A 1% Error in Diameter Is a 4% Error in Flow Rate — Half a Cell of Wall and Poiseuille's Constant
·7 min read
Pipe flow rate rides on the fourth power of the diameter. The same exponent explains a mesh with the wall half a cell off and Poiseuille's 1838 glass tubes.
How Far Must Water Flow Before It Becomes a Parabola — Entrance Length and Hagen–Poiseuille
·4 min read
The pipe entrance region, the Hagen–Poiseuille parabola, and the 64/Re friction factor