Abstract
The present paper describes the results of numerical and experimental studies of the flow pattern and the displacement efficiency of old water in a cylindrical water supply tank. In the present study a three-dimensional turbulent flow calculation was carried out using FLUENT to solve the flow in the tank. The calculated results for flow patterns and the mean residual concentration of old water were compared with the experimental results and showed good quantitative agreement. The displacement efficiency of old water in the tank having an inlet pipe with a diverging nozzle and an outlet pipe with a circular baffle plate is better than those of the other tanks. The decrease in the displacement efficiency of old water in a tank that has inlet and outlet pipes the center of the tank without a diverging nozzle and a baffle plate is related to the large fluctuation and the recirculation of flow in the tank.
