Numerical Simulation on Flow Induced Vibration and Fretting Wear of a Steam Generator

The steam generator (SG) is a key component in the PWR nuclear power plant. U-shaped tube bundles are subjected to cross flow in inlet and bend sections. According to the design standards of steam generators, short-term flow induced vibration (FIV) damage could be avoided, but wear and corrosion of tubes still exists. Both fluid and structure parameters are needed in FIV analysis. As direct modeling of SG flow field is almost infeasible, the porous medium model has been widely used instead. Using porous medium model can only obtain the gap velocity approximately by mathematical methods with many other unclear parameters. A combination method of direct modeling and porous medium model was established in this research. The direct modeling section could give the details of fluid forces and the accurate gap velocity. Using the fluid forces, explicit dynamic analyses of tube with supports were carried out to get FIV response and contact forces. In this paper, a typical SG model was studied in designed experimental conditions, and the results were compared with published literatures. The results demonstrate that the numerical simulation along with the combination model and explicit dynamic analysis can provide new methods into the flow-induced vibration and fretting wear of multi-span U-tubes which can be applied into future design for steam generators and other heat exchangers with large size.