Numerical Study on a Single Square Cylinder Subjected to Vortex-Induced Vibration in HTR-PM

The heat transfer tube bundles of the steam generator in high temperature reactor pebble bed module (HTR-PM) are subjected to high speed helium flow, which might lead to vortex-induced vibration (VIV). In the present paper, to investigate the vibration of square cylinder under flow effect, vortex shedding phenomena of a stationary square cylinder at a high Reynolds number equal to 6.8 × 10⁴ is simulated by detached eddy simulation (DES) turbulence models. A comparatively close agreement with previous experimental results is achieved. Combining computational fluid dynamics (CFD) and computational structural dynamics (CSD) methods, a fluid-structure-interaction (FSI) model for VIV of the square cylinder is then established, and vibration response perpendicular to flow direction were investigated. Moreover, the safe range of the natural frequency of the square cylinder to avoid synchronized vibration with VIV is analyzed. The results of this paper can provide an important guidance to the design of the heat transfer tubes and their supports in HTR-PM.