Subject: [FlyRotary] Re: Electric Water Pumps and Heat Rejection


> Ed, et.al.
> Last year I made measurements on the Mazda Water pump installed on the
> block, pumping the water through the block. I have a 225K PDF file
> describing the tests. if someone wants a personal copy, email me and I
will
> send it out.
>
> Key points: I drove the pump at 2500 to 5500 rpm, by varying pulley size.
I
> drove the pump with a 1.5 horsepower saw motor, and had no difficulty
using
> only one belt. However, when I tried an 8 inch drive pulley supplied by
Paul
> Lamar to go higher in pump rpm, the motor would blow my circuit-breaker.
So
> the power goes up dramatically as the rpm goes up, but at reasonable rpm,
> the power is within the capability of the 1.5horse motor.
> Bill Schertz

Just one additional comment on this subject.   The power required (for a
centrifugal pump) varies with rpm and head pressure (which determines
volume).  But here is the point - Volume is the key parameter.  If you
restrict volume with higher head pressure,  power required goes DOWN, not
up.  Most everyone here has heard the effect when you restrict the flow
through a vacuum cleaner (a centrifugal pump).   This has several
implications in an aircraft application.

Tracy Crook