REFLECTOR: Wing-root cooler re-visited

[Dennis Martin]

Hi Al,

I almost went with 1/4" boundary layer but decided to go with a bit more BL
tolerance based on advice from Malcolm Collier and Alan Shaw - they used a
bigger BL on their original oil cooler design. My letter box slots into the
wing root are a bit smaller than the mouth of the scoops to help slow down
the air flow. Outlet holes on top of wing are about 20% bigger than the
inlets. I tried to get an "S" curve design like you have in your system.
Mine is not as smooth and pretty inside the wing as your design, but
hopefully the "S" curve will work. The hot air exit tunnel on the top will
hopefully create a vacuum - it's about 3" above the wing surface and
aerodynamic like the bottom scoops.

You reported much better cooling when you got the scoops installed. Do you
have two radiators (one in each wing root?) I know you added a radiator
inside the cowl as well as the oil cooler.

Happy Thanksgiving,
Dennis

On Tue, Nov 25, 2008 at 2:22 PM, Al Gietzen <alventures at cox.net> wrote:

>  Dennis;
>
>
>
> Very nice looking scoops.  Sure looks like they ought to work.
>
>  I did BL profile measurements just in front of the scoop entrance, and was
> surprised to find it only about ¼" to something very close to free stream.
> May have something to do with the gear doors in front stirring things up, or
> bleeding some off.
>
>
>
> Is the opening into the wing larger than the opening at the mouth of the
> scoop?
>
>
>
> Al
>
>
>
> -----Original Message-----
> *From:* reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] *On
> Behalf Of *Dennis Martin
> *Sent:* Sunday, November 23, 2008 4:03 PM
> *To:* Velocity Aircraft Owners and Builders list
> *Subject:* Re: REFLECTOR: Wing-root cooler re-visited
>
>
>
> Hello Al,
>
> Just saying thanks for all the testing you did on the wing root air scoops
> for your Mazda powered V. Thought I'd show you my new inlet scoops inspired
> by your testing. They are sculpted out of blue foam and covered with 2 bid.
> Based on design calculations from Malcolm Collier (Hangar 18) I created a
> 1/2" boundary layer bleed. The inlets resemble the mouth of a whale shark
> (14" wide X 2 1/4" height) but I'd rather er on the side of excess given the
> amount of heat generated on takeoff by a 400 HP Chevy. Took a full week to
> finish my scoops and I don't have the patience to do this job over again.
> Hopefully by combining two well ventilated wing root radiators with a heater
> core (third radiator) in the nose I may now have enough cooling capacity -
> especially following your lead of scooping the air more aggressively. I'm
> planning on upholstery in January and test flight as soon as possible
> thereafter with the hope of beating the summer heat.
>
> All the best,
> Dennis
>
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-- 
All the best,
Dennis
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