Bill.
I am really good at reading someone else’s
graphs…Ha! :>)
So does this show that at 5594 rpm, and 6
lbs pressure, when you would expect 38 GPM, you actually got 24 GPM? You are
very close to the curve for 3730 FPM. Is that what you were running
during your test?
Or, as would be expected, am I misreading
your graphs? :>)
Bill B
From: Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Bill Schertz
Sent: Thursday, May 13, 2010 10:39
AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re:
alternative water pump
Back in 2002 I measured the flow from a 13-B pump, attached
to the engine but driven with an electric motor. The curve is attached. I ran
the pump at 3 different RPM, established by changing the pulley size on the
motor. At 5594 rpm, the pump produced 19 psi at zero flow, and 44 gpm at 0 psi.
At lower RPM, the pump of course pumps less.
The other test I did was to measure the flow through one
core of the two I was using for my installation. That is the curve going up to
the right with the red dots as the experimental points. Since I am running my
cores in parallel, the right hand rising curve is a 'calculated' flow response
for the parallel cores.
Finally, I hooked up the cores to the system, and pumped
water through them. The single large point represents where the flow and
pressure came out, very close to the calculated expected response.
All flow measurements were done by the "bucket and
stop-watch" technique, with multiple runs to get the flow.
Bill Schertz
KIS Cruiser #4045
N343BS
Phase I testing
Sent:
Wednesday, May 12, 2010 11:54 AM
Subject:
[FlyRotary] Re: alternative water pump
Al,
Are you sure of the 40
GPM? That seems like a lot. My radiator in/out is 1.25 inches, so
the water would be traveling at 628 feet per minute at that flow rate.
That is over 7 miles per hour!
Bill B
When
my 20B (with a 13B pump that Atkins referred to as ‘high flow’) was
on the dyno the measured flow was 48 gpm with the standard pulleys. I
expect the dyno cooling loop was fairly low pressure drop compared to our typical
systems, so I’m just guessing 40 gpm is in the ballpark. 628 fpm
(10.5 ft/sec) would not be considered very high - - above 15 ft/sec I’d
consider high.
Al