Post-shock turbulence recovery in oblique-shock/turbulent boundary layer interaction flows

Yu, Ming; Dong, Siwei; Liu, Peng Xin; Tang, Zhigong; Yuan, Xianxu; Xu, Chun-Xiao

doi:10.1017/jfm.2023.212

Cited by 5 publications

(5 citation statements)

References 75 publications

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“…This is probably due to two counteracting effects: one is the increment of the friction Reynolds number in the streamwise direction (figure 3), and the other is the weakening of the VLSMs, similar to the observations in the recovery downstream of the shock/TBL interactions (Yu et al. 2023).…”

Section: Local Turbulence Statisticssupporting

confidence: 77%

“…In the study of Yu et al. (2023) that discussed the negative during the turbulence recovery downstream of the shock/TBL interactions, incompatible growth rates were found between the nominal and kinetic energy thicknesses, with the former much higher than the latter, suggesting that the kinetic energy dissipation per unit length is lowered. This is also the case for the presently considered TBL in the WSP and its neighbourhood (omitted for brevity), in that the ratio between the kinetic energy thickness and the nominal thickness is lower as it approaches downstream.…”

Section: Local Turbulence Statisticsmentioning

confidence: 97%

“…Following Yu et al. (2023), the mean velocity is split as in which the van Driest transformation of the canonical mean velocity is constructed as the universal mean velocity profile proposed by Subrahmanyam, Cantwell & Alonso (2022), with the mixing length model introduced by Cantwell (2019). Similarly, the mean total stress can be decomposed as where and denote the viscous and Reynolds shear stresses, respectively.…”

Section: Local Turbulence Statisticsmentioning

confidence: 99%

“…For example, Yu et al. (2023) found that is the dominant contributor of near the shock/TBL interaction zone, and its ratio to decreases steadily as the embedded shear layer weakens. Moreover, Yoon, Hwang & Sung (2018), from another perspective, found that the enhanced large-scale structures in an APG-TBL () have a considerable contribution to the skin friction through the superposition and amplitude modulation effects on the vortical motions, consistent with our results even though the enhanced large-scale structures herein are not induced by APG.…”

Section: Local Turbulence Statisticsmentioning

confidence: 99%

See 3 more Smart Citations

Hypersonic turbulent boundary layer over the windward side of a lifting body

Dong,

Yu,

Tong

et al. 2024

J. Fluid Mech.

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In the present study, we performed direct numerical simulations for a hypersonic turbulent boundary layer over the windward side of a lifting body, the HyTRV model, at Mach number $6$ and attack angle 2 $^{\circ }$ to investigate the global and local turbulent features, and evaluate its difference from canonical turbulent boundary layers. By scrutinizing the instantaneous and averaged flow fields, we found that the transverse curvature on the windward side of the HyTRV model induces the transverse opposing pressure gradients that push the flow on both sides towards the windward symmetry plane, yielding significant effects of the azimuthal inhomogeneity and large-scale cross-stream circulations, moderate and azimuthal independent influences of adverse pressure gradient, and negligible impact of the mean flow three-dimensionality. Further inspecting the local turbulent statistics, we identified that the mean and fluctuating velocity become increasingly similar to the highly decelerated turbulent boundary layers over flat plates in that the mean velocity deficit is enhanced, and the outer layer Reynolds stresses are amplified as it approaches the windward symmetry plane, and prove to be self-similar under the scaling of Wei & Knopp (J. Fluid Mech., vol. 958, 2023, A9) for adverse-pressure-gradient turbulent boundary layers. Conditionally averaged Reynolds stresses based on strong sweeping and ejection events demonstrated that the Kelvin–Helmholtz instability of the strong embedded shear layer induced by the large-scale cross-stream circulations is responsible for the turbulence amplification in the outer layer. The strong Reynolds analogy that relates the mean velocity and temperature was refined to incorporate the non-canonical effects, showing considerable improvements in the accuracy of such a formula. On the other hand, the temperature fluctuations are still transported passively, as indicated by their resemblance to the velocity. The conclusions obtained in the present study provide potentially profitable information for turbulent modelling modification for the accurate predictions of skin friction and wall heat transfer.

