Paul,
Forward those to all of us as I'm too interested in seeing them.
Regards,
Jeff R.
A258 - N128LJ / Gold Rush 176 hours down for annual & Mods.
On Mar 3, 2009, at 8:46 AM, Paul Atkinson wrote:
> <paullatkinson@talktalk.net>
>
> Frans
>
> You may be interested to know that Europa did some testing of several
> duct
> positions with a view to producing a mod along the lines of what you
> are
> doing. The aim being to improve cooling, reduce drag and improve the
> looks.
> Unfortunately it never got produced :-(
> I spoke to Andy Draper today and he is going to send me a drawing of
> the
> design that worked the best in terms of cooling. I will happily
> forward it
> to you when I get it.
> Regards
>
> Paul Atkinson
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Frans
> Veldman
> Sent: 02 March 2009 20:53
> To: europa-list@matronics.com
> Subject: Europa-List: Cowling mods
>
> Fred Klein wrote:
>
>> Frans...this sounds really interesting...cheers for getting rid of the
>> dog house...how bout some photos?
>
> I guess more people are interested in seeing some preliminary work
> that has
> been done.
> Note that a lot of work still needs to be done. It is a sort of
> "concept"
> that is ready now.
>
> The idea is to reduce drag, and improve cooling at the same time.
>
> Picture 1: the nasa-ducts in the top cowling. Inside is a deflector
> screen.
> The air is aimed between the front and read cylinders, cooling both
> efficiently and equally. The air is directed to the bottom, so the
> heated
> air will hopefully not collect in the top cowling. The air outlets
> (inlets?)
> on the side are closed off. If the engine is shut off, the remaining
> heat
> will find its way out via the nasa ducts which are actually higher
> than the
> side vents.
> Note that the front openings will be used for taxi & landing lights,
> and not
> as an air passage.
>
> Picture 2: the cooling inlet and diffuser for the radiators. The idea
> is
> here that the frontal area is reduced, the air inlet is in a better
> position
> in the propellor wash (important for cooling on the ground!), and drag
> is
> lowered because of the diffuser in front of the radiators.
> The area where the original air duct was, has been filled with blue
> foam,
> and then sanded until it had the shape the cowling should have. A few
> layers
> of bid (inside and outside) to make it strong. Some (a lot?) of filler
> is
> required to finalize it. The diffuser is also made from blue foam,
> shaped,
> and with two layers of bid.
>
> Picture 3: closeup of the diffuser. The area inside is funnel shaped
> with a
> round curve, but that is hard to see. Every wall of the diffuser can
> be seen
> as a wing. The air going inside is slowed down by expansion, to match
> with
> the airflow the radiators can handle.
>
> Picture 4: Underside/rearside of the radiator housing.
> What you are seeing here are actually two air outlets: The opening for
> the
> radiators is obvious. Directly behind it (towards the camera) is the
> opening
> from the engine bay. Both radiators are in line with each other:
> the oil radiator will only get air that has gone through the water
> radiator.
> I believe that this is a good thing. (The reason that this is
> sometimes done
> differently in the Europa is because of the bad properties of the
> original
> cooling duct).
> On the bottom panel you can see a hinge. Here will be attached an
> adjustable
> cowl flap. In the cruise position, it will be in a direct line with the
> bottom panel of the radiator housing. It will extend considerably
> rearward,
> where the belly slopes down. The outgoing air will be speed up, and
> hopefully smootlly mix with the air passing the radiator housing
> because it
> has the same speed and direction. If more cooling is required, the
> flap will
> move down, making a greater opening, and causing some vacuum behind
> the flap
> to help the air out. Obviously, in maximum cooling position it will
> create
> some drag, although it wouldn't be worse than the factory cowling.
> Note that the sides of the radiator housing will not be visible when
> the
> cowling is finished, as it will overlap the sides of the radiator
> housing.
> (Problem here of course is that the radiator housing is fixed to the
> fuselage, while the bottom cowling needs to be removable. Am not sure
> yet
> where exactly the seam will be made).
>
> Picture 6: Here the shape is better to see. If the cowl flap is in
> place, it
> will be in a direct line with the radiator housing, horizontal with the
> flight direction. Because the belly of the cowling slopes down, the air
> going to the exit will be compressed (read: "speed up") somewhat.
> The complete air path is as follows: There is a small opening in
> front, and
> behind the opening is a diffuser which has "wing-shaped" walls that
> increase
> the area, thus slowing the air down. The slower moving air can pass the
> radiators, and after that the air is speed up again, so when the air is
> released, it has the same direction and speed as the surrounding air.
>
> Of course, al this is theory. Because the cooling properties of the
> factory
> cowling are so bad, I believe that it would actually be difficult to
> make it
> worse. So chances are that my cooling at least gives some better
> cooling and
> aerodynamics.
>
> Note that before I started with the Europa I had no experience at all
> with
> making shapes and working with epoxy. I'm sure that a lot of people
> can do a
> better job than I did, and I'm not really sure how things will look
> after
> applying filler and sanding. I hope it is going to be ok.
>
> Comments are welcome of course!
>
> --
> Frans Veldman
>
>
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