Hydraulics and mixing in controlled exchange flows

Numerical simulations of bidirectional density-driven exchange flows are us ed to study the effects of turbulent mixing in these flows. The numerical e xperiments are designed so that it is possible to specify the intensity of mixing, which allows the investigation of a wide range of hows that are dif ficult to model in the laboratory The simulated flows are compared to two a nalytical solutions, first, the two-layer hydraulic solution which has no m ixing, and second, a solution in which turbulent mixing dominates the flow. We are able to model exchange flows similar to either of these limits by m odifying the turbulent mixing, as well as simulating behavior between these two extremes. The simulations demonstrate that the two analytical solution s form the limits of a wide class of problems and that the flow regime in b etween the limiting solutions can be described by a single nondimensional p arameter Gr(T)A(2).