REFLECTOR: Use of VGs toaid cooling

David Ullman via Reflector reflector at tvbf.org
Tue Sep 30 15:24:33 CDT 2014


I did not play with spacing.  I used what I found in the reference in the paper.  I had already taken about 20 data points (not all in the article) and was ready to finish.  I could have tinkered more with spacing and position in front of the NACA ducts.  But, it was time to quit and I had good enough temperatures.  I am sure there is more to be had.  No way did I find the sweet spot on the first try. 

I initially used bent Al and riveted them on.  When they worked I took them off, ground off the finish on the roof down to glass and used cyanoacrylate to glue on thin pieces of premade fiberglass sheet cut to shape (you can get sheets already made in varying thicknesses).  I then 2-bid each side with a flange onto the roof, filled sanded a repainted the roof.  There are no flanges to be seen as they are flush with the roof. I work with a painter who is a master at touching up changes so you cant ever see them.  We use a pigment coat and a clear coat.  We also put a lot of things together with super glue and accelerator.  You can work really fast and then glass over for strength.    Just take care when you sand, the dust is an irritant to eyes and nose. 

 
David Ullman
N444DX
President EAA 292
541-760-2338
david at davidullman.com




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Sent: Tuesday, September 30, 2014 12:27 PM
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Today's Topics:

   1.  paint temp (Alex Balic via Reflector)
   2. Re:  The use of VG to aid cooling (Lawrence Epstein via Reflector)
   3.  Rough River lost and Found (Jeff Barnes via Reflector)
   4.  Fwd: Re:  The use of VG to aid cooling
      (Brett Ferrell via Reflector)


----------------------------------------------------------------------

Message: 1
Date: Tue, 30 Sep 2014 12:41:36 -0500
From: Alex Balic via Reflector <reflector at tvbf.org>
To: "'David Ullman'" <ullman at robustdecisions.com>, "'Velocity Aircraft
	Owners and Builders list'" <reflector at tvbf.org>
Subject: REFLECTOR: paint temp
Message-ID: <04ef01cfdcd5$c8bb0c00$5a312400$@net>
Content-Type: text/plain; charset=us-ascii

Hey Dave, how does that dark blue paint on the canard tips do for getting hot while on the ground?

Alex

-----Original Message-----
From: Reflector [mailto:reflector-bounces at tvbf.org] On Behalf Of David Ullman via Reflector
Sent: Monday, September 29, 2014 7:09 PM
To: reflector at tvbf.org; reflector-request at tvbf.org
Subject: REFLECTOR: The use of VG to aid cooling

My Velocity has always run hot.  I have fixed this with the use of Vortex Generators aiding the flow of air into the NACA ducts on top of the fuselage.  For a full report go to:

https://davidullman.com/uploads/THE_USE_OF_VORTEX_GENERATORS_TO_ENHANCE_PUSH
ER_AIRCRAFT_COOLING.pdf

Comments appreciated.

To see recent photos of N444DX hangared in Independence Oregon, go to: 

https://davidullman.com/VelocityPhotos.php

David Ullman
David at davidullman.com



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Message: 2
Date: Tue, 30 Sep 2014 13:42:16 -0400
From: Lawrence Epstein via Reflector <reflector at tvbf.org>
To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
Subject: Re: REFLECTOR: The use of VG to aid cooling
Message-ID:
	<CAHU3DNu8Wd0gSiGxg3sWfW-Npzx8AK58ZVOtQzBc4Bkqg1=H_g at mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Great study.

Have you looked at the effect of varying the spacing between the VG's (I didnt see that in your article). Kurt Winkler said that he saw dramatic differences when he varied the spacing.

Larry

On Tue, Sep 30, 2014 at 12:56 PM, Ron N VelocityXLFG via Reflector < reflector at tvbf.org> wrote:

> Great Job ! . But now I ask the question how is it so many builders 
> claim the small vg's help when your info so clearly says it does not. 
> I have small vg's  in front of my nacas
> and was sure they helped till now. :(   I have now put testing my naca
> intake back on the testing list. Oh well more fun things to experiment 
> with
> :-) .
>
> Great article so loaded with great info.
>
>
> Ron
>
>
>
> On 9/30/2014 8:48 AM, Matt Bucko via Reflector wrote:
>
>> Well done David.
>> Matt
>>
>>
>> On 9/29/2014 5:09 PM, David Ullman via Reflector wrote:
>>
>>> My Velocity has always run hot.  I have fixed this with the use of 
>>> Vortex Generators aiding the flow of air into the NACA ducts on top 
>>> of the fuselage.  For a full report go to:
>>>
>>> https://davidullman.com/uploads/THE_USE_OF_VORTEX_
>>> GENERATORS_TO_ENHANCE_PUSHER_AIRCRAFT_COOLING.pdf
>>>
>>> Comments appreciated.
>>>
>>> To see recent photos of N444DX hangared in Independence Oregon, go to:
>>>
>>> https://davidullman.com/VelocityPhotos.php
>>>
>>> David Ullman
>>> David at davidullman.com
>>>
>>>
>>>
>>> _______________________________________________
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>>> tvbf:jamaicangoose Check new archives: www.tvbf.org/pipermail Check 
>>> old archives: http://www.tvbf.org/archives/velocity/maillist.html
>>>
>>
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>
> _______________________________________________
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> listinfo/reflector
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Message: 3
Date: Tue, 30 Sep 2014 11:38:12 -0700
From: Jeff Barnes via Reflector <reflector at tvbf.org>
To: canard-aviators <canard-aviators at yahoogroups.com>, Velocity
	Reflector <reflector at tvbf.org>
Subject: REFLECTOR: Rough River lost and Found
Message-ID:
	<1412102292.13398.YahooMailNeo at web181506.mail.ne1.yahoo.com>
Content-Type: text/plain; charset="utf-8"

Hi Folks, 


   I misplaced a John Lambert Canard RACE book and an Icom handheld I purchased from John.

   Am wondering if I left them in food tent, bathroom or sat them on ramp as I got into my RV-6 to depart. I was parked Saturday next to the Defiants. 


   Any info would be helpful - altho they could still be in my Bermuda triangle hangar.

Thanks,

Jeff Barnes
847-331-2567
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Message: 4
Date: Tue, 30 Sep 2014 15:52:30 -0400
From: Brett Ferrell via Reflector <reflector at tvbf.org>
To: "reflector tvbr.org" <reflector at tvbf.org>
Subject: REFLECTOR: Fwd: Re:  The use of VG to aid cooling
Message-ID:
	<1412106750.3346841.173605453.2F4214E3 at webmail.messagingengine.com>
Content-Type: text/plain; charset="utf-8"

David,



I concur, great work.  I can't tell from your pictures, but I assume your VG's have "feet"?  They really look like they just come out of the roof, so well done there.  I'm keen to make a set, did you just use like 3 BID against some of your i-Beam AL to get make them?



Brett
--
Brett Ferrell
[1]bferrell at fastmail.fm




On 9/29/2014 5:09 PM, David Ullman via Reflector wrote:

  My Velocity has always run hot.  I have fixed this with the
  use of Vortex Generators aiding the flow of air into the
  NACA ducts on top of the fuselage.  For a full report go to:
  [2]https://davidullman.com/uploads/THE_USE_OF_VORTEX_GENERAT
  ORS_TO_ENHANCE_PUSHER_AIRCRAFT_COOLING.pdf
  Comments appreciated.
  To see recent photos of N444DX hangared in Independence
  Oregon, go to:
  [3]https://davidullman.com/VelocityPhotos.php
  David Ullman
  [4]David at davidullman.com
  _______________________________________________
  To change your email address, visit
  [5]http://www.tvbf.org/mailman/listinfo/reflector
  Visit the gallery!  [6]www.tvbf.org/gallery
  user:pw = tvbf:jamaicangoose
  Check new archives: [7]www.tvbf.org/pipermail
  Check old archives:
  [8]http://www.tvbf.org/archives/velocity/maillist.html



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References

1. mailto:bferrell at fastmail.fm
2. https://davidullman.com/uploads/THE_USE_OF_VORTEX_GENERATORS_TO_ENHANCE_PUSHER_AIRCRAFT_COOLING.pdf
3. https://davidullman.com/VelocityPhotos.php
4. mailto:David at davidullman.com
5. http://www.tvbf.org/mailman/listinfo/reflector
6. http://www.tvbf.org/gallery
7. http://www.tvbf.org/pipermail
8. http://www.tvbf.org/archives/velocity/maillist.html
9. http://www.tvbf.org/mailman/listinfo/reflector
  10. http://www.tvbf.org/gallery
  11. http://www.tvbf.org/pipermail
  12. http://www.tvbf.org/archives/velocity/maillist.html
  13. http://www.tvbf.org/mailman/listinfo/reflector
  14. http://www.tvbf.org/gallery
  15. http://www.tvbf.org/pipermail
  16. http://www.tvbf.org/archives/velocity/maillist.html
  17. http://www.tvbf.org/mailman/listinfo/reflector
  18. http://www.tvbf.org/archives/velocity/maillist.html
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