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Section: Local Turbulence Statisticssupporting

confidence: 77%

Section: Local Turbulence Statisticsmentioning

confidence: 97%

Section: Local Turbulence Statisticsmentioning

confidence: 99%

Section: Local Turbulence Statisticsmentioning

confidence: 99%

See 2 more Smart Citations

Hypersonic turbulent boundary layer over the windward side of a lifting body

Dong,

Yu,

Tong

et al. 2024

J. Fluid Mech.

Self Cite

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show abstract

“…Li et al (2019) extended this method to compressible flow and investigated the influence of density and viscosity on the skin friction of the supersonic turbulent channel and zero-pressure-gradient turbulent boundary layers (Fan, Li & Pirozzoli 2019). Yu et al (2023) performed DNS of impinging SWTBLIs at Mach 2.28 and applied the RD method to analyse the generation mechanism of C f . Their results indicated that, in the upstream boundary layer, C f was mainly contributed by mean viscous dissipation and TKE production; as the flow entered the interaction zone, the contribution from the advection term was also significantly enhanced.…”

Section: Introductionmentioning

confidence: 99%

Wall skin friction analysis in a hypersonic turbulent boundary layer over a compression ramp

Guo,

Zhang,

Zhu

et al. 2024

J. Fluid Mech.

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In this paper, direct numerical simulations in hypersonic turbulent boundary layers over a $24^{\circ }$ compression ramp at Mach 6.0 are performed. The wall skin friction and its spanwise non-homogeneity in the interaction region are analysed via the spectral analysis and drag decomposition method. On the compression ramp, the premultiplied spanwise energy spectrum of wall shear stress $\tau _{w}$ reveals two energetic spanwise length scales. One occurs in the region of $x/\delta _{ref}=0\unicode{x2013}3$ ( $x=0$ lies in the compression corner; $\delta _{ref}$ is the boundary layer thickness upstream of the interaction region) and is consistent with that of the large-scale streamwise vortices, indicating that the fluctuation intensity of $\tau _{w}$ is associated with the Görtler-type structures. The other one is observed downstream of $x/\delta _{ref}=3.0$ and corresponds to the regenerated elongated streaky structures. The fluctuation intensity of $\tau _{w}$ peaks at $x/\delta _{ref}=3.0$ , where both the above energetic length scales are observed. The drag decomposition method proposed by Li et al. (J. Fluid Mech., vol. 875, 2019, pp. 101–123) is extended to include the effects of spanwise non-homogeneity so that it can be used in the interaction region where the mean flow field and the mean skin friction $C_f$ exhibit an obvious spanwise heterogeneity. The results reveal that, in the upstream turbulent boundary layer, the drag contribution arising from the spanwise heterogeneity can be neglected, while this value on the compression ramp is up to 20.7 % of $C_f$ , resulting from the Görtler-type vortices. With the aid of the drag decomposition method, it is found that the main flow features that contribute positively to the amplification of $C_f$ and its rapid increase on the compression ramp includes: the density increase across the shock, the high mean shear stress and turbulence amplification around the detached shear layer and the Favre-averaged downward velocity towards the ramp wall. Compared with the spanwise-averaged value, $C_f$ and its components at the spanwise station where the downwash and upwash of the Görtler-type vortices occur reveal a spanwise variation exceeding 10 %.

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Coherent structures and turbulent model refinement in oblique shock/hypersonic turbulent boundary layer interactions

Yu,

Sun,

Zhou

et al. 2023

Physics of Fluids

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In the present study, we investigate the evolution of turbulent statistics and coherent structures in hypersonic turbulent boundary layers at the Mach number of 5 impinged by oblique shock waves generated by the wedge with the angles of 14°, 10°, and 6°, inducing strong, mild, and incipient flow separation, by exploiting direct numerical simulation databases, for the purpose of revealing the underlying flow physics that are of significance to turbulent modeling. We found that the large-scale structures are amplified within the interaction zone, manifested in the form of large-scale low- and high-speed streaks with the spanwise length scale of boundary layer thickness, and gradually decay downstream, the process of which is extremely long. The abrupt variation in the characteristic length, time, and velocity scales as well as the incompatible viscous dissipation of the mean and turbulent kinetic energy results in the incorrect predictions by the Reynolds-Averaged Navier–Stokes (RANS) equation simulations, provided the models are established based on solving the transport equations of the turbulent kinetic equation and its viscous dissipation (k−ε or k−ω models, for instance). To amend this issue, we propose to refine the parameters in the model as the functions of wall pressure, the flow quantities related to multiple flow features. The RANS simulations with the k−ω SST model utilizing the proposed refinement improve greatly the accuracy of the skin friction, wall heat flux, and Reynolds shear stress downstream of the interaction zone, and the wall pressure distributions in hypersonic turbulence over compression ramp, suggesting its promising prospect in engineering applications.

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Post-shock turbulence recovery in oblique-shock/turbulent boundary layer interaction flows

Cited by 5 publications

References 75 publications

Hypersonic turbulent boundary layer over the windward side of a lifting body

Hypersonic turbulent boundary layer over the windward side of a lifting body

Wall skin friction analysis in a hypersonic turbulent boundary layer over a compression ramp

Coherent structures and turbulent model refinement in oblique shock/hypersonic turbulent boundary layer interactions

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