Free-Surface Flows Due to a Submerged Cylinder in a Uniform Current

Abstract

A s ubmerged cylinder in a uniform stream fl ow is approximated by a horizontal doublet, following Lamb’s classical method. Surface tension eff ects and a dipole are included in a f ully nonlinear, unsteady, non-periodic, boundary-integral solver. Nonlinear effects are modelled by considering a fl at free s urface or a linear stationary s olution as an i nitial condition f or the f ully nonlinear irrotational fl ow program. L ong run computations show that these unsteady fl ows approach a steady solution f or some parameters after waves have r adiated away. I n other cases the fl ow does not approach a steady solution. Interesting f eatures at the free s urface are f ound such as the appearance of “parasitic capillaries” near the crest of gravity waves and the f ormation of capillary-gravity waves upstream the cylinder.