arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1003.4588math.NAcs.NAphysics.comp-phphysics.flu-dyn
收藏

颗粒流模拟中的时间离散化

On discretization in time in simulations of particulate flows

Institut de Mathématiques de Toulouse, Université de Toulouse(图卢兹数学研究所,图卢兹大学)

Matthieu Hillairet, Alexei Lozinski, Marcela Szopos

AI总结:

针对流体/颗粒流模拟中的常微分方程,提出一种在润滑 regime 下鲁棒的时间离散化方案,通过引入阈值近似粒子轨迹,并理论及实验验证误差,可集成到全模拟方法中。

摘要:

我们针对流体/颗粒流模拟中出现的一类常微分方程提出了一种时间离散化方案。该方案旨在润滑 regime 下鲁棒工作,即当浸没在流体中的两个粒子之间或粒子与壁面之间的距离趋于零时。其思想是引入一个小的粒子-壁面距离阈值,低于该阈值时,粒子的真实轨迹被替换为近似轨迹,其中距离保持等于阈值。通过理论和数值实验估计了该近似的误差。我们的时间推进方案可以轻松集成到全模拟方法中,其中流体速度通过斯托克斯或纳维-斯托克斯方程的数值解获得。我们还提供了润滑力(用于我们的数值实验)的渐近展开推导,该力作用于浸没在牛顿流体中并接近壁面的圆盘。该推导方法是新的,并且可以轻松适应其他情况。

英文摘要:

We propose a time discretization scheme for a class of ordinary differential equations arising in simulations of fluid/particle flows. The scheme is intended to work robustly in the lubrication regime when the distance between two particles immersed in the fluid or between a particle and the wall tends to zero. The idea consists in introducing a small threshold for the particle-wall distance below which the real trajectory of the particle is replaced by an approximated one where the distance is kept equal to the threshold value. The error of this approximation is estimated both theoretically and by numerical experiments. Our time marching scheme can be easily incorporated into a full simulation method where the velocity of the fluid is obtained by a numerical solution to Stokes or Navier-Stokes equations. We also provide a derivation of the asymptotic expansion for the lubrication force (used in our numerical experiments) acting on a disk immersed in a Newtonian fluid and approaching the wall. The method of this derivation is new and can be easily adapted to other cases.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