Not familiar with the
Chisel or tapered description, George. I may know it as a “wedge”
type? If the Wedge type, all I can tell you is I did quite a
bit of searching trying to find some technical data on it. The only
thing I found was wedge shapes used in supersonic diffusers to slow air down
through use of shock waves (created by supersonic airflow) for inlet to jet
engines. I never found anything on it regarding sub-sonic flow or
for heat exchangers. Anything that will slow air down, increase the
pressure before the core and not cause a lot of eddies and turbulence will
probably cool. But, can’t really comment on how effective they may be
compared to say the “StreamLine duct”.
Yes, the streamline
duct is generally a bit too long for the size cores we use and our cowl
lengths – if you implement a full streamline duct. That is why I have a
small section in my paper on why a truncated streamline duct might still
offer some decent pressure recovery. Since the streamline duct bell
shape is not (or should not be) larger than your core that end should not pose
a problem, unless, of course, you have your radiator canted/inclined and
even then K&W addresses that as
well, although my paper does not.
Ed
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of George Lendich
Sent: Sunday, July 19, 2009 9:41
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: K&W Stream Duct
Explanation
Because of insufficient room
under cowl, many are using the chisel or tapered (my name for it) shaped
chamber rather than the bell shaped. To me, it looks to be, like one side
of the bell shaped chamber, or like squeezing a bell shape down to one
side. Have you studied this approach and do you think it's
comparable.
Hi
Gang
I came across a abstraction
of K&W’s theory of the
Streamline duct that I put together a number of year ago. While it is
my interpretation and therefore subject to error, I have not found anything
in the intervening years that indicates a misunderstanding. While it
is not exactly light reading, I think it is easier to follow than
K&W.
In any case, I thought I would
make it available to promote understanding and discussion {:>)) of one
approach to cooling our installations.
This paper targets four topic
areas:
- Diffusers In
General
- StreamLine
Duct
- Importance of
Inlet to Core area ( Ai/AB
ratio)
- Truncation of
StreamLine Duct
Best
Regards
Ed
Ed
Anderson
Rv-6A N494BW Rotary
Powered
Matthews,
NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
__________ Information from ESET NOD32
Antivirus, version of virus signature database 3267 (20080714)
__________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
--
Homepage:
http://www.flyrotary.com/
Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html
__________ Information from ESET NOD32
Antivirus, version of virus signature database 3267 (20080714)
__________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com