THERMOCLINE LOCATIONS AND BUOYANCY EFFECTS OF STRATIFICATION

This is a follow-up to an earlier experimental investigation of the fl ow fields of the jets induced by a low energy axial flow propeller pum p in a stratified medium in which it was shown that in a stratified me dium with Delta rho / rho(o) greater than or equal to 0.01, jets which start closer to the thermocline achieve less rather than more penetra tion at the same velocity and densimetric Froude number as a result of buoyancy effects of stratification. These buoyancy forces disperse th e jet plumes and consequently reduce penetration. This study shows tha t at thermocline locations beyond 1.75D relative to the position of th e impellers, the buoyancy effects, are negligible. At the transition p oint, one half of the square of the densimetric Froude number is unity indicating that U-o(2) = 2g Delta rho / rho(o)h(so). The study also r einforces the fact that buoyancy effects increase with the width of th e hypolimnion relative to the thermocline width.