Turbulence structure of the Rayleigh-Bénard convection using liquid CO<sub>2</sub> as working fluid

doi:10.1063/5.0173929

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	Turbulence structure of the Rayleigh-Bénard convection using liquid CO₂ as working fluid
	Zhao YF(赵一凡)1,2; Wu D(吴笛)1 ; Duan LS(段隆盛)1,3 ; Wang J(王佳)1; Li, Jialiang 2; Duan L(段俐)1,4 ; Kang Q(康琦)1,4
通讯作者	Wang, Jia(wangjia@imech.ac.cn) ; Li, Jialiang(lijialiang@sdust.edu.cn) ; Duan, Li(duanli@imech.ac.cn)
发表期刊	PHYSICS OF FLUIDS
	2024
卷号	36 期号:1 页码:15
ISSN	1070-6631
摘要	We studied the evolution of flow structures and large-scale circulations (LSC) in Rayleigh-B & eacute;nard convection (RBC) using liquid carbon dioxide as the working medium. In this experiment, a transparent sapphire pressure vessel with observable internal flow was designed, and different temperature differences were applied between the upper and the lower surfaces of the fluid to obtain different Rayleigh numbers (Ra). We employed proper orthogonal decomposition and reconstruction to extract internal flow structures from the shadowgraphy images. We used optical flow techniques to acquire the velocity field of the flow, and we reconstructed the temperature field inside the supercritical fluid using the relationship between shadowgraphy images and refractive index. It is clearly observed that the RBC begins to produce different flow structures under a small temperature difference of 0.4 degrees C. As the number of Ra increases, the number and the speed of plumes increase, and the morphology of plumes gradually becomes elongated. When Ra exceeds a certain critical value, an LSC structure appears in the flow field, and the plumes translate laterally with the large-scale circulation, and the disorder of the vortex structure in the central flow region increases significantly. Three typical flow structures were observed: (1) single plume, (2) thermal boundary layer traveling waves, and (3) Rayleigh-Taylor instability waves. We believe that the traveling wave structure is the precursor to the single plume. The temperature field analysis of the three structures was carried out, and the velocity of the typical plume was calculated by the optical flow method. It was found that LSC transitioned from oval to square shape with the increase in Ra, and the internal plume Reynolds number slowly increased with the increase in Ra. By the in-depth study of the thermal turbulence characteristics and the coherent structure evolution law of RBC, this paper provides experimental support for revealing the mechanism of enhanced heat transfer in energy system with a liquid CO2 working fluid.
DOI	10.1063/5.0173929
收录类别	SCI ; EI
语种	英语
WOS记录号	WOS:001145847500001
关键词[WOS]	RAYLEIGH-BENARD CONVECTION ; VELOCITY-FIELD ; FLOW ; DYNAMICS ; PLUMES
WOS研究方向	Mechanics ; Physics
WOS类目	Mechanics ; Physics, Fluids & Plasmas
资助项目	China Manned Space Engineering Program (Fluid Physics Experimental Rack) ; China Manned Space Engineering Program (Priority Research Program of Space Station) ; National Natural Science Foundation of China[12032020] ; National Natural Science Foundation of China[12072354] ; National Natural Science Foundation of China[12102438]
项目资助者	China Manned Space Engineering Program (Fluid Physics Experimental Rack) ; China Manned Space Engineering Program (Priority Research Program of Space Station) ; National Natural Science Foundation of China
论文分区	一类/力学重要期刊
力学所作者排名	1
RpAuthor	Wang, Jia ; Li, Jialiang ; Duan, Li
引用统计
文献类型	期刊论文
条目标识符	http://dspace.imech.ac.cn/handle/311007/94523
专题	微重力重点实验室
作者单位	1.Chinese Acad Sci, Key Lab Micrograv, Inst Mech, Beijing 100190, Peoples R China; 2.Shandong Univ Sci & Technol, Coll Energy & Min Engn, Qingdao 266590, Peoples R China; 3.Beijing Syst Design Inst Electromech Engn, Beijing 100039, Peoples R China; 4.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Zhao YF,Wu D,Duan LS,et al. Turbulence structure of the Rayleigh-Bénard convection using liquid CO₂ as working fluid[J]. PHYSICS OF FLUIDS,2024,36,1,:15.
APA	赵一凡.,吴笛.,段隆盛.,王佳.,Li, Jialiang.,...&康琦.(2024).Turbulence structure of the Rayleigh-Bénard convection using liquid CO₂ as working fluid.PHYSICS OF FLUIDS,36(1),15.
MLA	赵一凡,et al."Turbulence structure of the Rayleigh-Bénard convection using liquid CO₂ as working fluid".PHYSICS OF FLUIDS 36.1(2024):15.