Abstract:
There are mainly two excitation mechanisms in the vibration of the thermo-well at the main pipe of reactor coolant loop under cross flow: turbulence and vortex shedding. The natural frequencies of the G1″and G1″ 1/4 thermo-well and the vortex shedding frequencies are calculated, respectively, in this paper. The vortex shedding lock-in is analyzed for two different thermo-wells, and then the flow induced vibration fatigue of the thermo-well is studied using a simplified engineering approach.