Interfacial mixing of the stratified flow in the trapezoidal-shape channel with presence of background vorticity

The dynamics of gravity current developing along a channel with a trapezoidal-shape cross-section is numerically investigated using the computational fluid dynamics modelling approach. The numerical modelling results are qualitatively compared with the observed stratified-flow dynamics characteristics, gained from a series of large-scale experiments of the uni- and bi-directional flows across a submerged, trapezoidal, sill obstruction with presence of background vorticity. Measured velocity and density profiles are used at the channel cross-sections to observe internal-flow dynamics under a range of parametric forcing conditions, related to fluid properties, fluxes and sill conditions. The computational domain of the numerical study is a scaled version of the trapezoidal stratified-flow flume used for the experimental study (Adduce et al., 2019).