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

doi:10.1063/5.0113514

	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)
通讯作者	Yuan, Xianxu(yuanxianxu@cardc.cn)
发表期刊	PHYSICS OF FLUIDS
	2022-10-01
卷号	34 期号:10 页码:21
ISSN	1070-6631
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.
DOI	10.1063/5.0113514
收录类别	SCI ; EI
语种	英语
WOS记录号	WOS:000888267100012
关键词[WOS]	DIRECT NUMERICAL-SIMULATION ; SHEAR-STRESS FLUCTUATIONS ; SHOCK-WAVE ; FLOW ; COMPRESSION ; DILATATION ; REGION ; CORNER
WOS研究方向	Mechanics ; Physics
WOS类目	Mechanics ; Physics, Fluids & Plasmas
资助项目	National Natural Science Foundation of China ; [11972356] ; [12072306]
项目资助者	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	3
RpAuthor	Yuan, Xianxu
引用统计	被引频次：6[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/311007/91091
专题	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.

条目包含的文件		下载所有文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
Jp2022FA136_2022_Eff（8019KB）	期刊论文	出版稿	开放获取	CC BY-NC-SA	浏览下载