The effects of particle shape on settling behavior of sand particles under the influence of gravity in an initially quiescent water environment have been studied by a two-dimensional high-resolution numerical experiment. The numerical method is based on an immersed boundary method. The accuracy of the code is well demonstrated against experimental data of a fluttering rectangular plate. The particle is either elliptical or rectangular of size about 1 mm, and the particle aspect ratio is varied without changing the volume. The particle-to-fluid density ratio is chosen to be 2.65, and the resulting Galileo number is about 127. It is found that the terminal settling velocity tends to decrease with an increase in the aspect ratio and that the settling velocity of a rectangle is always lower than that of the corresponding ellipse in both the isolated and multiple particle systems. While the presence of surrounding particles makes the influence of the particle shape less clear, the circular particle still presents significant differences in the terminal settling velocity compared with the other particles. It, therefore, calls for caution in the spherical assumption of particle shape and encourages a deeper understanding of the particle shape effects.

通过二维高分辨率数值实验研究了颗粒形状对初始静止水环境中重力影响下砂粒沉降行为的影响。数值方法基于浸入边界法。与颤振矩形板的实验数据相比，代码的准确性得到了很好的证明。颗粒为椭圆形或矩形，大小约1mm，颗粒长宽比变化，体积不变。粒子与流体的密度比选择为 2.65，得到的伽利略数约为 127。发现随着纵横比的增加，最终沉降速度趋于降低，并且在孤立和多粒子系统中，矩形的沉降速度总是低于相应椭圆的沉降速度。虽然周围颗粒的存在使得颗粒形状的影响不太明显，但与其他颗粒相比，圆形颗粒在终端沉降速度方面仍然存在显着差异。因此，它要求谨慎使用粒子形状的球形假设，并鼓励更深入地了解粒子形状效应。与其他颗粒相比，圆形颗粒在终端沉降速度方面仍然存在显着差异。因此，它要求谨慎使用粒子形状的球形假设，并鼓励更深入地了解粒子形状效应。与其他颗粒相比，圆形颗粒在终端沉降速度方面仍然存在显着差异。因此，它要求谨慎使用粒子形状的球形假设，并鼓励更深入地了解粒子形状效应。