Displacement Efficiency of Water in a Cylindrical Tank

Abstract

The objective of the present study is to improve the design of a cylindrical water supply tank in order to achieve better displacement efficiency of old water in a cylindrical water supply tank. The present paper describes the results of experimental and numerical studies of the flow pattern and the displacement efficiency of old water in a cylindrical water supply tank. 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 that of the other considered tank designs. The decrease in the displacement efficiency of old water in a tank that has the inlet and the outlet pipes at 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. In addition, the results of the numerical simulation by FLUENT 6.3 for flow patterns and the mean residual concentration of old water in a cylindrical water supply tank were in good agreement with the experimental results.