Drag coefficient

The Drag and the Drag coefficient $C_D$ is defined as follows:

$C_D=\frac{F_D/A}{\rho v^2/2}$

(1)

where

• $F_D$ is the drag force,
• $\rho$ is the density of the fluid
• $v$ is the speed of the object relative to the fluid,
• $A$ is the cross sectional area.