X-Mozilla-Keys:                                                                                 
Al Gietzen wrote:

It would be great to have the pressure, flow, RPM mapping for the coolant
pump; but maybe in the mean time we could get some useful data more easily.

The approximate flow rate of the pump can be backed out pretty easily from a
measurement of the temperature drop around the coolant loop and the fuel
burn.  Maybe a couple of our flying friends already can collect this data
for a range of RPM.  Or maybe they need to add a temporary thermocouple to
the other side of the loop.  Fly at steady speed at the low end of your
useful RPM range for five minutes or so to get things into equilibrium; take
a reading of coolant inlet and outlet temp and fuel flow.  Repeat at four or
five points up to about 6000 RPM.  Maybe do the whole thing twice to see if
it is repeatable.

Of course this is just for one cooling system design, but includes some
variables that garbage-can-to-garbage-can pumping won't.  It would be
interesting to see if anyone achieves something close to the rated 35-38 gpm
(I think).

Make any sense?  Anyone want to do this?  If Paul will remind me how many
Btu we get from a gallon of fuel, I'll do the data reduction.  Oh yes; if
the test plane(s) is not using straight water, we would also need to know
the water/EG ratio.  Is this getting too tough?  Well, can't hurt to ask.

Al Gietzen

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