Interface Geometry for Two-Layered Stratified Flow

Several flow situations exist involving density difference in which vertical density gradients are much larger than those in the horizontal direction. In the analysis of such flows, a common approach schematizes the flow as two distinct homogeneous layers. For example, in the case of an arrested wedge of warm water overlying cooler water in the vicinity of a power plant outlet, the interface is generally defined such that the vertically averaged velocity in the warm upper layer is zero, unless recirculation is occurring. For recirculation of cooling water, the discharges in both layers are nonzero. There are numerous other situations in which discharges in both layers are nonzero; e.g., thermally driven exchange flows, exchange flows as a result of differences in salt concentration, and buoyancy driven side-arm circulations to name a few.