We carry out experiments involving laminar shock wave/boundary layer interactions to study the emergence of three-dimensionality in a two-dimensional compression ramp setup. The experiments demonstrate that deviation from the laminar two-dimensional behavior appears due to coherent three-dimensional structures. These structures result in the formation of regular streamwise streaks after reattachment and counter-rotating cells in the bubble. Furthermore, these effects amplify with Reynolds numbers as well as through upstream disturbances from distributed random roughness. To investigate the emergence of specific spanwise length scales, we carry out an input-output analysis which quantifies the amplification of exogenous disturbances. Our analysis of the two-dimensional flow reveals that the streaks arise from a preferential amplification of upstream counter-rotating vortical perturbations with a specific spanwise wavelength. These observations are in good agreement with experiments and are verified by carrying out direct numerical simulations.
|Original language||English (US)|
|Title of host publication||AIAA AVIATION 2020 FORUM|
|Publisher||American Institute of Aeronautics and Astronautics Inc, AIAA|
|State||Published - 2020|
|Event||AIAA AVIATION 2020 FORUM - Virtual, Online|
Duration: Jun 15 2020 → Jun 19 2020
|Name||AIAA AVIATION 2020 FORUM|
|Conference||AIAA AVIATION 2020 FORUM|
|Period||6/15/20 → 6/19/20|
Bibliographical noteFunding Information:
Financial support from the Office of Naval Research (under award N00014-19-1-2037) is gratefully acknowledged. This work is also supported in part by the Army Futures Command, Army Research Laboratory Grant W911NF1920243.