On 06/05/2010 08:02 PM, Robert Borger wrote:
> Once the air has been
> heated by the first radiator its ability to accept heat from the second
> has been greatly reduced if not eliminated.
Ok, thanks everyone! The picture is much more clear to me now. It seems
that splitting up the oil and water radiator is the way to go.
About a month ago, the system was working quite ok. Amazing how little
OAT difference can spoil the setup.
When I saw the Europa radiator setup for the first time, I had some
doubts about it. But because the Europa lacks a thermostat, I figured
that the oil cooler behind the water radiator was on purpose, to prevent
the oil temps from dropping too low. The manual explicitely calls for
"hot climats" to use the "option" to lower the oil radiator. With
hindsight, I think this description is somewhat misleading.
As some have noticed, I trimmed down the cooling duct considerably,
added a diffuser, added a cowl flap, to optimize both aerodynamics and
cooling capacity. Although it seems my ship is indeed quite fast for a
tri-gear, the oil cooler is not going to work efficiently this way. Too
bad that I don't have room to lower the oil radiator, so I'm going to
have to relocate the oil cooler. I now appreciate the term "experimental
airplane". :-S
Some have mentioned that the exit area of the cowling might be a
problem. However, so far I have no indication that the exit area is the
bottleneck. In area it is bigger than the inlet, and I have no signs of
elevated cowling temperatures like discoloured spark plug labels. Also,
some experiments to open up more cowl space had zero effects on the
temperatures.
I'm glad to hear that the Rotax shroud isn't a necessary item.
Thanks everyone!
Frans
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