Large-eddy simulation of turbulent collision of heavy particles in isotropic turbulence

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	Large-eddy simulation of turbulent collision of heavy particles in isotropic turbulence
	Jin GD(晋国栋); He GW(何国威); Wang LP
刊名	Physics of Fluids
	2010
通讯作者邮箱	hgw@lnm.imech.ac.cn ;guoweihe@yahoo.com
卷号	22 期号:5 页码:055106
关键词	two-phase flow multiphase flow particle-laden flow large-eddy simualtion subgrid scale turbulence
ISSN号	1070-6631
通讯作者	何国威
合作状况	其它
中文摘要	The small-scale motions relevant to the collision of heavy particles represent a general challenge to the conventional large-eddy simulation (LES) of turbulent particle-laden flows. As a first step toward addressing this challenge, we examine the capability of the LES method with an eddy viscosity subgrid scale (SGS) model to predict the collision-related statistics such as the particle radial distribution function at contact, the radial relative velocity at contact, and the collision rate for a wide range of particle Stokes numbers. Data from direct numerical simulation (DNS) are used as a benchmark to evaluate the LES using both a priori and a posteriori tests. It is shown that, without the SGS motions, LES cannot accurately predict the particle-pair statistics for heavy particles with small and intermediate Stokes numbers, and a large relative error in collision rate up to 60% may arise when the particle Stokes number is near St_K=0.5. The errors from the filtering operation and the SGS model are evaluated separately using the filtered-DNS (FDNS) and LES flow fields. The errors increase with the filter width and have nonmonotonic variations with the particle Stokes numbers. It is concluded that the error due to filtering dominates the overall error in LES for most particle Stokes numbers. It is found that the overall collision rate can be reasonably predicted by both FDNS and LES for St_K>3. Our analysis suggests that, for St_K<3, a particle SGS model must include the effects of SGS motions on the turbulent collision of heavy particles. The spectral analysis of the concentration fields of the particles with different Stokes numbers further demonstrates the important effects of the small-scale motions on the preferential concentration of the particles with small Stokes numbers.
学科主题	流体力学
类目[WOS]	Mechanics ; Physics, Fluids & Plasmas
研究领域[WOS]	Mechanics ; Physics
关键词[WOS]	DIRECT NUMERICAL SIMULATIONS ; INERTIAL PARTICLES ; PREFERENTIAL CONCENTRATION ; HOMOGENEOUS TURBULENCE ; FLOW ; MOTION ; DISPERSION ; VELOCITY ; CHANNEL ; SCALES
收录类别	SCI
语种	英语
WOS记录号	WOS:000278183000043
公开日期	2010-05-25
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/33086]
专题	力学研究所_非线性力学国家重点实验室
推荐引用方式 GB/T 7714	Jin GD,He GW,Wang LP. Large-eddy simulation of turbulent collision of heavy particles in isotropic turbulence[J]. Physics of Fluids,2010,22(5):055106.
APA	晋国栋,何国威,&Wang LP.(2010).Large-eddy simulation of turbulent collision of heavy particles in isotropic turbulence.Physics of Fluids,22(5),055106.
MLA	晋国栋,et al."Large-eddy simulation of turbulent collision of heavy particles in isotropic turbulence".Physics of Fluids 22.5(2010):055106.