In this project, the P.I. will carry out laboratory experiments and numerical studies of unsteady two-layer strait and sill flow. Analysis of such flows typically uses steady or quasi-steady two- layer hydraulic theory, the validity of which has not been adequately tested for time-dependent flows, such as barotropic tidal forcing. The first approach to this problem will be a laboratory experiment on the effect of unsteady barotropic forcing on the classic lock-exchange problem, focusing on issues of control establishment and maximal exchange. The second approach will be a numerical study of the generation of long nonlinear- dispersive waves by time dependent transcritical forcing.
