Spatial correlations and relative velocities of polydisperse droplets in homogeneous isotropic turbulence

doi:10.1063/5.0101945

CORC > 力学研究所 > 中国科学院力学研究所 > 高温气体动力学国家重点实验室

	Spatial correlations and relative velocities of polydisperse droplets in homogeneous isotropic turbulence
	Zhu HY(朱航宇); Pan, Chong 2,4; Lian H(连欢)
刊名	PHYSICS OF FLUIDS ; 8
	2022-08
卷号	34 页码:83320
ISSN号	1070-6631
DOI	10.1063/5.0101945
英文摘要	We investigate the motions of polydisperse droplets in homogeneous and isotropic turbulence at Reynolds numbers Re-lambda = 200-300. The emphasize is put on the parameter dependences of spatial velocity correlations (SVCs) and relative velocities (RVs) of droplets, which are relevant to particle transport and dispersion in turbulence and have been less studied in experiments. The Kolmogorov-scale Stokes number is St(p) = 10(-1)-10(1), and the settling parameter, i.e., the ratio of particle settling velocity to fluid velocity fluctuations, is Sv(L) = 0.5-2.0. Using high-resolution measurements, we can resolve the motions of turbulence and droplet over a wide range of scales (10(-1)eta to 10(2)eta, eta is Kolmogorov length). The parabolic behavior in droplet SVCs near the origin is observed, similar to turbulence. The droplet SVCs are smaller than turbulence for all scales and decrease with both St(p) and Sv(L). At large scales, the droplet RVs, smaller than those of turbulence due to the inertial filtering effect, also decrease with St(p) and Sv(L). At small scales, the path-history effect leads to larger droplet RVs than fluid RVs. Interestingly, we find RVs present a non-monotonic trend with St(p) and reach a valley at St(p) asymptotic to 1.0. It may originate from particle clustering and preferential sweeping effects, which both prevail at St(p) asymptotic to 1.0. It is also found that droplet motions are less intermittent than turbulence. This is in contrast to the previous observations by simulations with the gravity effect being ignored. The intermittency of droplet RVs decreases with Sv(L) due to the diminished droplet-turbulence interactions, and it presents opposite trends with St(p) for small and large scales. Finally, the balance between the effects of path histories and turbulent structures makes the velocity statistics of droplets quasi-independent from the scale in the range of the dissipative scale (r (sic) 5 eta). Published under an exclusive license by AIP Publishing.
学科主题	Mechanics ; Physics, Fluids & Plasmas
分类号	一类/力学重要期刊
语种	英语
WOS记录号	WOS:000860700800006
资助机构	National Natural Science Foundation of China (NSFC) [91941104, 11872366]
其他责任者	Lian, H (corresponding author), Chinese Acad Sci, Inst Mech, State Key Lab High Temp Gas Dynam, Beijing 100190, Peoples R China.
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/90209]
专题	力学研究所_高温气体动力学国家重点实验室
作者单位	1.Beihang Univ, Ningbo Inst Technol, Aircraft & Prop Lab, Ningbo 315800, Peoples R China 2.Southern Univ Sci & Technol, Dept Mech & Aerosp Engn, Shenzhen 518055, Peoples R China 3.Beihang Univ, Fluid Mech Key Lab Educ Minist, Beijing 100191, Peoples R China 4.Chinese Acad Sci, Inst Mech, State Key Lab High Temp Gas Dynam, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Zhu HY,Pan, Chong,Lian H. Spatial correlations and relative velocities of polydisperse droplets in homogeneous isotropic turbulence[J]. PHYSICS OF FLUIDS, 8,2022,34:83320.
APA	朱航宇,Pan, Chong,&连欢.(2022).Spatial correlations and relative velocities of polydisperse droplets in homogeneous isotropic turbulence.PHYSICS OF FLUIDS,34,83320.
MLA	朱航宇,et al."Spatial correlations and relative velocities of polydisperse droplets in homogeneous isotropic turbulence".PHYSICS OF FLUIDS 34(2022):83320.