전산유체역학 기술을 활용한 주증기 배관 유체유발 진동 평가

Flow-induced vibrations in piping system lead to premature wear and failure of the system and equipment. If a vortex shedding frequency owing to the dead-end pipe branch is overlapped with a pipe natural frequency, the magnitude of the amplitude increases, resulting in a fatigue failure. In particular, the steam used in the nuclear power plant flows fast under a high temperature and pressure, causing serious damage in the system and equipment if flow-induced vibrations are delivered to the steam generator. This study performed computational fluid dynamics (CFD) simulations to predict the vortex shedding frequencies of the main steam atmosphere dump valve (MSADV) and main steam safety valve (MSSV) in the main steam line of nuclear power plants. The CFD-based evaluation method was validated by comparing the actual quantities of the vibrations in the pipe at 100% power operation of the nuclear power plant.