HYDRAULIC MODEL TEST AND NUMERICAL SIMULATION OF DENSITY CURRENT

摘要

The behaviours of density current were visualised in a simple cylindrical tank and a hydraulic model shaped as Ariake Bay, set in a rotating tank. In both, water was stratified by dissolving salt in the lower layer. In the cylindrical tank, the spread of density current was well parameterised by newly proposed dimenstonless numbers. When the Rossby number decreases, we observed mat the current was divided into two parts. This may be interpreted as baroclinic instability. In Japan, recently, mere is a big discussion on the effect of Isahaya Dyke on the marine ecosystems in Ariake-Bay. We conducted a hydraulic model test and saw the flow difference between the cases with and without the dyke. Also measured was the effect of artificial density current We found a suitable location forme apparatus for having nutrient-rich water stay at the seaweed cultivation field before it is diffused very much. In addition, we conducted numerical simulations of the above case.