DNS of Instantaneous Behavior in Turbulent Forced and Mixed Convection of Liquid Metal Past a Backward-Facing Step

doi:10.1007/s10494-020-00214-1

	DNS of Instantaneous Behavior in Turbulent Forced and Mixed Convection of Liquid Metal Past a Backward-Facing Step
	Wang, Chaozheng 2; Zhao, Pinghui 3; Lei, Mingzhun 3; Lu, Kun 3; Ge, Zhihao 2; Liu, Jiaming 2; Li, Yuanjie 2; Pei, Gang 1
刊名	FLOW TURBULENCE AND COMBUSTION
	2020-09-01
关键词	DNS Liquid metal Backward-facing step Instantaneous behavior Buoyancy
ISSN号	1386-6184
DOI	10.1007/s10494-020-00214-1
通讯作者	Zhao, Pinghui(phzhao@mail.ustc.edu.cn)
英文摘要	A direct numerical simulation has been performed to study instantaneous behavior in leadbismuth eutectic flows past a vertical, backward-facing step. A turbulent forced convection case and two cases of mixed convection, the first buoyancy-aided flow at a Richardson number Ri of 0.1 and the second buoyancy-opposed flow at Ri = 0.02, are simulated and discussed. The Reynolds number based on the bulk velocity and step height is 4805. A uniform heat flux is imposed on the expansion wall behind the step. In the forced convection case, the numerical results reveal two characteristic unsteady flow phenomena. The first is vortex-shedding motion along the separating shear layer, while the second is wall-normal flapping of the shear layer. These unsteady motions have significant influences on the thermal field. The vortex-shedding motion induces some streak-like low-temperature structures on the heated wall, while the flapping motion induces oscillation of the maximum temperature on the wall. In the mixed convection cases, buoyancy alters the flow field substantially. The two unsteady flow phenomena noted above constitute motions inherent to backwardfacing step flow. Buoyancy plays a material role in vortex development, affecting vortex ranges and time-scales. While the vortex shedding frequency is insensitive to buoyancy, the frequency of the flapping motion increases with the buoyancy. These results contribute to an improved understanding of separating and reattaching flows, especially in association with buoyancy and temperature fluctuations. The data serve to aid future development and validation of improved heat-flux modeling of low-Prandtl-number fluids.
资助项目	National Key R&D Program of China[2018YFB1900602] ; Collaborative Innovation Program of Hefei Science Center, CAS[2019HSC-CIP006]
WOS关键词	DIRECT NUMERICAL-SIMULATION ; LARGE-EDDY SIMULATION ; HEAT-TRANSFER ; FLOW
WOS研究方向	Thermodynamics ; Mechanics
语种	英语
出版者	SPRINGER
WOS记录号	WOS:000565144200001
资助机构	National Key R&D Program of China ; Collaborative Innovation Program of Hefei Science Center, CAS
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/70342]
专题	中国科学院合肥物质科学研究院
通讯作者	Zhao, Pinghui
作者单位	1.Univ Sci & Technol China, Sch Engn Sci, Hefei 230026, Peoples R China 2.Univ Sci & Technol China, Sch Phys Sci, Hefei 230026, Peoples R China 3.Chinese Acad Sci, Inst Plasma Phys, Hefei 230031, Peoples R China
推荐引用方式 GB/T 7714	Wang, Chaozheng,Zhao, Pinghui,Lei, Mingzhun,et al. DNS of Instantaneous Behavior in Turbulent Forced and Mixed Convection of Liquid Metal Past a Backward-Facing Step[J]. FLOW TURBULENCE AND COMBUSTION,2020.
APA	Wang, Chaozheng.,Zhao, Pinghui.,Lei, Mingzhun.,Lu, Kun.,Ge, Zhihao.,...&Pei, Gang.(2020).DNS of Instantaneous Behavior in Turbulent Forced and Mixed Convection of Liquid Metal Past a Backward-Facing Step.FLOW TURBULENCE AND COMBUSTION.
MLA	Wang, Chaozheng,et al."DNS of Instantaneous Behavior in Turbulent Forced and Mixed Convection of Liquid Metal Past a Backward-Facing Step".FLOW TURBULENCE AND COMBUSTION (2020).