A special case of the Navier-Stokes Equation can be used to determine the frictional force (called the drag force) arising from the viscosity of a fluid on a spherical body.

Definition

Formula

Drag force on a spherical body in a Fluid

Terms
  • = Drag force onto a spherical body. Being a frictional force, it opposes the direction of velocity, i.e. (in )
  • = Coefficient of Viscosity of the fluid (in )
  • = Radius of spherical body (in )
  • = Velocity (in )

Implications

Can be solved for :

#todo full derivation!