|
|
Andrew,
That exhaust exit is not going to be my
favorite with the fresh air inlet where it is. Be sure you include a CO2
monitor if you fly like that.
You really have a small inlet for your
cooling air. That should hold cooling drag down if you can get it to
work. If you have air flowing thru one heat exchanger and not the
other, you can include a guide vane inside the duct to separate the flow so it
will flow equally or in whatever division you want.
In the first iteration of my cooling
attempts, I had my radiator mounted back at the firewall, leaning backward at
the top so the radiator was about at a 30 degree angle and I ducted the air
from the left nostril back and turned it so that it flowed back to front of the
radiator and then it dumped into the inside of the cowl and exited at the
bottom of the firewall. The oil cooler was a stock 13B cooler which I fed
from the right nostril.
This required the air to make a 360 degree
turn after it entered the cowl….the air apparently didn’t care for
this arrangement and it didn’t cool. :>(
I now have the radiator mounted on the
right side similar to Tracy’s
20b, feeding from the left nostril, and some air from a scoop under the
chin. The oil cooler is under the engine feeding from the chin
scoop. This is pretty draggy, I would say at least 10 knots, but it cools
even on hot days.
If I were to do it again and I have no
current plans to do so. I would put the radiator under the engine, fed
from the chin scoop, the oil cooler on the right side fed form the right
nostril, and install a cowl flap to regulate the air flow for drag improvement.
Bill
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]
Sent: Sunday, June 28, 2015 8:16
PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: West
Aussie Rotary
Ok, resized photo attached, see if this works.
have to wait until I get
back to town for under cowl photo's
Airframe is Australian Lightwing SP4000 (only one in existance I think)
all others are lighter weight versions,
empty 650Kg MTOW 1100kg,B tube frame, non structural glass skin,
aluminium wings, glass control surfaces, even has some wood for floor, so bits
of everything.
210 litres fuel in 4 wing tanks.
2004 Renesis, RD1-c, EC2,EM2. GT electric CS prop.
MGL iefis avionics &
Comms.
Not sure how well this photo will show but air enters under spinner
into divergent duct which turns up into wedge duct at firewall then flows
forward through heat exchangers, oil cooler is out of the 20b Cosmo, air flows
over/around engine to front of cowl and exits in low pressure area with help of
cowl flaps, might work, might not.
Exhaust was a bit of a
dogs breakfast, couldn't exit underneath due to ducting taking up all the
space, cabin fresh air inlet then dictated exhaust exit would be high on cowl,
will suck and see how it goes and keep trimming length of exhaust until soot
builds up on airframe.
I'm skeptical about the
20b Cosmo oil cooler, fin spacing is closer than on radiator so I think it must
add restriction so air might take least course of resistance through radiator.
option may be to get new oil cooler with same core as radiator. oil cooler is
1/3rd size of radiator & they sit side by side across firewall, sharing air
from ducting.
I don't think downstream blockage is the issue. oil cooler air has
clear run along right side of engine,only things in the way is the ignition
coils & 2 stoke oil tank ( to be removed as going for premixing of oil)
would be more of issue for coolant air as that has the block, intake &
exhaust manifolds to negotiate.
putting thermocouples on
is on the list to do.
Good to hear of another
project in the making. Be good if Tracy
decided to sell drawings for his drive if he cant get anyone to take on
manufacture, plenty of places here capable of making them. just 1 off's will
always be more expensive. or is Neil thinking of going into production of his?
I got a 20b for next project which will need a drive also, once I find a
suitable airframe.
On Sun, Jun 28, 2015 at 11:36 PM, Charlie England <flyrotary@lancaironline.net>
wrote
Hi Andrew,B
Good to hear that another rotary is 'close' (to flying). I noticed the
1st line 'without photo'. Did earlier attempts bounce? I think the message
size, including attachments, is around 200KB. Try resizing the image to 150K or
smaller. If you need help resizing, let us know. There's a plugin for Win XP
that makes it very easy; Win7/8 is a bit more convoluted but not that hard. I
for one would love to see as many pics as you have time to send.B
Please help those of us who are memory challenged & let us know
which airframe. Runner length shouldn't be an issue (I hope it isn't; that's
about the length of mine), since Tracy's
Renesis uses intakes about that long.
|
|