Stokes’ Law
Definition
The relation v = (d squared times (rho_p minus rho_w) times g) divided by (18 times mu) governing settling velocity of spherical particles in still fluid.
Settling velocity scales with the square of particle diameter and with the density difference between particle and water, and inversely with dynamic viscosity. It is a first-order estimate that real systems deviate from due to turbulence, non-spherical particles, and flocculation. Water density is about 998 kg per cubic meter and dynamic viscosity about 0.001 Pa second at 20 degrees C.
Related concepts
Part of The Blueprint of Water · 📏 measurement