Study on fluid mixing phenomena for evalution of thermal striping in a mixing tee

not registered; Tanaka, Masaaki  ; Kimura, Nobuyuki; Kamide, Hideki 

Research of high cycle thermal fatigue is significant for the safety of a fast reactor. In Japan Nuclear Cycle Development Institute, several experiments and the improvement of the analysis methods have been carried out to construct an evaluation rule of high cycle thermal fatigue. In this study, fluid temperature and flow velocity distributions were measured and direct numerical simulation (DNS) code was applied to understand mixing phenomena. From the experimental results, a prominent frequency of temperature fluctuation was observed just down stream from the branch pipe where temperature fluctuation intensity was also large. The velocity measurement showed that the vortices were generated in the wake region behind the branch pipe jet. This vortex was correlated with prominent frequency of the temperature fluctuation. The temperature and velocity field and the two vortices in the wake region were reproduced by DNS.