Effect of expansion on the wall heat flux in a supersonic turbulent boundary layer

doi:10.1063/5.0113514

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

	Effect of expansion on the wall heat flux in a supersonic turbulent boundary layer
	Tong FL(童福林); Dong, Siwei; Duan JY(段俊亦); Yuan, Xianxu; Li XL(李新亮)
刊名	PHYSICS OF FLUIDS
	2022-10-01
卷号	34 期号:10 页码:21
ISSN号	1070-6631
DOI	10.1063/5.0113514
通讯作者	Yuan, Xianxu(yuanxianxu@cardc.cn)
英文摘要	Direct numerical simulation of a spatially developing supersonic turbulent boundary layer at a Mach number of 2.25 and a friction Reynolds number of Re-tau = 769 subjected to an expansion corner with a deflection angle of 12 degrees is performed to investigate the effect of expansion on the characteristics of the wall heat flux (WHF). The effect of expansion on the statistical and structural properties of the fluctuating WHF is analyzed systematically in terms of probability density function, frequency spectra, and space-time correlations. Normalization using the local root mean square value yields good collapse of the probability density function curves. Unlike with wall pressure frequency spectra, it is found that expansion has little influence on the low-frequency components of the WHF spectrum. The correlation results show that the main effect of expansion is to increase the characteristic length scales and convection velocity of the WHF fluctuation in the post-expansion region. Furthermore, a direct comparison between the conditionally averaged flow fields and those presented in the authors' previous work [Tong et at, Phys. Fluids 34, 015127 (2022)] is performed to uncover the effect of expansion on the flow structures associated with extreme positive and negative WHF fluctuation events. We highlight that the extreme positive event emerges below a small hot spot under the action of a strong Q4 event, whereas the extreme negative event is relatively insensitive to expansion and still occurs between a pair of strong oblique vortices. In addition, we decompose the mean WHF into seven physics-informed contributions and quantify the effect of expansion on the dominating components with the aid of the bidimensional empirical mode decomposition method. The scale-decomposed results demonstrate quantitatively that expansion decreases the contribution of the large-scale structures in the outer region but the small-scale structures in the near-wall region contribute heavily to the mean WHF generation in the downstream region. Published under an exclusive license by AIP Publishing.
分类号	一类/力学重要期刊
资助项目	National Natural Science Foundation of China ; [11972356] ; [12072306]
WOS关键词	DIRECT NUMERICAL-SIMULATION ; SHEAR-STRESS FLUCTUATIONS ; SHOCK-WAVE ; FLOW ; COMPRESSION ; DILATATION ; REGION ; CORNER
WOS研究方向	Mechanics ; Physics
语种	英语
WOS记录号	WOS:000888267100012
资助机构	National Natural Science Foundation of China
其他责任者	Yuan, Xianxu
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/91090]
专题	力学研究所_高温气体动力学国家重点实验室
推荐引用方式 GB/T 7714	Tong FL,Dong, Siwei,Duan JY,et al. Effect of expansion on the wall heat flux in a supersonic turbulent boundary layer[J]. PHYSICS OF FLUIDS,2022,34(10):21.
APA	童福林,Dong, Siwei,段俊亦,Yuan, Xianxu,&李新亮.(2022).Effect of expansion on the wall heat flux in a supersonic turbulent boundary layer.PHYSICS OF FLUIDS,34(10),21.
MLA	童福林,et al."Effect of expansion on the wall heat flux in a supersonic turbulent boundary layer".PHYSICS OF FLUIDS 34.10(2022):21.