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The most complete compendum of P/Q graphs. (BIG)

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All Graphs; ALL.



P/Q, ALL
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Pump Efficiency (pip/pop) [ Greater than 4M head]
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Overall Pump Efficiency (eip/pop) [ALL]
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Point of Best Efficiency, ALL
 
Last edited:
UberBlue said:
whew!? Tell me about it. I spent three full days working on those bad boys.

Well done.
Data manipulation and graph presentation is a thankless chore.
However using Watts~ m(H2O)x lpm/6 did a rough check on a couple of values:-
MCP1200 @ 10 lpm & 8.6m(H2O), W~ 14.3w.
Eheim1048 @ 5lpm & 5.1m(H2O), W~ 0.9w

Arithmetic error?
 
Les56 said:


Well done.
Data manipulation and graph presentation is a thankless chore.
However using Watts~ m(H2O)x lpm/6 did a rough check on a couple of values:-
MCP1200 @ 10 lpm & 8.6m(H2O), W~ 14.3w.
Eheim1048 @ 5lpm & 5.1m(H2O), W~ 0.9w

Arithmetic error?

I dunno. My math skill are quite horrid. I can plug stuff into a formula and that's about it.

I went about things the long way and used the formula-

P = Q*H*s/366

Where:

Q = flow rate in M^3/h
H = total head in meters
s = specific gravity
P = water horsepower

Then it was a simple matter of converting wHP to watts. 1 wHP = 746.043 watts.

(0.6m^3*8.58Mh*1)/366 = 0.014065574wHP = 10.49352285watts

Thank god for Excel.

Since you're the math guru, want the source data?

EDIT: This just dawned on me. The water block resistance curves and the pump P/Q's intersect at the same flow rates on both types of charts. If the PBE data was bad, that wouldn't be the case.
 
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UberBlue said:
......
Since you're the math guru, .............................?
...
I am not a "math guru".
I just do sums on beer-mats with the aid of a calculator(misplaced slide rule).
However I suspect the equation is wrong:

My "beer-mat" version:-
Power(foot pounds/sec) = Head(ft) x Flow(lb/sec) =Head(3.281m) x Flow(8.33 gps) =Head(3.281m) x Flow(8.33 x 0.0734 m^3/h)
= 2.006 x Head(mH2O) x Flow(m^3/h)
Power(Horsepower) = 2.006/550 x Head(mH2O) x Flow(m^3/h) = 0.00365 x Head(mH2O) x Flow(m^3/h)
 
Les56 said:

I am not a "math guru".
I just do sums on beer-mats with the aid of a calculator(misplaced slide rule).
However I suspect the equation is wrong:

My "beer-mat" version:-
Power(foot pounds/sec) = Head(ft) x Flow(lb/sec) =Head(3.281m) x Flow(8.33 gps) =Head(3.281m) x Flow(8.33 x 0.0734 m^3/h)
= 2.006 x Head(mH2O) x Flow(m^3/h)
Power(Horsepower) = 2.006/550 x Head(mH2O) x Flow(m^3/h) = 0.00365 x Head(mH2O) x Flow(m^3/h)

Ahhh! My brain, it's tingling.

And you're being modest. I've seen some of the work you've done @ procooling.

The equation I used is a pump industry standard. A couple of people "who are in the know" about pumps checked my preliminary math and verified it correct.

There are two versions of the equation I used, one for metric units and one for US units. And there is a slight difference between water horsepower and brake horsepower.

Like I said, about the extent of my math ability is plugging numbers into an equation. I can find the equation I need and interpret the output of it, but as to what the equation is actually doing, it's usually beyond me. Like the "366" in my equation. I have no idea what that is. I just know I have to divide by it.
 
Thanks for the kind words.

They're going to get better. I hopefully belive I have a crap load of radiator and waterblock data to soon put on there.
 
Now what would be nice would be an interactive calculator and grapher.

Select the waterblock from a drop-down menu
Select the pump from a drop-down menu
Select the radiator from a drop-down menu
Select the fan(s) from a drop-down menu
Assume 2m of 1/2" tubing
Type in a heat-load

A whole mass of values and PQ curves comes out.

Of course this requires engineering level data for the devices in question.
 
i can do that in C++ but of course it would be in a dos console.
actually made a very similar program that does the same thing but with machine productions for numbers in my 'programming for engineers' class, hehe. give me the tables and you'll get a program.
 
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