# Solenoidal field

tubular field

A vector field in having neither sources nor sinks, i.e. its divergence vanishes at all its points. The flow of a solenoidal field through any closed piecewise-smooth oriented boundary of any domain is equal to zero. Solenoidal fields are characterized by their so-called vector potential, that is, a vector field such that . Examples of solenoidal fields are field of velocities of an incompressible liquid and the magnetic field within an infinite solenoid.