All the better. I believe that someone who is NEVER WRONG on some other list, told me it was 3 inches. Thanks Tracy. Jerry


On Wednesday, April 13, 2005, at 07:50 PM, Tracy Crook wrote:

FWIW, my current scoop is 2.125" in diameter.
 
Tracy


I have not actually studied the ideal ram scoop opening. I know that
Tracy is using a 3inch dia round  scoop that would have about 7 inches
of area, just a little smaller than the scoop I proposed.  I want to
keep the scoop as low as possible while retaining the performance.  The
snouts that stick up into the air are not the look I want.  Does the
scoop get smaller with a higher top end?  What would it be for 240 mph?
    Jerry


On Tuesday, April 12, 2005, at 06:19 PM, Al Gietzen wrote:

>
> Here is pic of the plenum (at this point a piece of 1/4 inch ply.  The
> ram air scoop will be 4 inches wide and  two inches high.
>
> Jerry:
>
> Is the 2" x 4" the opening size?  I think that is more than double the
> area
> that would give the amount of ram air needed for a 2-rotor at, say,
> 120 kts.
> So it will be spilling air and likely cause some amount of unwanted
> drag.
> Ideally, a ram induction scoop is close to the area needed for near top
> speed; and have radius on the entrance lip (about that of your index
> finger)
> to minimize entrance loss when you are at low speed.
>
> FWIW, I have no idea it any of this matters for what you're doing.
>
> Al
>
>
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