Unsteady aspects of an incident shock wave/turbulent boundary layer interaction

Humble, Raymond; Scarano, Fulvio; Oudheusden, B.W. van

doi:10.1017/s0022112009007630

Cited by 88 publications

(39 citation statements)

References 44 publications

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“…Due to the inflection point in the velocity profiles, the shear layer is unstable and large-scale vortical structures are formed, which have been observed in a number of STBLI studies (e.g. Dupont et al 2008;Humble et al 2009;Agostini et al 2012).…”

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confidence: 91%

“…Beresh, Clemens & Dolling (2002), Ganapathisubramani, Clemens & Dolling (2007, and Humble, Scarano & van Oudheusden (2009). Based on particle image velocimetry (PIV) measurements in a Mach 2 compression-ramp STBLI, Ganapathisubramani et al (2007Ganapathisubramani et al ( , 2009 observed a correlation between the shock motion and streamwise-elongated regions of low and high momentum in the incoming boundary layer.…”

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confidence: 99%

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Low-frequency dynamics in a shock-induced separated flow

et al. 2016

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The low-frequency unsteadiness in the direct numerical simulation of a Mach 2.9 shock wave/turbulent boundary layer interaction with mean flow separation is analysed using dynamic mode decomposition (DMD). The analysis is applied both to threedimensional and spanwise-averaged snapshots of the flow. The observed low-frequency DMD modes all share a common structure, characterized by perturbations along the shock, together with streamwise-elongated regions of low and high momentum that originate at the shock foot and extend into the downstream flow. A linear superposition of these modes, with dynamics governed by their corresponding DMD eigenvalues, accurately captures the unsteadiness of the shock. In addition, DMD analysis shows that the downstream regions of low and high momentum are unsteady and that their unsteadiness is linked to the unsteadiness of the shock. The observed flow structures in the downstream flow are reminiscent of Görtler-like vortices that are present in this type of flow due to an underlying centrifugal instability, suggesting a possible physical mechanism for the low-frequency unsteadiness in shock wave/turbulent boundary layer interactions.

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confidence: 99%

Low-frequency dynamics in a shock-induced separated flow

et al. 2016

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“…Most of prior scientific work on SBLI, of both experimental [2][3][4][5][6][7] and numerical nature [8][9][10][11][12][13][14], has been aimed at the case of adiabatic wall condition and many efforts have been invested in the last decade to characterize the large-scale, low-frequency unsteadiness typically found in the interaction region. This phenomenon can be particularly severe when the shock is strong enough to produce separation of the incoming boundary layer [15].…”

Section: Introductionmentioning

confidence: 99%

Heat transfer and wall temperature effects in shock wave turbulent boundary layer interactions

Bernardini¹,

Asproulias²,

Larsson³

et al. 2016

Phys. Rev. Fluids

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Direct numerical simulations are carried out to investigate the effect of the wall temperature on the behavior of oblique shock-wave/turbulent boundary layer interactions at freestream Mach number 2.28 and shock angle of the wedge generator ϕ = 8• . Five values of the wall-to-recovery-temperature ratio (Tw/Tr) are considered, corresponding to cold, adiabatic and hot wall thermal conditions. We show that the main effect of cooling is to decrease the characteristic scales of the interaction in terms of upstream influence and extent of the separation bubble. The opposite behavior is observed in the case of heating, that produces a marked dilatation of the interaction region. The distribution of the Stanton number shows that a strong amplification of the heat transfer occurs across the interaction, and the maximum values of thermal and dynamic loads are found in the case of cold wall. The analysis reveals that the fluctuating heat flux exhibits a strong intermittent behavior, characterized by scattered spots with extremely high values compared to the mean. Furthermore, the analogy between momentum and heat transfer, typical of compressible, wall-bounded, equilibrium turbulent flows does not apply for most part of the interaction domain. The pre-multiplied spectra of the wall heat flux do not show any evidence of the influence of the low-frequency shock motion, and the primary mechanism for the generation of peak heating is found to be linked with the turbulence amplification in the interaction region. * matteo.bernardini@uniroma1.it arXiv:1606.04305v1 [physics.flu-dyn]

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“…1) and is enveloped by a shear layer with negative vorticity. The shear layer has an irregular and intermittent nature which creates a fluid exchange between the outer and inner regions [33]. Moreover, a compression wave denoted by C W is formed in front of the separation bubble and exhibits an oscillation in flow evolution.…”

Section: Shock/boundary Layer Interactionmentioning

confidence: 99%

Characteristics of unsteady type IV shock/shock interaction

Chu

2012

Shock Waves

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Characteristics of the unsteady type IV shock/ shock interaction of hypersonic blunt body flows are investigated by solving the Navier-Stokes equations with highorder numerical methods. The intrinsic relations of flow structures to shear, compression, and heating processes are studied and the physical mechanisms of the unsteady flow evolution are revealed. It is found that the instantaneous surface-heating peak is caused by the fluid in the "hot spot" generated by an oscillating and deforming jet bow shock (JBS) just ahead of the body surface. The features of local shock/boundary layer interaction and vortex/boundary layer interaction are clarified. Based on the analysis of flow evolution, it is identified that the upstream-propagating compression waves are associated with the interaction of the JBS and the shear layers formed by a supersonic impinging jet, and then the interaction of the freestream bow shocks and the compression waves results in entropy and vortical waves propagating to the body surface. Further, the feedback mechanism of the inherent unsteadiness of the flow field is revealed to be related to the impinging jet. A feedback model is proposed to reliably predict the dominant frequency of flow evolution. The results obtained in this study provide physical Communicated by F. Lu. Electronic supplementary materialThe online version of this article (

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Unsteady aspects of an incident shock wave/turbulent boundary layer interaction

Cited by 88 publications

References 44 publications

Low-frequency dynamics in a shock-induced separated flow

Low-frequency dynamics in a shock-induced separated flow

Heat transfer and wall temperature effects in shock wave turbulent boundary layer interactions

Characteristics of unsteady type IV shock/shock interaction

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