  Motivated by DNA electrophoresis near a nanopore, we consider the flow field
around an "elongated jet", a long thin source which injects momentum into a
liquid. This solution qualitatively describes the electro-osmotic flow around a
long rigid polymer, where due to electrohydrodynamic coupling, the solvent
receives momentum from the electric field. Based on the qualitative behavior of
the elongated jet solution, we develop a coarse-grained scheme which reproduces
the known theoretical results regarding the electrophoretic behavior of a long
rigid polymer and a polymer coil in a uniform field, which we then exploit to
analyze the electrophoresis of a polymer coil in the non-uniform field near a
nanopore.
