Shock Wave Laminar Boundary Layer Interaction Research Articles

On the Behaviour of High-Order One-Step Monotonicity-Preserving Scheme for Direct Numerical Simulation of Shocked Turbulent Flows

The objective of this paper is to check the ability of the high-order OSMP scheme [Daru, V., and C. Tenaud. 2004. “HighOrder One-Step Monotonicity-Preserving Schemes for Unsteady Compressible Flow Calculations.” Journal of Computational Physics 193 (2): 563–594] to accurately compute turbulent compressible flows with a special focus on the effect of the MP constraints on solutions of wall bounded turbulent shocked flows. We first validate numerical approaches on two canonical test cases: the 3D Taylor-Green vortex and the steady 2D shock-wave laminar boundary layer interaction. The emblematic case where a shock wave interacts with a turbulent boundary layer is then simulated. We conclude that the OSMP scheme coupled with a centred 2nd-order approximation for the diffusive fluxes constitutes a reliable numerical tool for the DNS of compressible turbulent shocked flows, that is completely competitive compared to other approaches since the overall errors are lowered of about one order of magnitude for the same grid resolution.

Effective plasma buffet and drag control for laminar transonic aerofoil

The effect of plasma actuators on shock wave–laminar boundary layer interaction was studied experimentally on transonic laminar aerofoil. The unsteady characteristics of the separation zone including the transonic buffet were measured. Two kinds of electrical discharge actuators were used for the flow control. Successful suppression of separated flow and laminar transonic buffet by plasma actuators was demonstrated. An analysis of the effect of power and frequency of the discharge on shock wave–laminar boundary layer interaction was carried out. High efficiency ratio of the separation control by plasma actuators was achieved in the experiments.

Suppression of a laminar separation by a spark discharge at a supersonic Mach number

The paper deals with control the shock wave / laminar boundary layer interaction (SWBLI) by a spark discharge. Incident shock wave generated by a wedge induced the separation of the boundary layer developed on the flat plate at M=1.43. The inflow boundary layer state was laminar. The quantitative measurements were performed by PIV. It was found that a turbulent spot generated by a spark discharge suppresses the separation zone. But the thermal spot increases the loss of total pressure in the boundary layer. The effect of the discharge power on the zone of SWBLI has been studied.

Use of Weno Schemes for Simulation of the Reflected Shock Wave–Boundary Layer Interaction

Numerical simulation of the shock wave–laminar boundary layer interaction is carried out on the basis of the model problem at different Reynolds numbers. The use of WENO schemes of high order of accuracy is demonstrated. The calculated shock-wave structure of the fl ow is compared with the data available in the literature and with the data obtained from TVD schemes. Criteria of accuracy of numerical calculations that are related to the position of shock-wave structures, and also the time of solution of the problem with various difference schemes, are discussed. Recommendations on practical use of difference schemes of high order of accuracy are given.

Bifurcations in shock-wave/laminar-boundary-layer interaction: global instability approach

The principal objective of this paper is to study some unsteady characteristics of an interaction between an incident oblique shock wave impinging on a laminar boundary layer developing on a flat plate. More precisely, this paper shows that some unsteadiness, in particular the low-frequency unsteadiness, originates in a supercritical Hopf bifurcation related to the dynamics of the separated boundary layer. Various direct numerical simulations were carried out of a shock-wave/laminar-boundary-layer interaction (SWBLI). Three-dimensional unsteady Navier–Stokes equations are numerically solved with an implicit dual time stepping for the temporal algorithm and high-order AUSMPW+ scheme for the spatial discretization. A parametric study on the oblique shock-wave angle has been performed to characterize the unsteady behaviour onset. These numerical simulations have shown that starting from the incident shock angle and the spanwise extension, the flow becomes three-dimensional and unsteady. A linearized global stability analysis is carried out in order to specify and to find some characteristics observed in the direct numerical simulation. This stability analysis permits us to show that the physical origin generating the three-dimensional characters of the flow results from the existence of a three-dimensional stationary global instability.

3D Steady and Unsteady Bifurcations in a Shock-wave/Laminar Boundary Layer Interaction: A Numerical Study

The principal objective of this paper is to study some unsteady characteristics of an interaction between an incident oblique shock wave impinging a laminar boundary layer developing on a plate plane. More precisely, this paper shows that some unsteadiness, in particular the low frequency unsteadiness, originate in a supercritical Hopf bifurcation related to the dynamics of the separated boundary layer and not necessarily to the coherent structures resulting from the turbulent character of the boundary layer crossing the shock wave. Numerical computations of a shock-wave/laminar boundary-layer interaction (SWBLI) have been compared with a classical test case (Degrez test case) and both two-dimensional and three-dimensional (3D) unsteady Navier–Stokes equations are numerically solved with an implicit dual time stepping for the temporal algorithm and high order AUSM+ scheme for the spatial discretization. A parametric study on the oblique shock-wave angle has been performed to characterize the unsteady behaviour onset. Finally, discussions and assumptions are made about the origin of the 3D low frequency unsteadiness.

Shock-wave laminar boundary-layer interaction in supercritical transonic flow

The interaction between an oblique shock wave and a laminar boundary layer in a supercritical transonic flow is studied numerically for shock strengths sufficiently large that separation occurs. Of particular interest is the behavior of the solution as the shock strength parameter is increased towards an order one value. It is found that the separation and reattachment regions tend to become distinct, with an intervening plateau region of nearly constant pressure, as the shock strength increases. A possible limit structure for order one shock strengths is also suggested.

Interaction onde de choc-couche limite laminaire sur un corps de revolution en rotation

(Shock Wave-Laminar Boundary Layer Interaction on a Spinning Axisymmetric Body)—A method is developed to predict the shock wave-laminar boundary layer interaction on an axisymmetric body spinning in axial flow. The integral scheme of Lees, Reeves and Klineberg is used. The Falkner Skan “type” equations is then established for the boundary layer on spinning cylinder and used to construct the polynomial representation of the integral quantities. The independence of the polynomials with respect to the spinning rate is demonstrated. A cylinder of 200 mm diameter with a flare is built and tested up to 5000 rmp in wind tunnel at M = 2.21. The pressure measurements are in good agreement with the theoretical results. The rotation induces the decreasing of the pressure level and boundary layer separation inside the interaction region.

Modified Crocco-Lees Mixing Theory for Supersonic Separated and Reattaching Flows

Re-examination of the Crocco-Lees method has shown that the previous quantitative disagreement between theory and experiment in the region of flow up to separation was caused primarily by the improper C(K) relation assumed. A new C(K) correlation, based on low-speed theoretical and experimental data and on supersonic experimental results, has been developed and found to be satisfactory for accurate calculation of two-dimensional laminar super sonic flows up to separation. A study of separated and reattaching regions of flow has led to a physical model which incorporates the concept of the dividing streamline and the results of experiment. According to this physical model, viscous momentum transport is the essential mechanism in the zone between separation and the beginning of reattachment, while the reattachment process is, on the contrary, an essentially inviscid process. This physical model has been translated into Crocco-Lees language using a semi-empirical approach, and approximate C(K) and F(K) relations have been determined for the separated and reattaching regions. The results of this analysis have been applied to the problem of shock wave-laminar boundary layer interaction, and satisfactory quantitative agreement with experiment has been achieved.