In this study a theoretical study is carried out on the binary collision of round-sided disks (RSD) suspended in a Newtonian fluid under a simple shear flow. RSD is composed of a disk part and a half-torus part which circumscribes the side of the disk. The diameter of the disk is fixed at 2 µm while the thickness and the half-torus size are varied so that the aspect ratio varies from 0.13 to 0.288. The liquid viscosity is changed from 0.01 to 1 Pa·s. The hydrodynamic force and van der Waals force with the Hamaker constant of 1.06 × 10⁻²⁰ J are considered in tracking the position and the orientation of each particle. The Brownian motion is considered to be negligible. The collision of two particles initially separated by sufficiently a long distance is considered and the kinetic constant of coagulation is obtained by considering the presence of collision, the orientations of two particles and the flux of liquid flow. The result shows that the kinetic constant of coagulation is reduced to approximately 1/4 of the kinetic constant of non-interacting particles by the hydrodynamic interaction when the viscosity is 1 Pa·s. As collision modes, side-side and side-edge are considered. Side-side mode is found to be the dominant mode of collision for differing aspect ratio and differing viscosity of the liquid. The dominance of the side-side collision mode implies the formation of two-dimensional flocs in the shear flow.

中文翻译：

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简单剪切流作用下圆盘形颗粒的凝聚动力学

在这项研究中，对在简单剪切流作用下悬浮在牛顿流体中的圆盘（RSD）的二元碰撞进行了理论研究。RSD由一个磁盘部分和一个外接磁盘的半托部分组成。圆盘的直径固定为2 µm，同时厚度和半托尺寸也有所变化，以使纵横比在0.13至0.288之间变化。液体粘度从0.01变为1Pa·s。Hamaker常数为1.06×10 ^-20的流体动力和范德华力在跟踪每个粒子的位置和方向时考虑J。布朗运动被认为可以忽略不计。考虑最初相隔足够长的距离的两个粒子的碰撞，并通过考虑碰撞的存在，两个粒子的取向和液体流动通量来获得凝结的动力学常数。结果显示，当粘度为1Pa·s时，通过水动力相互作用，凝固的动力学常数降低至非相互作用颗粒的动力学常数的约1/4。作为碰撞模式，考虑了侧面和侧面边缘。对于不同的纵横比和不同的液体粘度，发现侧面模式是碰撞的主要模式。