摘要
采用扩散界面格子Boltzmann模型研究了圆形颗粒在幂律流体方腔流中的运动,重点分析了初始位置、幂律指数、颗粒大小对圆形颗粒在幂律流体顶盖驱动流中的运动的影响.数值结果表明不同初始位置的圆形颗粒最终均能稳定在极限环上运动.不同幂律指数的幂律流体对圆形颗粒运动的极限环有明显影响,对于剪切增稠流体,颗粒的运动速度明显增大,极限环半径明显缩小;对于剪切稀化流体,左下角和右下角的次级涡收缩,极限环向方腔的右下角移动.圆形颗粒较小时,颗粒的运动速度较快,运动半径较大,运动轨迹更接近流体的流线;圆形颗粒较大时,受到边界的限制,极限环半径较小,运动速度较慢.此外,还讨论了颗粒对顶盖驱动流主涡涡心位置的影响,颗粒会将主涡涡心推向远离颗粒的方向.
Abstract
In this paper,the motion of a circular particle in a lid-driven square cavity with the power-law fluid is studied by using the diffuse interface lattice Boltzmann method,and the study mainly considers the effects of the particle's initial position,the power-law index,the Reynolds number,and the particle size.The numerical results show that the circular particle is first in a centrifugal motion under the effect of inertia,and it finally moves steadily on the limit cycle.Furthermore,it is also found that the initial position of the particle has no influence on the limit cycle.For a shear-thinning fluid flow,the limit cycle moves towards the bottom right corner of the square cavity.Moreover,the particle velocity is small,and the period of the particle motion is long.On the other hand,in the case of shear-thickening fluid flow,the limit cycle moves towards the top left corner of the cavity.In addition,the particle velocity is large,and the period of the particle motion is short.With the increase of Reynolds number,the limit cycle moves towards the bottom right corner of the square cavity,which is caused by a strong fluid flow field.Meanwhile,the particle velocity becomes larger,and the period of the particle motion is shorter.With the increase of particle size,the effect of confinement of the cavity boundary becomes significant,and the circular particle is pushed towards the center of the cavity.In this case,the limit cycle shrinks towards the center of the cavity.The circular particle squeezes the secondary vortices,especially when the circular particle is located in the bottom left,bottom right and top left corners.Additionally,the appearance of the circular particle has a significant influence on the position of the primary vortex,which changes periodically near the position of the primary vortex without the particle.It is also observed that the influence of the circular particle becomes more significant as its size increases and the power-law index decreases.
基金项目
国家自然科学基金(12072127)
国家自然科学基金(123B2018)
华中科技大学交叉研究支持计划(2023JCJY002)
华中科技大学交叉研究支持计划(2024JCYJ001)
中央高校基本科研业务费(YCJJ20241101)
中央高校基本科研业务费(2023JY-CXJJ046)
国家科技期刊平台
NSTL
万方数据