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Message
Greetings,
I've only been skimming
through the cooling posts, but I haven't seen much talk of electric fans.
I was thinking about this during my drive time yesterday, and it seems to me
that we have exactly the same need for an electric fan as a car does.
- Packaging limits size and
location of radiators.
- Ducting optimized
for normal cruise speed, fan compensates at low
speeds.
It would seem to me
that the best situation would be to optimized your inlet and
ducting for normal cruise flight, then use a fan during
climb. The
drawbacks would be weight, drag, and perhaps bearing life on the fan, but the
positives could make up for these I think.
From what I've read, it's
common to use a switch to tie the motor leads together, which keeps the
motor from completely freewheeling when unpowered
in cruise. It would seem that you can reduce the drag and
bearing problems that way. I would also think a clever guy could provide a
switch mode that allows you to generate alternate electricity from the
freewheeling fan.
Just something old to
think about again.
Rusty
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