REFLECTOR: Fwd: My Velocity setup

[Jim Sower]

Probably. I've seen such a setup on a Long-EZ and the guy swears by it.


ouglas Holub wrote:

> Would it help to suck air through the NACA ducts if I put a fan on the 
> prop extender just before it exits the cowl?
> Doug Holub
>
>     ----- Original Message -----
>     *From:* Al Gietzen <mailto:ALVentures at cox.net>
>     *To:* 'Velocity Aircraft Owners and Builders list'
>     <mailto:reflector at tvbf.org>
>     *Sent:* Friday, December 03, 2004 10:54 AM
>     *Subject:* RE: REFLECTOR: Fwd: My Velocity setup
>
>     My idea behind this is to scavange some of the flow that comes
>     through the bottom radiator, across the bottom of the pan, and out
>     the "suction slot". at about 18" from the center of prop rotation,
>     it should also add to the suction the prop places on the cowl
>     opennings. Well.. at least that is my idea, we'll see if it works
>     out. I am hoping that I can get away without an oil cooler with
>     that setup. No worries though, I have a backup to put an inline
>     cooler on the #2 NACA scoop if I need it.
>
>     Keep in mind that the reduced pressure (“suction”) generated by
>     the prop dissipates rapidly (exponentially) as you move away from
>     the prop, so even a foot is a long way - and at cruise it is
>     almost non-existent; you have to rely on dynamic pressure and
>     whatever gradients are produced by the flow. Remember, the air is
>     standing still, the airplane is moving. Some air is getting
>     pushed/pulled downward by the airfoils, some is being pushed back
>     by the prop, the rest is getting out of the way as best it can.
>
>     Al
>
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>