Hydraulic Diameter

on 19 February 2018. Posted in Fluid Dynamics

Hydraulic diameter, abbreviated as \(d_h\), is normally used when the flow is in non-circular pipe or tubes and channels. Circular pipe has the same pressure drop of a rectangular channel but a greater average velocity. Square or rectangular pipes have a greater weight and a greater pressure drop compared with a circular pipe with the same section. For established shapes, various calculations are linked below.

hydraulic diameter formula
\(\large{ d_h = \frac { 4 \; A_c } { P } }\)
Units	English	Metric
\(\large{ d_h }\) = hydraulic diameter	\(\large{ ft }\)	\(\large{ m }\)
\(\large{ A_c }\) = area cross-section of flow	\(\large{ ft^2 }\)	\(\large{ m^2 }\)
\(\large{ P }\) = wetting perimeter cross-section	\(\large{ ft }\)	\(\large{ m }\)