# Characteristic Length

Written by Jerry Ratzlaff on . Posted in Classical Mechanics

Characteristic length ( $$l$$ ) is the scale of a physical system.  The length is used in 2D and 3D systems for Fluid Dynamics and Thermodynamics defining the parameter of the system.

Examples of:

### Characteristic Length Formula

$$\large{ l = \frac{ V } { A } }$$

Where:

$$\large{ A }$$ = surface area of the body

$$\large{ l }$$ = characteristic length

$$\large{ V }$$ = volume of the body