**Fluid Flow Table of Contents**

Hydraulic and Pneumatic Knowledge

Fluid Power Equipment

*Darcys Equation Fluids Flow Equation
- also called Darcy–Weisbach equation. *

In fluid dynamics , the **Darcy–Weisbach equation **is a phenomenological equation, which relates the head loss — or pressure loss — due to friction along a given length of pipe to the average velocity of the fluid flow.

The Darcy–Weisbach equation contains a dimensionless friction factor, known as the **Darcy friction factor **. This is also called the **Darcy–Weisbach friction factor **or **Moody friction factor **. The Darcy friction factor is four times the Fanning friction factor , with which it should not be confused.

The frictional head loss can be calculated
using a mathematical relationship that is known as Darcys
equation for head loss. The equation takes two distinct
forms. The first form of Darcys equation
determines the losses in the system associated with the
length of the pipe.