Shock Wave Boundary Layer Interaction Unsteadiness: The Effects of Configuration and Strength

Threadgill, James A.; Bruce, Paul J.

doi:10.2514/6.2016-0077

Cited by 13 publications

(16 citation statements)

References 29 publications

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“…A study by Threadgill & Bruce (2016) was performed in the same wind tunnel at the same free-stream conditions. In the study, the evolution of the boundary layer profile was characterised from ≈95 to 45 mm upstream of the AR eff = 1.00 inviscid shock impingement point.…”

Section: Regular-irregular Transitionmentioning

confidence: 99%

Confinement effects on regular–irregular transition in shock-wave–boundary-layer interactions

Grossman

Bruce

2018

J. Fluid Mech.

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An oblique shock wave is generated in a Mach 2 flow at a flow deflection angle of 12• . The resulting shock-wave-boundary-layer interaction (SWBLI) at the tunnel wall is observed. A novel traversable shock generator allows the position of the SWBLI to be varied relative to a downstream expansion fan. The relationship between the SWBLI, the expansion fan and the wind tunnel arrangement is studied. Schlieren photography, surface oil flow visualisation, particle image velocimetry and high-spatial-resolution wall pressure measurements are used to investigate the flow. It is observed that stream-normal movement of the shock generator downwards (towards the floor and hence the point of shock reflection) is accompanied by (1) growth in the streamwise extent of the shock-induced boundary layer separation, (2) upstream movement of the shock-induced separation point while the reattachment point remains nearly fixed, (3) an increase in separation shock strength and (4) transition between regular and irregular (Mach) reflection without an increase in incident shock strength. The role of free interaction theory in defining the separation shock angle is considered and shown to be consistent with the present measurements over a short streamwise extent. An SWBLI representation is proposed and reasoned which explains the apparent increase in separation shock strength that occurs without an increase in incident shock strength.

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Section: Regular-irregular Transitionmentioning

confidence: 99%

Confinement effects on regular–irregular transition in shock-wave–boundary-layer interactions

Grossman

Bruce

2018

J. Fluid Mech.

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“…According to the published researches, [33][34][35] the incipience and scale of the oblique shock-induced turbulent boundary layer separation is mainly determined by the shock caused static pressure ratio. Since the effect of shock/boundary layer interaction is neglected in the cases with the existence of the reflected shock, a limitation for the normal component of first passage shock upstream Mach number, which determines the static pressure ratio, could be set to prevent arising of the large-scale shock-induced boundary layer separation, i.e.…”

Section: S1mentioning

confidence: 99%

A new method for rapid shock loss evaluation and reduction for the optimization design of a supersonic compressor cascade

Liu

Shi

2017

Proceedings of the Institution of Mechanical Engineers, Part G:

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A one-dimensional analytical shock loss prediction method was proposed to tailor the shock system, i.e. the strength of the first and second passage shock, and reduce the shock loss in a supersonic cascade. To develop the one-dimensional analytical model, the shock system in a supersonic cascade was divided into four processes which can be seen in most supersonic compressor cascade, i.e. the flow upstream the extending-external shock, the flow between the extendingexternal shock and the first passage shock, the accelerating flow from the first passage shock to the second passage shock, and the flow downstream of the second passage shock. Based on some flow assumptions and experimental empirical correlations, the complex flows, containing the shock system, in the blade passage of a supersonic compressor cascade could be described with one-dimensional relationships, which can be used to predict shock losses along the flow passage rapidly and determine the shock system improving direction for achieving lower shock loss while keeping the same cascade static pressure ratio. In order to validate the one-dimensional analytical method, the shock system of two supersonic cascades ARL-SL19 and DLR-PAV-1.5 are modified based on the analysis of the model. The modified cascades achieved about 29% and 25% reduction of shock loss at redesign point compared with baseline cascades, respectively.

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“…The simulation set‐up is based on the LES computation of Morgan et al 52 and the experiment of Threadgill and Bruce 53 . The inflow Mach number is chosen to be

Ma=2.0

.…”

Section: Three‐dimensional Oblique Shock‐wave/turbulent Boundary‐laye...mentioning

confidence: 99%

“…However, due to the slightly bigger Mach number of

2.05

and the different boundary layer properties in the reference LES, we don't expect a fully quantitative agreement with the results of Morgan et al, 52 but the same trends of the wall pressure and skin‐friction coefficient curves. The experiment of Threadgill and Bruce 53 has higher Reynolds numbers and the 3D sidewall effects of the wind tunnels, but the same Mach number and the same shock strength are utilized so that it is used for a supplementary validation by comparing with the dimensionless Strouhal number of the flow unsteadiness. Table 1 summarizes the characteristic properties of our flow conditions.…”

Section: Three‐dimensional Oblique Shock‐wave/turbulent Boundary‐laye...mentioning

confidence: 99%

On the investigation of oblique shock‐wave/turbulent boundary‐layer interactions with a high‐order discontinuous Galerkin method

Gao

Kuhn

Munz

2022

Numerical Methods in Fluids

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Shock-wave/turbulent boundary-layer interactions are still a challenge for numerical simulation. The shock capturing needs dissipation to avoid spurious oscillations while turbulence will be falsified by introducing dissipation. Especially, an accurate prediction of quantities such as the skin-friction coefficient inside the interaction area of shock wave and turbulent flow is a critical point.In this article, we investigate a wall-resolved large eddy simulation of oblique shock-wave/turbulent boundary-layer interactions by a high-order discontinuous Galerkin scheme. The high-order scheme handles the turbulent flow very well. The shock-capturing is confined to the near shock region by switching locally to a finite volume second-order TVD scheme on subcells. This strategy is completed with the application of a shock indicator to a filtered flow field.A global spanwise filter is applied to avoid switching on the shock-capturing procedure in regions of under-resolved turbulent structures. We validate our numerical results first at shock-wave/laminar boundary-layer interaction. The main simulation under consideration is a Mach 2 turbulent boundary-layer with an inlet momentum-thickness Reynolds number of 1628, interacting with an oblique shock that deflects the incoming flow by 8 • . We employ a reformulated synthetic eddy method at the inlet to avoid the influence of recycling-based turbulence generating schemes on the low-frequency unsteadiness. The anisotropic linear forcing technique is adopted to further reduce the turbulence recovery length. Through the spectral analysis of wall pressure probes, a typical Strouhal number of around 0.03 is observed. We attribute the discrepancies between an experimental scaling law and our computation to the three-dimensional sidewall effects in the experiment. With the assistance of numerical results from this article and other authors, a new scaling law for the spanwise-periodic computations is suggested to quantify the difference between experimental and computed data.

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Shock Wave Boundary Layer Interaction Unsteadiness: The Effects of Configuration and Strength

Cited by 13 publications

References 29 publications

Confinement effects on regular–irregular transition in shock-wave–boundary-layer interactions

Confinement effects on regular–irregular transition in shock-wave–boundary-layer interactions

A new method for rapid shock loss evaluation and reduction for the optimization design of a supersonic compressor cascade

On the investigation of oblique shock‐wave/turbulent boundary‐layer interactions with a high‐order discontinuous Galerkin method

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