In this study, the sedimentation of a torus is studied numerically over a range of Reynolds number spanning 10 $\le$ Re${}_{\mathrm{T}}$ $\le$ 90. The three-dimensional governing equations are solved using the fluid–structure interaction version of the SVD-GFD method on a hybrid Cartesian-cum-meshless grid. The torus has a fixed aspect ratio AR = 2, and is set to fall along the negative x direction at an initial inclination angle ${\theta }_0$, in the range of 0 $\le$ ${\theta }_0$ $\le$ 80°. The flow behavior induced by the falling torus is characterized by the far field vortex sheet and the near field recirculation zone. At a given Re${}_{\mathrm{T}}$, the flow reaches the same terminal state and the torus maintains the same final state, orientation and terminal velocity, regardless of ${\theta }_0$. The torus initially experiences a zigzag motion (along the x and z directions) in the global frame and the pitch motion in its body frame, which are more obvious at larger Re${}_{\mathrm{T}}$ and ${\theta }_0$. The offset of the torus centroid in the z direction between the initial and terminal states increases with increasing Re${}_{\mathrm{T}}$ and ${\theta }_0$ because of the ${\theta }_0$ effect. The falling time ($T_{\mathrm{f}}$) for the torus traveling along the same distance in the x direction decreases with increasing ${\theta }_0$ when Re${}_{\mathrm{T}}$ $\le$ 50. However, when Re${}_{\mathrm{T}}$ > 50, $T_{\mathrm{f}}$ initially increases and then decreases with increasing ${\theta }_0$, with the maximum $T_{\mathrm{f}}$ occurring at ${\theta }_0$ $\approx$ 60°. A lift-like force is generated in the positive x direction due to the translational torus motion in the z direction, which originates from the pressure. This force is most pronounced at ${\theta }_0$ $\approx$ 60° for Re${}_{\mathrm{T}}$ > 50, which thus significantly decelerates the falling speed of the torus and increases T${}_{\mathrm{f}}$.

在这项研究中，在雷诺数跨度为 10 的范围内对环面的沉降进行了数值研究 $\le$ 关于${}_{\mathrm{吨}}$ $\le$90. 三维控制方程使用 SVD-GFD 方法的流固耦合版本在混合笛卡尔和无网格网格上求解。环面具有固定的纵横比 AR = 2，并设置为以初始倾角沿负x方向落下${\theta }_0$, 在 0 范围内 $\le$ ${\theta }_0$ $\le$80°。下降环面引起的流动行为以远场涡旋片和近场回流区为特征。在给定的 Re${}_{\mathrm{吨}}$，流动达到相同的终端状态，环面保持相同的最终状态、方向和终端速度，无论 ${\theta }_0$. 环面最初在全局坐标系中经历了锯齿形运动（沿x和z方向），在其主体坐标系中经历了俯仰运动，这在较大的 Re 时更为明显${}_{\mathrm{吨}}$ 和 ${\theta }_0$. 初始状态和终止状态之间的环面质心在z方向上的偏移量随着 Re 的增加而增加${}_{\mathrm{吨}}$ 和 ${\theta }_0$ 因为 ${\theta }_0$影响。下降时间（${吨}_{\mathrm{F}}$) 对于在x方向沿相同距离行进的环面随着增加而减少${\theta }_0$ 当再${}_{\mathrm{吨}}$ $\le$ 50.然而，当Re${}_{\mathrm{吨}}$ > 50, ${吨}_{\mathrm{F}}$ 开始增加，然后随着增加而减少 ${\theta }_0$, 最大 ${吨}_{\mathrm{F}}$ 发生在 ${\theta }_0$ $\approx$60°。由于来自压力的z方向的平移圆环运动，在正x方向产生类似升力的力。这种力在${\theta }_0$ $\approx$ Re 60°${}_{\mathrm{吨}}$ > 50，从而显着降低环面的下降速度并增加 T${}_{\mathrm{F}}$.