Characteristic of Natural Circulation Temperature Fluctuation Under Rolling Motion Condition

The characteristics of natural circulation temperature fluctuation are studied experimentally and theoretically. Experimental results show that rolling motion may cause the coolant fluctuation which results in the periodical oscillation of wall and fluid temperatures. The amplitude of wall temperature fluctuation is larger than that of fluid temperature oscillation, and amplitude of wall temperature fluctuation increases with rolling period and amplitude increasing. Because of the wall heat capacity, there is a phase difference between the fluctuation curves of fluid and outlet fluid temperatures. A mathematical model is also conducted to simulate the temperature fluctuation under coolant flow fluctuation condition. The theoretical results agree well with experimental data.