calculating horsepower consumed across parallel pipe 1

[whotmewory]

I can't remember...

...For purposes of calculating horsepower consumed across parallel pipe paths, when flow is equally distributed across parallel paths of the same size, are the pressure drops across the individual runs additive

I mean...do you find HP based on...

HP = [Qtotal * (SUM Hindividual)] / 3956...

or

HP = SUM (Qpartial * Hindividual) / 3956...?

 

[dcasto]

no, you can use the individual pressure drop times the total flowrate.

Or sum up the flow times pressure drop times constant for each parallel leg.

OH, assuming a liquid.

 

[whotmewory]

Really?

So for - say - I don't know...15 psig across each of three paths with 10 GPM dividing equally - 3.33 GPM per path - then it's 10 GPM x 15 psig - just one of the delat-P values?

PS: can you elaborate on the "constant" you mention?

 

[BigInch]

HPbn = HorsePower each branch = (3.33 gpm) / (7.4805 gal/cf) / (60s/m) * (15 psi * 144 in2/ft2) / (62.4 pcf) / SG * (SG * 62.4 pcf)/ (550 ft-lbs/s)

Total power = HPb1 + HPb2 + ... + HPbn

"If everything seems under control, you're just not moving fast enough."
- Mario Andretti- When asked about transient hydraulics

http://virtualpipeline.spaces.msn.com