Effects of streamwise rotation on helicity and vortex in channel turbulence

doi:10.1017/jfm.2024.37

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

	Effects of streamwise rotation on helicity and vortex in channel turbulence
	Hu, Running 1,2; Li, Xinliang 1,2; Yu, Changping 2
刊名	JOURNAL OF FLUID MECHANICS
	2024-02-08
卷号	980 页码:30
关键词	rotating turbulence channel flow turbulence simulation
ISSN号	0022-1120
DOI	10.1017/jfm.2024.37
通讯作者	Yu, Changping(cpyu@imech.ac.cn)
英文摘要	Helicity plays a key role in the evolution of vortex structures and turbulent dynamics. The helicity dynamics and vortex structures in streamwise-rotating channel turbulence are discussed in this paper using the helicity budget equation and the differentiated second-order structure function equation of helicity. Generally, rotation and Reynolds numbers exhibit opposing effects on the interscale helicity dynamics and the vortices. Under the buffer layer, the positions of the helicity peaks are proportional to the ratio between the Reynolds and rotation numbers. The mechanism is related to the opposing effects of convection and rotation. Rotation directly affects the helicity balance through the Coriolis term and corresponding pressure term. In the buffer layer, the scale helicity is negative at small scales but positive at large scales, which is mainly induced by the spatial effects (the production and the spatial turbulent convection) but reduced by interscale cascades. Examination of structures reveals the close association between scale helicity and streaks, with streak lift angles exhibiting an increase with rotation and a decrease with Reynolds numbers. In the log-law layer, the Coriolis terms and corresponding pressure terms are proportional to the rotation numbers but remain independent of the Reynolds numbers. The negative scale helicity is forward cascaded towards small scales. Generally, spanwise vortices in the log-law layer are related to sweep events and forward cascades. Our findings indicate that these spanwise vortices are suppressed by rotation but recover with increasing Reynolds numbers, aligning with the effects observed in the scale helicity balance.
资助项目	National Key Research and Development Program of China[2020YFA0711800] ; National Key Research and Development Program of China[2019YFA0405300] ; NSFC[12072349] ; NSFC[12232018] ; NSFC[91852203] ; NSFC[12202457]
WOS关键词	DIRECT NUMERICAL-SIMULATION ; FLOW ; ENERGY ; GENERATION ; DYNAMICS ; CASCADE
WOS研究方向	Mechanics ; Physics
语种	英语
WOS记录号	WOS:001157327300001
资助机构	National Key Research and Development Program of China ; NSFC
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/94436]
专题	力学研究所_高温气体动力学国家重点实验室
通讯作者	Yu, Changping
作者单位	1.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China 2.Chinese Acad Sci, Inst Mech, LHD, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Hu, Running,Li, Xinliang,Yu, Changping. Effects of streamwise rotation on helicity and vortex in channel turbulence[J]. JOURNAL OF FLUID MECHANICS,2024,980:30.
APA	Hu, Running,Li, Xinliang,&Yu, Changping.(2024).Effects of streamwise rotation on helicity and vortex in channel turbulence.JOURNAL OF FLUID MECHANICS,980,30.
MLA	Hu, Running,et al."Effects of streamwise rotation on helicity and vortex in channel turbulence".JOURNAL OF FLUID MECHANICS 980(2024):30.