| Dual channels of helicity cascade in turbulent flows | |
Yan Z(闫政)1,2; Li XL(李新亮)1,2 ; Yu ZP(于长平)1,2; Wang JC3; Chen SY3,4
| |
| Source Publication | JOURNAL OF FLUID MECHANICS
 |
| 2020-07-10 | |
| Volume | 894Pages:13 |
| ISSN | 0022-1120 |
| Abstract | 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. |
| Keyword | homogeneous turbulence isotropic turbulence turbulence theory |
| DOI | 10.1017/jfm.2020.289 |
| Indexed By | SCI ; EI |
| Language | 英语 |
| WOS ID | WOS:000529155000001 |
| WOS Keyword | ENERGY |
| WOS Research Area | Mechanics ; Physics |
| WOS Subject | Mechanics ; Physics, Fluids & Plasmas |
| Funding Organization | 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] |
| Classification | 一类/力学重要期刊 |
| Ranking | 1 |
| Contributor | Yu, Changping |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://dspace.imech.ac.cn/handle/311007/84749 |
| Collection | 高温气体动力学国家重点实验室 |
| Affiliation | 1.Chinese Acad Sci, Inst Mech, LHD, Beijing 100190, Peoples R China; 2.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China; 3.Southern Univ Sci & Technol, Dept Mech & Aerosp Engn, Shenzhen 518055, Guangdong, Peoples R China; 4.Peking Univ, Coll Engn, Ctr Appl Phys & Technol, State Key Lab Turbulence & Complex Syst, Beijing 100871, Peoples R China |
| Recommended Citation 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.Rp_Au:Yu, Changping |
| 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. |
| Files in This Item: | Download All | |||||
| File Name/Size | DocType | Version | Access | License | ||
| Jp2020193.pdf（609KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Download | |
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment