| Hi Le Roux
Those diagrams relate to Streamline Diffusers, rather than the entrance lip shape that Finn is chasing.
Steve
Finn: Has come onto these pictures. Maybe can help in figuring out the coordinates or help solving the X and Y
Le Roux
Thanks. I guess I kept missing it
because I don't understand what I'm looking at.
Can anyone help me understand the following and show me the
optimum inside/outside radius ratio (which I assume is one of the
A-10 to A-40 contours):
<nadfchpfafimnegl.png>
<kbdejbnihmgdehea.png>
Finn
On 6/30/2021 9:45 PM, Charlie England ceengland7@gmail.com wrote:
Seems likely; I don't recall seeing a
CR3485 referenced anywhere, either.
On 6/30/2021 4:42 PM, Finn Lassen finn.lassen@verizon.net
wrote:
I tried in vain to find NASA_CR3485
(well, I found a NASA contractors report on animal
studies).
I wonder of he meant 3405?
<bnmfmdnlndmefidc.png>
Anyone found a better match?
Finn
On 4/28/2011 9:07 AM, Tracy wrote:
Finally
got around to finishing my cooling inlets. (pictures
attached)� Up until now they were simply round pipes
sticking out of the cowl.�� The pipes are still
there but they have properly shaped bellmouths on
them.�� The shape and contours were derived from a
NASA contractor report (NASA_CR3485) that you can find
via Google.� Lots of math & formulas in it but I
just copied the best performing inlet picture of the
contour.�� Apparently there is an optimum radius for
the inner and outer lip of the inlet.�� There was no
change to the inlet diameters of 5.25" on water cooler
and 4.75" on oil cooler.
The simple pipes performed adequately in level flight at
moderate cruise settings even on hot days but oil temps
would quickly hit redline at high power level flight and
in climb.�
The significant change with the new inlet shape is that
they appear to capture off-axis air flow� (like in
climb and swirling flow� induced by prop at high
power)� MUCH better than the simple pipes. ��
First flight test was on a 94 deg. F day and I could not
get the oil temp above 200 degrees in a max power climb.
�� They may have gone higher if the air temperature
remained constant but at 3500 fpm the rapidly decreasing
OAT kept the temps well under redline (210 deg F).
I have an air pressure instrument reading the pressure
in front of the oil cooler and was amazed at the
pressure recovered from the prop wash.� At 130 MPH the
pressure would almost double when the throttle was
advanced to WOT. � That did not happen nearly as much
with the simple pipes.��
These inlets ROCK!
Tracy Crook
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