Stokes's Law

Physical Law

Stokes's Law is an empirical law for the drag exerted on a spherical body $\BB$ with a small Reynolds number in a viscous fluid $\FF$.

It is formulated as:

$\mathbf F_{\rm d} = 6 \pi \mu r \mathbf v$

where:

$\mathbf F_{\rm d}$ is the Stokes's drag acting on the boundary between $\FF$ and $\BB$ in newtons

$\mu$ is the dynamic viscosity in pascal-seconds

$r$ is the radius of $\BB$ in metres

$\mathbf v$ is the velocity of $\FF$ relative to $\BB$ in metres per second.

Also known as

Stokes's Law can also be rendered as Stokes' Law.

Source of Name

This entry was named for George Gabriel Stokes.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): Stokes, Sir George Gabriel (1819-1903)
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): Stokes, Sir George Gabriel (1819-1903)