Understanding transition mechanisms in high speed boundary layers is important for predictive design and control in aeronautics. Shock boundary layer interaction, in which the inviscid pressure rise causes the incoming boundary layer to separate and reattach downstream, has a destabilizing effect on the flow. The presence of a recirculation bubble and highly concave curvature of the streamlines near reattachment can support large growth of perturbations. In this paper, we investigate the receptivity properties of an asymptotically stable shock boundary layer interaction on a slender double wedge. The optimal frequency response of the two-dimensional steady state flow subjected to external perturbations is computed. It is found that the flow is highly receptive to low-frequency streamwise vorticity perturbations of a specific spanwise wavelength in the incoming boundary layer. This results in growth of streaks post-reattachment. The most amplified spanwise wavelength scales with approximately twice the boundary layer thickness at reattachment. By excluding the role of bubble dynamics in the input-output analysis, we find that recirculation bubble plays an important role in the perturbation growth and the spanwise wavelength selection. The present work demonstrates the efficacy of input-output analysis for investigating the stability and sensitivity of compressible boundary layer flows.
|Original language||English (US)|
|Title of host publication||2018 Fluid Dynamics Conference|
|Publisher||American Institute of Aeronautics and Astronautics Inc, AIAA|
|State||Published - 2018|
|Event||48th AIAA Fluid Dynamics Conference, 2018 - Atlanta, United States|
Duration: Jun 25 2018 → Jun 29 2018
|Name||2018 Fluid Dynamics Conference|
|Other||48th AIAA Fluid Dynamics Conference, 2018|
|Period||6/25/18 → 6/29/18|
Bibliographical noteFunding Information:
The authors would like to acknowledge the help from Mr. Anthony Knutson in grid construction. This work was sponsored by Air Force Office of Scientific Research under grant number FA9550-12-1-0064 and the Office of Naval Research under grant number N00014-15-1-2522. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the funding agencies or the U.S. Government.
© 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.