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This would be Eric Westland. He did some oil trail tests and ended up
with much improved cooling using vortex generators 1" * 4" vortex
generators at 45 degrees to the airstream ahead of the NACA (or whatever
you want to call the plans Cozy scoop). The results are up on a web site
somewhere.
Based on his results I installed the same generators from day one. I
have no measurements with them not in place.
John Slade
aheaJames wrote:
> I read an article (don't remember where) about a fellow who placed two
> vortex generator tabs just in front of the NACA ducts. This improved
> efficiency quite a lot. He had to experiment a while to get it right;
> but, liked the results. I think it was on a Velocity or Cozy.
>
> This makes perfect sense. As I remember when I read the initial NACA
> report. The paper indicated that the duct was efficient for large
> volume flows which created little back pressure.
> Thus, my analysis of the operation is that the efficiency of the duct
> depends on a bit of local turbulence at the duct to break the local
> boundary layer. A high flow rate, as the original paper indicated
> and/or required, would do that. Also a set of vortex generators in
> front of the duct would also do the same.
>
> Second point: I believe that a reversed direction NACA scoop would
> make an excellent low drag exit port for the cooling air stream.
> Such a scoop design would tend to form a small low- drag partial
> vacuum at that point, allowing the exit scoop to literally help suck
> the air out. This would improve cooling efficiency I.E. NACA in, and
> ACAN out.
> I hold several patents, but I am not going to pursue this idea on that
> basis. I think it has a good possibility of being a very efficient
> low drag cooling system.
>
> If anyone tries it, please let us know your findings.
>
> Best Regards;
>
> James Freeman
>
>
>
> David Staten wrote:
>
>> I skimmed it.. Chris and I are actually considering armpit scoops for
>> cooling, but we still have this nagging urge to minimize deviations
>> from plans. I will go back and do more than just skim..
>>
>> All I saw was NACA's, Cooling and immediately thought of PL..
>>
>> Dave
>>
>> Bulent Aliev wrote:
>>
>>> You are right Bill. David did not read the whole article. Or he
>>> didn't want to hear it? :)
>>> Buly
>>>
>>>
>>>
>>> On Mar 9, 2006, at 8:58 PM, Bill Dube wrote:
>>>
>>>> I read that article as well. I had the same skepticism about the
>>>> NACA intake for cooling. My understanding is that with an NACA
>>>> inlet, you don't get the ram pressure you need to force air
>>>> through a high fin-count radiator. Am I wrong about this?
>>>>
>>>> Bill Dube'
>>>>
>>>> David Staten wrote:
>>>>
>>>>> At the risk of invoking PL's name, anyone else read this months
>>>>> Sport Aviation mag from EAA, and notice an article on cooling
>>>>> that seems to indicate that NACA's are acceptable and adequate
>>>>> for aircraft cooling needs? I have no idea regarding the authors
>>>>> credentials, and I no longer monitor PL's "newsletter".. I was
>>>>> curious more than anything else... Pauls reaction, others
>>>>> reactions, etc.
>>>>>
>>>>> Translation.. yes.. I'm stirring the pot/Trolling... I figure if
>>>>> we are using NACA's on the Velocity, that makes us somewhat of a
>>>>> NACA supporter..
>>>>>
>>>>> Dave
>>>>>
>>>>> --
>>>>> Homepage: http://www.flyrotary.com/
>>>>> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/
>>>>>
>>>>
>>>> --
>>>> Homepage: http://www.flyrotary.com/
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>>>
>>>
>>>
>>>
>>>
>>> --
>>> Homepage: http://www.flyrotary.com/
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>>>
>>
>>
>> --
>> Homepage: http://www.flyrotary.com/
>> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/
>>
>> .
>>
>
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/
>
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