title: Steady two-layer flows over an obstacle.
abstract: Nonlinear waves in a forced channel flow of two contiguous homogeneous fluids of different densities are considered. Each fluid layer is of finite depth. The forcing is due to an obstruction lying on the bottom. The study is restricted to steady flows. First a weakly nonlinear analysis is performed. At leading order the problem reduces to a forced Korteweg-de Vries equation, except near a critical value of the ratio of layer depths which leads to the vanishing of the nonlinear term. The weakly nonlinear results obtained by integrating the forced Korteweg-de Vries equation are validated by comparison with numerical results obtained by solving the full governing equations. The numerical method is based on boundary integral equation techniques. Although the problem of two-layer flows over an obstacle is a classical problem, several branches of solutions which have never been computed before are obtained.
authors.affiliation: Centre de Mathématiques et de Leurs Applications, Ecole Normale Supérieure de Cachan, 61 avenue du Président Wilson, 94235 Cachan cedex, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Dias
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Vanden-Broeck
mesh_terms: D003198:Computer Simulation; D008962:Models, Theoretical; D009038:Motion; D017711:Nonlinear Dynamics; D010316:Particle Size; D012212:Rheology / Q000379:methods*; D012680:Sensitivity and Specificity; D012996:Solutions; D014783:Viscosity
chemical_list: D012996:Solutions