  The problem of vortex pair motion in two-dimensional plane radial flow is
solved. Under certain conditions for flow parameters, the vortex pair can
reverse its motion within a bounded region. The vortex-pair translational
velocity decreases or increases after passing through the source/sink region,
depending on whether the flow is diverging or converging, respectively. The
rotational motion of two corotating vortexes in a quiescent environment
transforms into motion along a logarithmic spiral in the presence of radial
flow. The problem may have applications in astrophysics and geophysics.
