The pressure drop in circular pipes is calculated using
DarcyWeisbach equation:
The flow is considered laminar when Re<2300. In a laminar
flow the friction factor f is calculated by f=64/Re. For
Re>2300 the flow is considered turbulent and the friction factor
is calculated using the Colebrook interpolation function:
This curve fit equation perfectly describes the curves in
the Moody Diagram. In
literature
two definitions of the friction factor are found. The SI based
and Imperial based friction factor which
is exactly four times larger (this
calculator).
