Laboratory Modeling of the Transformation of Linearly Stratified Fluid into Steplike Stratified Fluid under Vertically Uniform Turbulent Stirring

We have performed several series of laboratory experiments to study the mixing of a water layer with an initially constant vertical salinity (density) gradient by horizontally oscillating vertical rods, which exert a uniform turbulent (stirring) effect throughout the entire water layer. This stirring has resulted in the formation of a steplike salinity (density) profile structure in most experiments, which is manifested in a vertical sequence of mixed layers separated by high-gradient salinity (density) interfaces. The steplike structure is not formed in some experiments, and stratification is characterized by a continuous vertical density gradient, decreasing over time. The dependence of the dimensionless initial layer thickness on the initial value of the Richardson number is established, and a diagram of the steplike structure formation boundaries is presented in Richardson–Reynolds number coordinates. The stages of the steplike structure evolution and its breakdown are examined in detail to complete mixing of the water column.