The effects of four different incidence angles (α) on the vortex-induced vibration (VIV) response of a two degrees-of-freedom cylinder were studied using the two-dimensional unsteady Reynolds-averaged Navier-Stokes equation and shear stress transport k-ω model, combined with the fourth-order Runge-Kutta method. The VIV characteristics, including the structural vibration amplitude, vibration frequency, lock-in regime, the pattern of vortex shedding, Strouhal number, hydrodynamic coefficient, and power conversion efficiency were systematically researched. The numerical results showed that a change of the incidence angle made the VIV response of the cylinder display multifrequency characteristics. As the incidence angle increased, the amplitude in the y direction gradually decreased; comparatively, the amplitude in the x direction gradually increased. The VIV responses for different incidence angles all presented an obvious lock-in phenomenon; however, the width of lock-in region changed slightly with variation of the incidence angle. As the incidence angle increased, the root-mean-square value of the hydrodynamic force coefficient in the y direction and the mean value of the hydrodynamic force coefficient in the x direction both had a decreasing tendency.

使用二维非定常雷诺平均 Navier-Stokes 方程和剪切应力传输k-研究了四种不同入射角 ( α ) 对两个自由度圆柱体的涡激振动 (VIV) 响应的影响ω模型，结合四阶 Runge-Kutta 方法。系统研究了VIV特性，包括结构振幅、振动频率、锁定状态、涡旋脱落模式、斯特劳哈尔数、水动力系数和功率转换效率。数值结果表明，入射角的变化使圆柱体的VIV响应呈现出多频特性。随着入射角的增加，y方向逐渐减小；相对而言，x方向的幅度逐渐增大。不同入射角的VIV响应均呈现明显的锁定现象；然而，锁定区域的宽度随着入射角的变化而略有变化。随着入射角的增大，y方向水动力系数的均方根值和x方向水动力系数的均值均呈下降趋势。