Solenoidal vector field

In vector calculus a solenoidal vector field (also known as an incompressible vector field, a divergence-free vector field, or a transverse vector field) is a vector field v with divergence zero at all points in the field: $${\displaystyle \nabla \cdot \mathbf {v} =0.}$$ A common way of expressing this property is to say that the field has no sources or sinks.