Effects of Turbulence Promoter on Flow Characteristics in T-junction Piping Systems

Recently in nuclear plants, it has occurred thermal fatigue failure accidents because of thermal fluctuations that called Thermal Striping in T-junction where mixed a higher temperature sodium and a colder temperature sodium into each other. Then, we set up turbulence promoter in T-junction piping system, effects of turbulence promoter on flow characteristics have been investigated experimentally using flow visualization techniques (the dye injection method) and velocity measurement by LDV. As a result, it is clarified that secondary streams in pipe sections becomes stronger and diffusion of momentum is promoted in case with turbulent promoter.