.modelflying.co.uk/albums/...ms.asp?c=73594

Frank
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Old Jul 12, 2011, 04:22 PM
Avro Vulcan Enthusiast
United Kingdom, London
Joined Jun 2011
59 Posts
Quote:
Originally Posted by Radar-Guy View Post
Nice work bloodline! I almost finished my 65 inch wingspan Twin EDF Vulcan (90 mm) build from the Cyril Carr plans. Here are are a couple of pics posted including the wing attachment at my model. The weight is 5,25 kg and the wing attachment works great. Of course I will not try snap rolls with this construction, but scale-like flying is no problem at all.

http://www.modelflying.co.uk/albums/...ms.asp?c=73594

Frank
Beautiful model! I hope mine will look even half as good... Though I doubt it... my next one will be better

Also, scale flying is the plan... I don't want an engine with wings! :-D

Here is a photo of my fan duct template (held by my girlfriend to make the photo more interesting), I am cutting this out of the bulkhead to and mounting the fan behind... I can provide measurements/specs and templates if anyone else needs them.
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