A neutrally buoyant circular particle motion in a double lid-driven cavity flow (LDCF) is investigated by immersed moving boundary based lattice Boltzmann method, where the top and bottom walls move with constant velocities. To understand the mechanism of particle motion in double LDCF, the influence of the moving wall velocity ratio , initial position, particle size, and Reynolds number on the trajectory and limit circle of the neutrally buoyant circular particle motion in double LDCF is systematically studied. The results show that the trajectory of the particle is obviously different with different afore impactors. As varies, the limit circle is changed accordingly. The limit circle of the particle motion is insensitive to the initial position with negative moving wall velocity ratio except for the initial location of the particle at the center of the cavity with = -1, where the particle is stationary all the time. When moving wall velocity ratio becomes positive, due to the more complex fluid structure or vortices in cavity, some interesting limit circle modes of particle motion are observed. When particle size increases, the confinement of cavity is enhanced. The limit circle shrinks to the center of the cavity, and it can be greatly changed with different particle size for . With the increment of Reynolds number, the flow is strengthened, and the influence domain and the strength of the secondary vortices are enhanced, where the limit circle of particle motion is pushed away from the secondary vortices generated in cavity. However, the limit circle mode of particle motion is insensitive to the Reynolds number varied from 500 to 5000.

中文翻译：

---

双盖驱动方形腔中的中性浮力粒子运动

通过基于浸入移动边界的格子玻尔兹曼方法研究了双盖驱动空腔流 (LDCF) 中的中性浮力圆形粒子运动，其中顶壁和底壁以恒定速度移动。为了解双LDCF中质点运动的机理，系统研究了动壁速度比、初始位置、颗粒尺寸和雷诺数对双LDCF中性浮力圆周质点运动轨迹和极限圆的影响。结果表明，不同的前撞击体，粒子的运动轨迹明显不同。随着变化，极限圆也随之变化。质点运动的极限圆对动壁速度比为负的初始位置不敏感，除了质点初始位置在空腔中心（= -1）时，质点始终处于静止状态。当动壁速度比变为正值时，由于腔内的流体结构或涡流更加复杂，观察到一些有趣的质点运动极限圆模式。当颗粒尺寸增大时，空腔的限制增强。极限圆收缩到型腔中心，并且随颗粒尺寸的不同而变化很大。随着雷诺数的增加，流动增强，二次涡的影响范围和强度增强，质点运动的极限圈被推离腔内产生的二次涡。然而，质点运动的极限圆模态对雷诺数500~5000不敏感。