REFLECTOR: Airfoils

Fri Dec 6 18:47:32 CST 2013

David,

You're probably right that there have been some variations in the canard shape over the years. I don't know if it helps with your research, but I'm including some cross-section photos of my hollow-core (aka Brazilian) canard before I put the wing-tips on. My understanding is that the molds for these canards were made from a standard factory-built foam-core canard, so they should be the same shape. (Side note, I added the clear plastic tube and string that you see in the photos so that I could later run wiring for canard-tip landing lights.)

[cid:image001.png at 01CEF2B7.48A4CD20]

[cid:image002.png at 01CEF2B7.48A4CD20]

I'll send you high-res versions via email.

Reiff Lorenz, Dayton, OH
Velocity XL-RG, 51% complete
Currently working on: Cabin heat ducting

Velocity Owners and Builders Association
http://www.VelocityOwners.com<http://www.velocityowners.com/>

The Velocity Builders' Virtual Hangar is available 24/7 at:
https://liveconferencepro.com/guest/loginguest.php?id=86a48563bb517ade0abf1a7ee1f38e65

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf Of David Ullman
Sent: Thursday, December 5, 2013 10:43 PM
To: reflector at tvbf.org
Subject: REFLECTOR: Airfoil

Reiff,

Thanks for the background.  I will measure up my airfoil and see what I come up with.  I suspect that each of us have a different shape(s) (the "s" is for root to tip variation).  I will keep all informed of the result of my modeling.  This is one of my winter projects, besides finally painting 444DX (which has about 100 hours on her).

Date: Thu, 5 Dec 2013 19:41:39 -0500

From: Reiff Lorenz <Reiff at Lorenz.com<mailto:Reiff at Lorenz.com>>

To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org<mailto:reflector at tvbf.org>>

Subject: Re: REFLECTOR: Airfoils

Message-ID:

                <BFD8FEA9F3C5194597CF740E290D0DFA223D3F621A at tlc10.lorenz.com<mailto:BFD8FEA9F3C5194597CF740E290D0DFA223D3F621A at tlc10.lorenz.com>>

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>> Anyone know of the Airfoil sections on the wing and canard?  <<

David,

Many in the Velocity community will tell you that the Velocity airfoils are TLAR designs . . . that Danny Maher shaped them until "They Look About Right!" Funny story, but I think there's a more accurate description.

Danny built 2 Long EZs before creating the Velocity. The Wiki's unofficial history<http://wiki.velocityoba.com/index.php?title=UnOfficial_Velocity_History> of the Velocity claims that the Velocity wings are "modified Long-EZ

airfoils with Roncz vortilons added." This makes sense, given the designer's history. I had tried to find more information on the canard design, but was unable to find any magazine articles or online sources that referenced it.

I ran into Danny Maher when I was in Sebastian for Head Start in 2012. I asked him about the Velocity's airfoils. He confirmed the wings were "modified Long-EZ," adjusted to the larger plane he wanted.  He could not give me specifics on the "adjustments," perhaps lending some truth to the TLAR story. When asked about the canard, he said that at the time he was designing the Velocity, the Rutan canard community was struggling with the Glasgow University (GU) canard's problem with losing lift when "contaminated" with rain drops. Danny's neighbor at the airport had an old German glider that was in disrepair. Danny claimed that the Germans made some of the best-performing airfoils in the world, so modeled his canard off of the glider's horizontal stabilizer, scaled up to the appropriate size (and inverted, obviously). I tried to get details on the make and model of the glider, but Danny couldn't recall. I even asked if the plane's remains were still in the area, but they had been removed long ago. I didn't pursue this any further; just added a few details about the canard to the wiki and moved on.

I don't know if this helps with your model, but either way I thought you'd find it interesting.

Would love to hear more about your research, analysis, and modeling. Maybe post something here or send me a longer write-up and high-res images for the newsletter?

Thanks!

Reiff Lorenz, Dayton, OH

Velocity XL-RG, 51% complete

Currently working on: Exhaust routing

Velocity Owners and Builders Association http://www.VelocityOwners.com<http://www.velocityowners.com/<http://www.VelocityOwners.com%3chttp:/www.velocityowners.com/>>

The Velocity Builders' Virtual Hangar is available 24/7 at:

https://liveconferencepro.com/guest/loginguest.php?id=86a48563bb517ade0abf1a

7ee1f38e65

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