This paper focuses on fluid forces acting on a confined cylinder subjected to axial flow in application to fuel assembly dynamic behavior. From the literature, it is difficult to estimate the damping induced by the flow. Therefore, it is proposed to study numerically the damping fluid forces on a cylinder for various parameters. It has been observed that it increases with the smaller confinement and with the presence of an obstacle and decreases when the Reynolds number increases. Larger values correspond to a greater contribution of pressure forces. Dynamic simulations are compared to the steady ones and give different values, but the order of magnitude and general trend remain the same. Therefore, steady simulations are suitable to have a rough estimation of drag coefficients in dynamics.

中文翻译：

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轴流作用下带障碍物的受限圆柱体上流体力的数值研究

本文重点研究作用于受约束轴向流动的密闭气缸上的流体力，以应用于燃料组件的动态行为。根据文献，很难估计由流动引起的阻尼。因此，建议对各种参数的气缸上的阻尼流体力进行数值研究。已经观察到，它随着较小的限制和障碍物的存在而增加，并且随着雷诺数的增加而减少。值越大，压力的作用越大。将动态仿真与稳定仿真进行比较，并给出不同的值，但数量级和总体趋势保持不变。因此，稳定的模拟适合对动力学中的阻力系数进行粗略的估计。