Numerical Investigation on Thermal Striping Conditions for a Tee Junction of LMFBRE Coolant Pipes (VII)

Tanaka, Masaaki  ; Murakami, Satoshi*; Muramatsu, Toshiharu

It is important to evaluate thermal-striping phenomena, which the thermal-fatigue inside the structure material is generated by the temperature fluctuation due to the fluid mixing with different temperature. Especially, the high amplitude and the high number of repetitions of the temperature fluctuation are needed to take into consideration. Moreover, it is necessary to consider the comparatively low frequency components of fluid temperature fluctuation, since the influence to structure material is large. Therefore, it is required to know the generating mechanism and conditions of the high amplitude and the low frequency component of fluid temperature fluctuation. In Japan Nuclear Cycle Development Institute, basic research on the promote system for fluid mixing is conducted, which system ("Turbulence promoter") is expected to reduce the large amplitude and low frequency components of fluid temperature fluctuation in T-junction pipe. In this investigation, it is aimed to validate the effect and to generalize the mixing characteristics of "Turbulence promoter" on the fluid mixing in T-junction pipe, and to contribute the knowledge to the rational design of LMFBR. In this report, numerical simulation for the existing experiment was conducted using a quasi-direct simulation code (DINUS-3).