1992 Volume 6 Issue 2 Pages 132-148
Research work concerning vertical mixing processes in stratified water areas is briefly reviewed. Attention is focused on vertical mixing phenomena which are found in the hydraulic engineering field, such as estuaries, lakes, reservoirs, land locked bays, etc. From the view point of the mixing mechanism, entrainment processes are classified into three categories, i.e., (1) shear induced entrainment (Stype), (2) entrainment due to eddy convection and diffusion in the mechanical stirring fied (DM-type) and (3) entrainment due to thermal convection (DT-type). The turbulence structure and entrainment mechanism for each case are examined and discussed. Experimental and analytical work on entrainment relationships is shown for several types of stratified flow fields among which shear-free turbulence generated by an oscillating grid, stratified shear flows, wind-induced mixing and turbulent penetrative convection are included.
