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At 07:38 PM 10/16/2002 -0400, you wrote:
From
the data, it appears that the Davies EWP can do the same cooling job for
approx 105 watts of energy (7.5 amps x 14 volts = 105 Watts). 6000 watts =
approx 8.5 HP or say a net gain of 6000-105 = 5895 Watts = 7.9 HP.
It appears that the crucial difference is that the assumption was made that
6000 watts constituted the power required to drive the coolant at those rpms
to assure adequate cooling. What the Davies charts seem to imply is that
most of that energy is wasted by a mechanical pump (at that engine rpm) and
is simply unnecessary
friction and head pressure losses.
I know, I know - my skepticism is still showing through and I'm not even
from Missouri {:>). But, I am convinced that previous discussions about the
viability of the EWP may have been based on flawed assumptions and the topic
deserves another look.
So, Todd, based on this technical data, it appears that I may have been off
in
left field on my comments about the practicality of the electric water pump
for aircraft application. However, I will truly be convinced when we get
your data. Looking forward to your results.
Ed Anderson
Ed,
So based on your analysis of the Davies Craig data the EWP is about 57 times as efficient as a typical mechanical pump? Some improvement in efficiency over a belt drive wouldnt surprise me, but 57 times as efficient? That would be a shocking improvement in efficiency. You'd think that the OEM's would be all over that.
I truly hope that Todd's experiment with the EWP works out. If he flies with it and is able to successfully cool his airplane you can count on my order. And unlike some people, I'll be happy to admit I'm wrong. Meanwhile I think I'll maintain a healthy dose of skepticism.
Mike Wills
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