Study on Temperature Fluctuation Characteristics for High Cycle Thermal Fatigue in a Mixing Tee

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

Research of thermal striping phenomenon is significant for the safety of a fast reactor. In this study, a water experiment for thermal hydraulics in T junction was performed to investigate thermal striping phenomena. Measurement of flow velocity using particle image velocimetry and detailed temperature measurement using a movable thermocouple tree were carried out to clarify mixing phenomena in T junction. The velocity measurement showed that, in the wall jet case, the vortices were generated in the wake region behind the branch pipe jet. This vortex was correlated with prominent frequency of the temperature fluctuation. As a method of evaluating the frequency characteristic of temperature fluctuation, normalized power spectrum density (PSD) was proposed.