Three-dimensional, time-dependent simulations of dense agitated solid-liquid suspensions involving particles of cylindrical shape in a Newtonian liquid have been performed. The liquid flow is resolved by the lattice-Boltzmann method at length scales finer than the size of the particles, which implies particle-resolved simulations. The flow solution includes the hydrodynamic forces and moments on each particle that are used to integrate their linear and rotational equations of motion. No-slip at the particle surfaces is imposed by an immersed boundary method (IBM). The marker points of the IBM are also used to detect and carry out collisions between particles. This numerical procedure has been applied to systems contained in a rectangular box and agitated by a revolving disk as well as by a pitched-blade turbine with an impeller-based Reynolds number of 87, which indicates laminar flow. The overall solids volume fraction has been fixed to 15%; the number of particles is of the order of one thousand. We study the effect of impeller type and particle shape (in terms of the length over diameter ratio of the cylinders that has been varied between 1 and 4) on the extent to which the solids are suspended and on the way the cylinders orient themselves.

牛顿液体中涉及圆柱状颗粒的稠密搅拌固液悬浮液的三维时变模拟已经完成。通过晶格-玻尔兹曼方法以比颗粒尺寸更细的长度尺度解析液体流动，这暗示了颗粒解析的模拟。流动解决方案包括每个粒子上的流体动力和力矩，这些流体动力和力矩用于积分其线性和旋转运动方程。粒子表面的无滑移是通过浸入边界方法（IBM）施加的。IBM的标记点还用于检测和执行粒子之间的碰撞。此数值程序已应用于包含在矩形盒中的系统，并由旋转盘以及由基于叶轮的雷诺数为87（表示层流）的变桨叶涡轮进行搅动。总固体体积分数已固定为15％；粒子的数量约为一千。我们研究了叶轮类型和颗粒形状（根据长度与直径之比在1至4之间变化的圆柱体）对固体悬浮程度以及圆柱体自身定向方式的影响。