STABILITY ANALYSIS OF A COMPRESSIBLE TURBULENT FLOW OVER A BACKWARD-FACING STEP etc15 Tracking Number 397Presentation: Session: Instability and Transition 5 Room: Room A Session start: 10:30 Thu 27 Aug 2015 Samir Beneddine samir.beneddine@onera.fr Affifliation: ONERA Emerick Bodere emerick.bodere@u-psud.fr Affifliation: Denis Sipp denis.sipp@onera.fr Affifliation: ONERA Topics: - Instability and transition Abstract: In this study we focus on the stability analysis of a compressible turbulent flow over a closed backward-facing step. To perform the stability analysis, we have computed a mean-flow from an unsteady 3D simulation. This analysis reveals a completely stable spectrum, with some global modes exhibiting a frequency close to the peaks of the frequency spectrum of the unstead 3D simulation. Since none of the modes are unstable, we have then performed a singular value decomposition that allows to see the optimal gain response of the flow at each frequency. This final study reveals several particular frequencies that match what is observed in the unsteady simulation. |