The data certainly suggests that there is something very amiss with your
test set up.
Why? How much data have you seen on CLOSED LOOP systems?
What goes out the pump goes in the pump. What goes around comes
around.
You do not seem to be developing anything like the pressure that one
would
expect for the rpm. Bill's data seems much more as one would expect.
Bill's data was taken by an OPEN LOOP SYSTEM!!!!!!!!!!!!!!!!!!!!!!
Any pressure on the outlet side is not reflected on the inlet side.
If you want to characterize the pump performance, the attached figure
shows about a minimum complexity setup. Also if you want to measure
the flow resistance of the block or radiator just put it in the circuit
in
place
of the valve. The reservoir will minimize heating with the increased
thermal
mass, and the system will be self priming .
Also the amount and pressure of water flow that we are dealing with is
not all that power hungry. the attached curve shows the theoretical
pumping power required at 60 gpm and 20 psid is less tha 3/4 hp
50 percent efficiency should be possible with a good pump
Vance
The figure you spoke of was missing. In its place was a prop thrust curve.
Here is the second jpg you sent which seems relevant.
Much of the heat is due to the inefficiency of the belt drive
I am sure. Side loads on bearings etc. etc.
If you are not doing anything on Wednesday come on over to the
hangar and witness the test.
Paul Lamar
Closed loop - open loop - the pump should put out useful pressure, and
you seemed to be developing only heat - which is one of the reasons why
that sort of loop
is not generally used for characterizing pump performance. The picture
loss\was
apparently" mouse miss" and hopefully this will be the right one/ Vance
The pump is also doing what it is supposed to be doing. 75 gallons
per minute is 75 gallons per minute!!!!!!!!!!!!!!
I am surprised at you Vance. I am sure you damn well know as well as I damn well know
that that tank will NOT provide any more pressure to the pump
or work any better than a 1.5 inch pipe of the same height
Open loop or closed loop. Did you get a C in hydraulics 101? :)
Looks impressive as hell to the naive laymen of course.
I'll tell you what. You build it and I will hook it to my system and test
it.
Paul Lamar
That's the one, Vance. It will do the job.
In my Physics 101, they taught that it took two items to develop a
pressure-something to push against, and something to push with. Paul's
system runs out of something to push with.
Bob Darrah
What about the soda straw test Bob?
That's it Bob. You get an A obfuscation or spin as they call it now-a-days :)
What the hell does pressure per se have to do with it???? We are looking
for flow through a closed system not pressure. We don't need to "characterize
pump performance" per se as Vance puts it by pumping water out of a well in
an open loop system. We need to find out how many gallons per minute it will
pump through the block and the radiator in a closed loop system.
The pump works as advertised.
Here my data again.
I then pressurize the system to 15 psi using the air compressor.
GPM
Flow Press psi Valve
0 18_17_6 closed
25 18_16_6
35 17_15_6
45 15_13_6
55 15_13_6
65 15_13_6
75 15_13_6
off scale 15_13_6 wide open.
Stoped: 14_14_14 psi. wide open.
Pressures are in order: pump outlet, after flow meter,
inlet side of the pump.
The next message I see on this subject questioning my data and test methods
better have real data on real hardware on a CLOSED LOOP system just
like a real Mazda engine using a real Mazda rotary water pump. It is easy to
talk the talk but you better be able to walk the walk.
Paul Lamar
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