Numerical Simulation of Non-Stationary Heat Transfer Process Related to Thermal Striping Phenomena

摘要

Thermal striping phenomena characterized by stationary random temperature fluctuations are observed in various positions, where two fluids with different temperature are mixed, such as a mixing tee, a combining junction pipe in nuclear power plants, chemical processing plants, etc. Therefore, the structural components located in the positions must be protected against the stationary random thermal process, which might induce high-cycle fatigue. It is noted that, in the thermal striping evaluations, an increase in cost and time to perform conventional experiments cannot be avoided. On the one hand, time-averaged heat transfer coefficients cannot be used in numerical simulations for fluid-structure thermal interactions related to thermal striping phenomena, because the interactions are basically time dependent process. This paper describes a numerical simulation method for thermal striping phenomena and their validations of the evaluation methods for the fluid-structure thermal interaction phenomena based on fundamental water experiments.