Cress Help - Flow - Pipe flow - A17.1

Averaged flow with laminar flow

This calculation rule gives some general calculation rules for closed pipelines.

This calculation rule gives some general calculation rules for closed pipelines.

Equations used:

Average flow velocity in laminar flow:

in which:

D: diameter pipeline [m]
H: energy level averaged out over an opening [m]
h: local hydraulic head (pressure in mwk) in pipeline [m]
g: acceleration of gravity (= 9.81) [m/s2]
l: length of the pipeline section under consideration [m]
Q: flow through the pipeline [m3/s]
R: hydraulic radius of the pipeline = 0.25×D [m]
r: radius of the pipeline [m]
vav: average flow velocity [m/s]
ΔHw: energy level (in horizontal pipes equal to the pressure head difference [m]
v: kinematic viscosity (see following table) [m2/s]