Numerical investigation on the effect of different factors on the flow-induced vibration of wire-wrapped fuel rod under axial flow

Fixing fuel rods with wires is a common positioning method in reactors, especially fast reactor cores. Due to the presence of wires, unbalanced or even fluctuating excitation forces are generated when the fluid flows through the fuel rods, resulting in fuel rod vibration. In this paper, the effects of different wire pitches, different inlet velocities and different fuel rod fixation methods on wire-wrapped fuel rod vibration are analyzed using the FSI numerical method. The results show that changing the wire pitch, inlet velocity and fuel rod fixation method can change the magnitude and fluctuation of the fluid pressure on the surface of the fuel rod, which can further change the results of the vibration response of the fuel rod. However, changing any of these factors does not cause the fuel rod to resonate.