Stokes flow (named after
George Gabriel Stokes), also named
creeping flow or
creeping motion, is a type of
fluid flow where
advective inertial forces are small compared with
viscous forces. The
Reynolds number is low, i.e.
. This is a typical situation in flows where the fluid velocities are very slow, the viscosities are very large, or the length-scales of the flow are very small. Creeping flow was first studied to understand
lubrication. In nature this type of flow occurs in the swimming of
microorganisms and
sperm and the flow of
lava. In technology, it occurs in
paint,
MEMS devices, and in the flow of viscous
polymers generally.