The stream function is defined for two-dimensional flows of various kinds.

For periodic two-dimensional flows, stretching fields have been shown to be closely related to the mixing of a passive scalar concentration field.

This correction factor is correct only for two-dimensional flow.

A cylinder (or disk) of radius is placed in two-dimensional, incompressible, inviscid flow.

In two-dimensional flow these profiles remain constant at all blade heights.

The total stress (we are still considering a two-dimensional flow for which the boundary layer equations apply).

The mean velocity also varies vertically, and we shall confine attention to two-dimensional flow.

For a two-dimensional flow, the divergence of has only two terms and quantifies the change in area rather than volume.

When the forces associated with two-dimensional, incompressible, irrotational, inviscid steady flow across a body are calculated, there is no drag.

For a two-dimensional flow the vorticity acts as a measure of the local rotation of fluid elements.