Paul=0Ayou know I can't resist temptation! I suspect that a bit of work re
exdhaust extraction might=0Abe profitable, it seems to work well on Long EZ
s, hoping to verify with flight testing in the next month.=0AGraham=0A=0A
=0A=0A________________________________=0A From: Paul McAllister <paul.the.a
viator@gmail.com>=0ATo: europa-list@matronics.com =0ASent: Wednesday, 20 Ju
ne 2012, 17:32=0ASubject: Re: Europa-List: Re: Contact detail & Help=0A =0A
=0AHa ha.... I wondered who was going to be first out of the=0Acloset, me o
r Fran=99s. =C2-Fran=99s and I have=0Abeen collaborating on a
journey of discovery for the last couple of years.=C2- =0AI have been re
luctant to share what I have been doing,=0Amostly because up until now I ha
ve only been able to tell everyone what doesn't=0Awork! Both Fran's and I c
an share funny stories of tuft test showing air flow=0Aout where it should
be flowing in, some take offs where we couldn't get back on=0Athe ground qu
ick enough due overheating and lots of work and re work.=0AFor me, I am sti
ll works in progress, but over the next=0Awinter I plan on a fourth iterati
on over next winter which will be a similar=0Adesign to Fran=99s. If
I can persuade my friend Graham Singleton to come and=0Avisit, it might eve
n a new carbon fiber cowling :)=0A=0A=C2-=0AAt a high level the sources o
f design material we used were:=0A* =C2- =C2- =C2- =C2-Kays & Lo
ndon wedge diffuser=0A* =C2- =C2- =C2- =C2-=C2-Kuchemann & Web
er trumpet diffuser=0A* =C2- =C2- =C2- =C2-=C2-Cooling design
notes from the Central States=0ACanard Group=0A* =C2- =C2- =C2-
=C2-=C2-Taper diffuser design from the Canard group=0A* =C2- =C2
- =C2- =C2-=C2-Oil Streaking presentations from the Central=0AState
s Canard Group=0A* =C2- =C2- =C2- =C2-=C2-Think Vs. think radi
ator notes from Rotary=0AEngine forums.=0A* =C2- =C2- =C2- =C2-
=C2-Cooling Vs flow data from Rotax and Laminova=0A=C2-=0AOur design cr
iteria was:=0ACooling that works in all phases of operation:=0A* =C2-
=C2- =C2- =C2-Ground=0A* =C2- =C2- =C2- =C2-Climb=0A*
=C2- =C2- =C2- =C2-Cruise=0AOperates over a range of -5c to 40c=0AO
ffers the lowest drag possible=0A=C2-=0AThis ultimately dictated a few de
sign solutions:=0A=0ACowl Flap. =0AThis is the only way we could get coolin
g over a large speed=0Arange and ambient temperature.=0A=C2-=0ALaminova l
iquid oil=0Aheat exchanger.=0AIn one of the design iterations that Fran's h
ad created he=0Ahad the oil and water radiators separated. Although this pr
ovided plenty of oil=0Aand liquid cooling it caused a long cycle time to br
ing the oil temperature up=0Ato operating temperature. The Laminova solves
this problem.=C2- One problem that Fran's and I have not been=0Aable to s
olve is the need for a small axillary oil radiator.=0A=C2-=0AThick Vs. Th
in=0ARadiators.=0AI was ultimately able to make the thick radiator work wit
h a=0AKuchemann & Weber trumpet diffuser, but I intend to abandon this. Fro
m our=0Aresearch we have discovered that 70 to 80% of the heat exchange occ
urs in the=0Afirst 20mm of the radiator.=0A=C2-=0ADiffused Inlets.=0AAt f
irst glance Fran's cowl appears to have no diffuser on=0Athe inlet side of
the radiator, however it works very well.=C2- After reading the design no
tes for the Kays=0A& London wedge diffuser our hypothesis is that because t
he coolant radiator=0Ais at an angle to the relative wind it behaves like a
wedge diffusers.=0A=C2-=0AOther thoughts &=0Aobservations.=0AFran
=99s has been flying a working solution for nearly a year=0Aand his design
can be used as is.=C2- I am=0Adoing some experimentation with a single di
ffused inlet that provides the=0Aengine combustion air, inter cooler and th
e engine shroud. =C2-Given the level of effort this has proved to=0Abe I
wouldn=99t recommend anyone copying what I have done, and it remains
to be=0Aseen if it even works.=0AOver next winter I plan on removing the th
ick radiator and I=0Aexpect that this will be a lower drag configuration ov
er what I have.=0APointing the exhaust back is offers a lot of drag reducti
on.=0AI have some photographs that show the exhaust plume on the old style
exhaust=0Ashooting out nearly 2 meters.=C2- For=0Amonowheel the exhaust n
eeds to be much longer so that carbon monoxide does not=0Afind its way into
cabin via the tunnel. Unfortunately this was complex bit of=0Astainless st
eel to fabricate.=0AWhen my cowling is fully open it is the same angle as t
he=0Astandard cowling.=C2- I see 8 knots=0Adifference between fully open
and fully closed.=C2-=0AThis isn't an exact comparison because when my co
wl flap is open air=0Awill spill around the side and I expect this would be
higher drag than the original=0Acowl.=C2- I have done a number of long c
ross=0Acountry trips and for the same manifold pressure settings I am seein
g about 5=0Aknots increase in my cruise.=C2- I have Warp=0Adrive blades a
nd I do not wing root fairings so my set up is not as efficient=0Aas Fran
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