Some physical aspects of shock wave/boundary layer interactions

Délery, Jean; Dussauge, Jean‐Paul

doi:10.1007/s00193-009-0220-z

Cited by 187 publications

(87 citation statements)

References 27 publications

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“…The error was calculated to be 1.8% from the baseline value. For both locations, the comparison between the baseline case (clean tunnel) and the cases with micro-ramps shows that the presence of micro-ramp proved to delay the pressure rise caused by the impinging shock or in other words managed to reduce the upstream interaction length as mentioned by Delery [1] and Delery et al [24]. Note that X s is the location of shock impingement as described in Section 2.6 and is represented by X = 0 in Figure 16.…”

Section: Resultsmentioning

confidence: 81%

Micro-Ramps for Hypersonic Flow Control

et al. 2012

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Shock/boundary layer interaction (SBLI) is an undesirable phenomenon, occurring in high-speed propulsion systems. The conventional method to manipulate and control SBLI is using a bleed system that involves the removal of a certain amount of mass of the inlet flow to control boundary layer separation. However, the system requires a larger nacelle to compensate the mass loss, larger nacelles contribute to additional weight and drag and reduce the overall performance. This study investigates a novel type of flow control device called micro-ramps, a part of the micro vortex generators (VGs) family that intends to replace the bleed technique. Micro-ramps produce pairs of counter-rotating streamwise vortices, which help to suppress SBLI and reduce the chances of flow separation. Experiments were done at Mach 5 with two micro-ramp models of different sizes. Schlieren photography, surface flow visualization and infrared thermography were used in this investigation. The results revealed the detailed flow characteristics of the micro-ramp, such as the primary and secondary vortices. This helps us to understand the overall flow physics of micro-ramps in hypersonic flow and their application for SBLI control.

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Section: Resultsmentioning

confidence: 81%

Micro-Ramps for Hypersonic Flow Control

et al. 2012

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“…Such interactions form a complex dynamical system with a broad range of temporal and spatial scales. Unsteady pressure and friction forces may couple to resonant frequencies of the structure and may result in failure due to fatigue (Dolling 2001;Délery & Dussauge 2009). Of particular interest is the low-frequency unsteadiness of the reflected shock observed in SWBLI with mean boundary-layer separation.…”

Section: Introductionmentioning

confidence: 99%

Unsteady effects of strong shock-wave/boundary-layer interaction at high Reynolds number

2017

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We analyse the low-frequency dynamics of a high-Reynolds-number impinging shockwave/turbulent boundary-layer interaction (SWBLI) with strong mean-flow separation. The flow configuration for our grid-converged large-eddy simulations (LES) reproduces recent experiments for the interaction of a Mach 3 turbulent boundary layer with an impinging shock that nominally deflects the incoming flow by 19.6○ . The Reynolds number based on the incoming boundary layer thickness of Re δ0 ≈ 203 ⋅ 10 3 is considerably higher than in previous LES studies. The very long integration time of 3805 δ 0 U 0 allows for an accurate analysis of low-frequency unsteady effects. Experimental wallpressure measurements are in good agreement with the LES data. Both datasets exhibit the distinct plateau within the separated-flow region of a strong SWBLI. The filtered three-dimensional flow field shows clear evidence of counter-rotating streamwise vortices originating in the proximity of the bubble apex. Contrary to previous numerical results on compression ramp configurations, these Görtler-like vortices are not fixed at a specific spanwise position, but rather undergo a slow motion coupled to the separationbubble dynamics. Consistent with experimental data, power spectral densities (PSD) of wall-pressure probes exhibit a broadband and very energetic low-frequency component associated with the separation-shock unsteadiness. Sparsity-promoting dynamic mode decompositions (SPDMD) for both spanwise-averaged data and wall-plane snapshots yield a classical and well-known low-frequency breathing mode of the separation bubble, as well as a medium-frequency shedding mode responsible for reflected and reattachment shock corrugation. SPDMD of the two-dimensional skin-friction coefficient further identify streamwise streaks at low frequencies that cause large-scale flapping of the reattachment line. The PSD and SPDMD results of our impinging SWBLI support the theory that an intrinsic mechanism of the interaction zone is responsible for the lowfrequency unsteadiness, in which Görtler-like vortices might be seen as a continuous (coherent) forcing for strong SWBLI.

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“…Shock-wave/boundary-layer interactions (SWBLIs) have been widely studied in the past few decades: see for example the review papers of Délery & Marvin (1986), Viswanath (1988), Dolling (2001), Smits & Dussauge (2006), Clemens & Narayanaswamy (2009) and Délery & Dussauge (2009). The most commonly considered interactions concern those with a turbulent boundary layer, although laminar or transitional interactions have also been investigated in the literature.…”

Section: Introductionmentioning

confidence: 99%

A scaling analysis for turbulent shock-wave/boundary-layer interactions

Souverein¹,

Bakker²,

Dupont³

2013

J. Fluid Mech.

119

108

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A model based on mass conservation properties is developed for shock-wave/boundarylayer interactions (SWBLIs), aimed at reconciling the observed great diversity in flow organization documented in the literature, induced by variations in interaction geometry and aerodynamic conditions. It is the basis for a scaling approach for the interaction length that is valid independent of the geometry of the flow (considering compression corners and incident-reflecting shock interactions). As part of the analysis, a scaling argument is proposed for the imposed pressure jump that depends principally on the free-stream Mach number and the flow deflection angle. Its interpretation as a separation criterion leads to a successful classification of the separation states for turbulent SWBLIs (attached, incipient or separated). In addition, the dependence of the interaction length on the Reynolds number and the Mach numbers is accounted for. A large compilation of available data provides support for the validity of the model. Some general properties on the state of the flow are derived, independent of the geometry of the flow and for a wide range of Mach numbers and Reynolds numbers.

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Some physical aspects of shock wave/boundary layer interactions

Cited by 187 publications

References 27 publications

Micro-Ramps for Hypersonic Flow Control

Micro-Ramps for Hypersonic Flow Control

Unsteady effects of strong shock-wave/boundary-layer interaction at high Reynolds number

A scaling analysis for turbulent shock-wave/boundary-layer interactions

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