SST model with flow transition for the forced vibration of a three-dimensional circular cylinder

Abstract

To study the relationship between the lift coefficient characteristics of a riser structure and the wake shedding mode under forced vibration, the SST model based on the two-equation transition is used to calculate the forced vibration of a rigid three-dimensional (3D) cylinder under a typical subcritical Reynolds number (Re=105). The model uses the overlapping mesh technology and the single-degree-of-freedom motion equation to simulate the cylindrical motion and two-equation transition model to improve the accuracy of numerical calculation. The influence of the amplitude ratio of the lateral forced vibration and the frequency of dimensionless vibration on the load characteristics of the cylinder fluid is studied, and the correlation between the lift coefficient and the wake shedding mode is analyzed. The results demonstrate that the jump drop of the fluctuating lift coefficient in the 3D case is delayed compared with that of the two-dimensional (2D) one. There are a few differences between 3D and 2D situations. The lift does not exhibit the attenuation phenomenon commonly observed in the usual "2P" mode due to the influence of the distribution of the 3D axial vortex.