# Resistance Coefficient

Resistance coefficient, abbreviated as K, a dimensionless number, is how much resistance to the flow an obstacle has. This is the opposite of flow coefficient which is how much flow capacity an obstacle allows.

## Resistance Coefficient formula

\(\large{ K = f_d \; \frac {l} {d} }\) |

### Where:

\(\large{ K }\) = resistance coefficient

\(\large{ f_d }\) = Darcy friction factor

\(\large{ d }\) = inside diameter of pipe

\(\large{ l }\) = lenght of pipe

\(\large{ \frac{l}{d} }\) = equivalent length of the obstruction (dimensionless)

Tags: Equations for Coefficient Equations for Orifice and Nozzle