抄録
Thermal fatigue of pipelines in nuclear power plants is caused by thermal stress due to temperature fluctuation. The cavity flow is one of typical flow patterns which cause the high-cycle thermal fatigue. It occurs in a branch pipe under the condition that the end of the branch pipe is closed by a valve and so on and the other edge is connected to main pipe. In order to evaluate a number of different piping systems on plants, establishing evaluation methods based on numerical simulation has been expected. In this study, analyses were conducted under the condition that main flow velocity is less than 5m/s with the aim of confirming the effects of main pipe velocity under isothermal condition.
