Dual channels of helicity cascade in turbulent flows

doi:10.1017/jfm.2020.289

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

	Dual channels of helicity cascade in turbulent flows
	Yan Z(闫政)1,4; Li XL(李新亮)1,4; Yu ZP(于长平)1,4; Wang JC 2; Chen SY 2,3
刊名	JOURNAL OF FLUID MECHANICS
	2020-07-10
卷号	894 页码:13
关键词	homogeneous turbulence isotropic turbulence turbulence theory
ISSN号	0022-1120
DOI	10.1017/jfm.2020.289
英文摘要	Helicity, as one of only two inviscid invariants in three-dimensional turbulence, plays an important role in the generation and evolution of turbulent flows. Through theoretical analyses, we find that there are two channels in the helicity cascade process, which differs dramatically from the traditional viewpoint. In this paper, we have conducted important research on the newly proposed dual-channel helicity cascade theory, including vortex dynamic processes, intermittent discrepancies, tensor geometries, etc. The first channel mainly originates from the vortex twisting process, and the second channel mainly originates from the vortex stretching process. Antisymmetric tensors are introduced to the derivations of dual-channel helicity cascade theory, and a complex rotation frame leads to a higher helicity transfer efficiency. By analysing data from direct numerical simulations of typical turbulent flows, we find that these two channels behave differently. The ensemble averages of helicity flux in different channels are equal in homogeneous and isotropic turbulence, while they are different in other types of turbulent flows. The intermittency of the second channel is stronger than that of the first channel. In addition, we find a novel mechanism of hindered or even inverse energy cascades, which could be attributed to the second-channel helicity flux.
分类号	一类/力学重要期刊
WOS关键词	ENERGY
WOS研究方向	Mechanics ; Physics
语种	英语
WOS记录号	WOS:000529155000001
资助机构	National Natural Science Foundation of China (NSFC)[91852203] ; National Key Research and Development Program of China[2019YFA0405300] ; National Key Research and Development Program of China[2016YFA0401200]
其他责任者	Yu, Changping
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/84749]
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.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China; 2.Southern Univ Sci & Technol, Dept Mech & Aerosp Engn, Shenzhen 518055, Guangdong, Peoples R China; 3.Peking Univ, Coll Engn, Ctr Appl Phys & Technol, State Key Lab Turbulence & Complex Syst, Beijing 100871, Peoples R China 4.Chinese Acad Sci, Inst Mech, LHD, Beijing 100190, Peoples R China;
推荐引用方式 GB/T 7714	Yan Z,Li XL,Yu ZP,et al. Dual channels of helicity cascade in turbulent flows[J]. JOURNAL OF FLUID MECHANICS,2020,894:13.
APA	闫政,李新亮,于长平,Wang JC,&Chen SY.(2020).Dual channels of helicity cascade in turbulent flows.JOURNAL OF FLUID MECHANICS,894,13.
MLA	闫政,et al."Dual channels of helicity cascade in turbulent flows".JOURNAL OF FLUID MECHANICS 894(2020):13.