Contribution of flow topology to the kinetic energy flux in hypersonic turbulent boundary layer

Xu, Dehao1; Wang, Jianchun2; Yu, Changping3; Li, Xinliang3; Chen, Shiyi1,2

2022-04-01

10.1063/5.0089126

PHYSICS OF FLUIDS   影响因子和分区

1070-6631

1089-7666

The contribution of various flow topologies to the subgrid-scale (SGS) flux of kinetic energy in hypersonic turbulent boundary layer for different Mach numbers and wall temperature ratios is investigated by direct numerical simulation. In the far-wall region (approximately y(+) = y/delta(nu) > 50, where y is the wall-normal location and delta(nu) is the viscous length scale), the volume fractions of flow topologies unstable focus/compressing (UFC) and stable focus/stretching (SFS) increase with the increase in filter width, resulting in the dominance of UFC and SFS in the inertial range; while in the near-wall region, the volume fractions of flow topologies unstable/saddle/saddle (UN/S/S), stable node/ saddle/saddle (SN/S/S), stable focus/compressing (SFC), and unstable focus/stretching (UFS) increase with the increase in filter width, leading to the majority of UN/S/S and SN/S/S in the inertial range. In the inertial range, the SGS flux of kinetic energy is mainly contributed by UFC and SFS far from the wall (approximately y(+) > 50) and is primarily contributed by UN/S/S and SN/S/S near the wall. The wall temperature has a significant effect on the contributions of various flow topologies in the near-wall region. As the wall temperature decreases, the contributions by SN/S/S and SFC to the SGS kinetic energy flux increase in the compression region, and those by UN/S/S and UFS increase in the expansion region. Moreover, the direct transfer of fluctuating kinetic energy from large scales to small scales is mainly characterized by UN/S/S, SFS, and SFC in the compression region, while the reverse transfer of fluctuating kinetic energy is primarily characterized by UFC, SN/S/S, and UFS in the expansion region.

SCI ; EI

英语

通讯

NSFC Basic Science Center Program[11988102] ; National Natural Science Foundation of China (NSFC)[91952104,92052301,12172161,91752201] ; Technology and Innovation Commission of Shenzhen Municipality["KQTD20180411143441009","JCYJ20170412151759222"] ; Department of Science and Technology of Guangdong Province[2019B21203001]

Mechanics ; Physics

Mechanics ; Physics, Fluids & Plasmas

WOS:000788720700024

AIP Publishing

20221712039849

Atmospheric thermodynamics ; Boundary layer flow ; Expansion ; Hypersonic boundary layers ; Hypersonic flow ; Kinetic energy ; Topology ; Turbulence ; Turbulent flow ; Volume fraction

Atmospheric Properties:443.1 ; Fluid Flow, General:631.1 ; Thermodynamics:641.1 ; Combinatorial Mathematics, Includes Graph Theory, Set Theory:921.4 ; Classical Physics; Quantum Theory; Relativity:931 ; Materials Science:951

PHYSICS

Web of Science

1.Peking Univ, State Key Lab Turbulence & Complex Syst, Coll Engn, Beijing 100871, Peoples R China
2.Southern Univ Sci & Technol, Dept Mech & Aerosp Engn, Shenzhen 518055, Peoples R China
3.Chinese Acad Sci, Inst Mech, Lab High Temp Gas Dynam, Beijing 100190, Peoples R China

Xu, Dehao,Wang, Jianchun,Yu, Changping,et al. Contribution of flow topology to the kinetic energy flux in hypersonic turbulent boundary layer[J]. PHYSICS OF FLUIDS,2022,34(4).

Xu, Dehao,Wang, Jianchun,Yu, Changping,Li, Xinliang,&Chen, Shiyi.(2022).Contribution of flow topology to the kinetic energy flux in hypersonic turbulent boundary layer.PHYSICS OF FLUIDS,34(4).

Xu, Dehao,et al."Contribution of flow topology to the kinetic energy flux in hypersonic turbulent boundary layer".PHYSICS OF FLUIDS 34.4(2022).