REFLECTOR: interference drag

[Lawrence J. Epstein, MD]

My plan was to do something similar, but make the fairing an independent
piece, that could be removed. More importantly, I would leave a gap
((3/16"?) on each mating surface and fill the gap with silicone. That
would allow for flex.

 

Larry Epstein

 

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of RBrim
Sent: Tuesday, November 20, 2007 5:05 PM
To: 'Velocity Aircraft Owners and Builders list'
Subject: Re: REFLECTOR: interference drag

 

Doug,

We proceeded down the same path on my plane, built in 1998.

I couldn't tell that it picked up any speed, but it sure looks better.  

There is one problem, the 2 bid tends to be too thin and it cracks,
especially around where the nutplates are, there's a little too much
vibration going on back there for 2 bid, so suggest you beef it up a
little.

 

Rodney Brim, 

CEO, Performance Solutions Technology, LLC

(707) 487-3000

 

From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Douglas Holub
Sent: Tuesday, November 20, 2007 1:43 PM
To: Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: interference drag

 

Thanks for the heads up. I'm not using it for strength, though, just for
a fairing. I glassed the strake to the fuselage normally, then poured
the foam and shaped the fillet, then put two plies of BID over the
shaped foam fillet.

 

Doug

----- Original Message ----- 

From: Ken <mailto:kenb at velocityaircraft.com>  C. Baker 

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

Sent: Tuesday, November 20, 2007 2:25 PM

Subject: Re: REFLECTOR: interference drag

 

Doug,

 

Looks good! A word of caution though - most of the pour foams available
on the market, even the very good ones, do not make good structural
cores. They have very low pcf ratings, and during crystallization they
form irregular cell structures. As well, they are prone to soft spots.
They're great for shaping things that you will ultimately glass over -
but it's important to remove the pour foam, and replace it with a
structural core like 3/8" divinycell, then glass the other side. In
other words, it's important to get that sandwich structure back in there
- especially at a critical structural union like the strake/fuselage
junction.

 

Happy Building,

 

-Ken Baker

kenb at velocityaircraft.com

XL-RG Hybrid-5 in Progress

 


  _____  


From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Douglas Holub
Sent: Tuesday, November 20, 2007 12:00 PM
To: reflector at tvbf.org
Subject: REFLECTOR: interference drag

I used pour foam to fill in the intersection between the strake and the
fuselage, then shaped it with some 40 grit sand paper glued around a
Clorox bottle. Here's what the fillet looks like with a Clorox bottle
radius. By doing the top and bottom of the wings, strakes, and winglet
intersections this way, I'm hoping to pick up a few extra mph.

 

Doug Holub


  _____  


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