flow rate in pipes

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Offline Atomic-S

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flow rate in pipes
« on: 15/07/2007 05:25:35 »
What is the formula for the flow rate (e.g., litres/sec) of a liquid in a pipe of a given length and diameter, having a given pressure difference between the ends?
 

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Offline eric l

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flow rate in pipes
« Reply #1 on: 15/07/2007 08:37:56 »
Poiseulle's formula

D = [(π.r4.d)/8.η].[(p1-p2)/l]

with
  • π = pi (or 3.1416)
  • D = flow rate in kg/sec
  • r = radius of the pipe in m
  • d = density in kg/m3
  • η = dynamic viscosity in Ns/m2
  • (p1- p2) = pressure difference in N/m2
  • l = length in m

You'll find this formula in any advance handbook on physics or engineering.  I copied it from "polytechnisch zakboekje", a Dutch pocketbook with all kinds of physical and chemical constants, formulae and other things useful for engineers.
I'm affraid it will require some converting to more traditional units.
 
"Wonder is no wonder" (Simon Stevin 1548-1620)

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Offline Atomic-S

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flow rate in pipes
« Reply #2 on: 16/07/2007 06:20:25 »
Thanx; I knew it depended steeply upon the diameter, but was not sure just how steeply.