X-Mozilla-Keys:                                                                                 
marc mularz wrote:

I have been thinking about this idea for a couple of weeks and now that the
subject of RC model ducted fans has surfaced I thought that I'd throw it out
for some possible discussion.  Some of the electrical ducted fans used for
RC models seem to be capable of moving a substantial amount of air while
using only a small amount of electrical energy.  Being a releative "newbie"
to this newsletter, I'm not sure of the cooling needs of a rotary engine at
idle. However, it would seem to me that with a properly designed exit
portion of a radiator diffuser, a small ducted fan could be incorporated to
provide ground cooling of the radiator during taxi.  The ducted fan portion
could be closed off prior to takeoff to prevent damage to the unit from the
much higher airflow through the rad during flight operations and would seem
to be a way to have a less "draggy" fan available for use for ground cooling
as opposed to those big round fans used in auto rad applications. (And if
you really needed that extra 0.2 kt of airspeed, you could even operate the
unit in flight :) )
Just a thought.
Marc M

Not a bad idea.

The big proplem Marc is; how do you take the air from a three inch
diameter fan
and distribute it over a 20 by 20 inch radiator?. If you put it in
the intake opening it will really zing along and partially  block the
normal
flow. Maybe you could have a separate small duct with a butterfly valve
to isolate the fan at high speeds when you did not need it for cooling.

Paul Lamar
 
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