Large eddy simulation of orientation and rotation of ellipsoidal particles in isotropic turbulent flows
Large eddy simulation of orientation and rotation of ellipsoidal particles in isotropic turbulent flows
复制标题
各向同性湍流中椭球粒子定向和旋转的大涡模拟
DOI：
10.1080/14685248.2015.1093638
复制
发表时间：
2016-03
影响因子：
1.9
通讯作者：
Zhang Jian
中科院分区：
文献类型：
--
作者：
Chen Jincai;Jin Guodong;Zhang Jian
湍流中椭球粒子的旋转运动和取向分布在环境和工程应用中具有重要意义。椭球粒子的平移运动在大尺度上受湍流运动控制，而其旋转运动在小尺度上由流体速度梯度张量决定，由于缺乏亚网格尺度（SGS）流体运动，这给利用大涡模拟（LES）方法预测椭球粒子的旋转弥散带来了挑战。我们报告了SGS流体运动对取向和旋转统计的影响，如椭球粒子长轴与涡度的对齐，以及不同纵横比下的平均旋转能量，与直接数值模拟（DNS）和滤波DNS得到的结果相比。研究了随机微分方程（SDE）模型对颗粒所看到的SGS速度梯度的性能，以及近似反卷积方法（ADM）对LES的性能。研究发现，在LES流场中缺失的SGS流体运动对椭球粒子的旋转统计量有显著影响。粒子与涡度之间的对齐减弱；粒子的旋转能量在LES中降低。SGS-SDE模型在预测粒子间的排列和涡度时存在较大误差，且对棒状粒子的旋转能预测过高。ADM显著改善了LES中粒子的旋转能预测。
ABSTRACT The rotational motion and orientational distribution of ellipsoidal particles in turbulent flows are of significance in environmental and engineering applications. Whereas the translational motion of an ellipsoidal particle is controlled by the turbulent motions at large scales, its rotational motion is determined by the fluid velocity gradient tensor at small scales, which raises a challenge when predicting the rotational dispersion of ellipsoidal particles using large eddy simulation (LES) method due to the lack of subgrid scale (SGS) fluid motions. We report the effects of the SGS fluid motions on the orientational and rotational statistics, such as the alignment between the long axis of ellipsoidal particles and the vorticity, the mean rotational energy at various aspect ratios against those obtained with direct numerical simulation (DNS) and filtered DNS. The performances of a stochastic differential equation (SDE) model for the SGS velocity gradient seen by the particles and the approximate deconvolution method (ADM) for LES are investigated. It is found that the missing SGS fluid motions in LES flow fields have significant effects on the rotational statistics of ellipsoidal particles. Alignment between the particles and the vorticity is weakened; and the rotational energy of the particles is reduced in LES. The SGS-SDE model leads to a large error in predicting the alignment between the particles and the vorticity and over-predicts the rotational energy of rod-like particles. The ADM significantly improves the rotational energy prediction of particles in LES.
登录
查看更多内容
粒子湍流大涡模拟中惯性粒子所看到的亚网格尺度流体速度时间尺度
DOI：
10.1016/j.ijmultiphaseflow.2009.12.005
发表时间：
2010-05
影响因子：
3.8
作者：
通讯作者：
--
影响因子：
4.6
作者：
W. Ames;C. Brezinski
通讯作者：
W. Ames;C. Brezinski
影响因子：
8.6
作者：
Chevillard, L.;Meneveau, C.
通讯作者：
Meneveau, C.
影响因子：
3.7
作者：
R. Ni;N. Ouellette;G. Voth
通讯作者：
R. Ni;N. Ouellette;G. Voth
影响因子：
1.9
作者：
Yue Yang;G. He;Lian-Ping Wang
通讯作者：
Yue Yang;G. He;Lian-Ping Wang