Localizing effect of Langmuir circulations on small-scale turbulence in shallow water

doi:10.1017/jfm.2020.215

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	Localizing effect of Langmuir circulations on small-scale turbulence in shallow water
	Deng BQ 1,2; Yang ZX(杨子轩)1,2,3; Xuan AQ 1,2; Shen L 1,2
通讯作者	Shen Lian(shen@umn.edu)
发表期刊	JOURNAL OF FLUID MECHANICS
	2020-06-25
卷号	893 页码:38
ISSN	0022-1120
摘要	Wall-resolved and wall-modelled large-eddy simulations are performed to study the localizing effect of Langmuir cells (LCs) on small-scale background turbulence in shallow water. The total velocity fluctuations are decomposed into an LC content extracted by streamwise averaging and a background turbulence part. Based on the large-scale motions of LCs, the spanwise domain is divided into three regions dominated by the upwelling, spanwise and downwelling flows of LCs, respectively. The localized Reynolds stresses in different spanwise regions are compared to show the localizing effects of the LCs on the background turbulence quantitatively, where (or ), (or ) and (or ) represent the streamwise, vertical and spanwise components of the background turbulence velocity, respectively, and denotes time and streamwise averaging. It is shown that the magnitudes of the localized Reynolds stresses in different spanwise regions vary significantly. The transport equations of the localized Reynolds stresses are then analysed to investigate the mechanisms underlying the localizing effects. It is discovered that the difference in the energy production correlated to the shear of the LC content among different regions is the key factor that leads to the localization of background turbulence. In addition, the energy production correlated to the shear of the mean flow, the energy redistribution due to the pressure-strain correlation, and the interaction between the localized Reynolds stresses and the shear of the Stokes drift also play important roles. Based on the results obtained from the analysis of the transport equations, predictive models are proposed for the localizing effects, which assess the spatial dependence of the Boussinesq model for background turbulence in coastal Langmuir turbulence. These models show good scaling performance of near the water bottom and of , and in the central region of the water column under various flow conditions with different values of the Reynolds number, turbulent Langmuir number and wavenumber.
关键词	turbulence simulation wave-turbulence interactions turbulent boundary layers
DOI	10.1017/jfm.2020.215
收录类别	SCI ; EI
语种	英语
WOS记录号	WOS:000526359400001
关键词[WOS]	SURFACE BOUNDARY-LAYER ; LARGE-EDDY SIMULATION ; AMPLITUDE-MODULATION ; OCEAN ; WIND ; SUPERCELLS ; FLOW ; ENERGETICS ; MECHANISM ; DYNAMICS
WOS研究方向	Mechanics ; Physics
WOS类目	Mechanics ; Physics, Fluids & Plasmas
资助项目	Office of Naval Research ; Minnesota Sea Grant ; National Science Foundation
项目资助者	Office of Naval Research ; Minnesota Sea Grant ; National Science Foundation
论文分区	一类/力学重要期刊
力学所作者排名	2
RpAuthor	Shen Lian
引用统计	被引频次：3[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://dspace.imech.ac.cn/handle/311007/81877
专题	非线性力学国家重点实验室
作者单位	1.Univ Minnesota, Dept Mech Engn, Minneapolis, MN 55414 USA; 2.Univ Minnesota, St Anthony Falls Lab, Minneapolis, MN 55414 USA; 3.Chinese Acad Sci, Inst Mech, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Deng BQ,Yang ZX,Xuan AQ,et al. Localizing effect of Langmuir circulations on small-scale turbulence in shallow water[J]. JOURNAL OF FLUID MECHANICS,2020,893:38.
APA	Deng BQ,杨子轩,Xuan AQ,&Shen L.(2020).Localizing effect of Langmuir circulations on small-scale turbulence in shallow water.JOURNAL OF FLUID MECHANICS,893,38.
MLA	Deng BQ,et al."Localizing effect of Langmuir circulations on small-scale turbulence in shallow water".JOURNAL OF FLUID MECHANICS 893(2020):38.

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