Research on flow instability phenomena in multiple loop system

In the storage tanks used for high temperature working fluid and having free surfaces, the variation of liquid level and sloshing exert repeated thermal stress to the vessels, which are in danger of causing fatigue and breakdown. As the causes of the variation of liquid level and sloshing, earthquakes, the vibration due to operation and many others are conceivable. In the case of the plant in which storage tanks have many free liquid surfaces, and are connected with pipings as one closed loop, and working fluid circulates, the variation of liquid level by the interference among free liquid surfaces may occur. Further, in the case of the plant in which multiple loops are formed while one closed loop owns a part jointly with another loop, the interference among the loops may arise. In this research, it is aimed at to examine the stability of free liquid surfaces including sloshing regarding the triple loop system having many liquid surfaces. The experimental setup, the experimental method, data processing, the experimental parameters, and the results of the experiment on the natural frequency of the fluid in pipings and sloshing frequency, the experiment on sloshing wave height in the case of changing sloshing frequency and the experiment on the effect that the bypass in a pump and the pipe connecting tanks exerted to sloshing wave height are reported. (K.I.)