Centrifugal Instabilities in a Shock-Separated Flow over a Hollow Cylinder-Flare

Priebe and Martin JFM 2012 used Direct Numerical Simulation (DNS) of a Mach 3 24 compression ramp to show that the unstable shock motion is associated with an inviscid instability. Priebe, Tu, Martin and Rowley JFM 2016 reconstructed the flowfield using Dynamic Mode Decomposition and showed a pair of counter-rotating vortical instabilities generated near separation and developing downstream. Martin, Helm and Gonzalez-Kosasky APS 2016 visualized the instability on a Mach 7 33 case. Helm and Martin JFM 2021 and PRF 2022 extended the findings to Mach 10 with Wall-Resolved Large-Eddy Simulation (WRLES), and Helm and Martin PRF 2021 explored the flow scaling using experimental, DNS and LES data. Here, we investigate the flow on a Mach 10 hollow cylinder with flare using WRLES. Spectra and low-pass filtered turbulent fields are used to identify the streamwise centrifugal instabilities. The effect of three-dimensional relaxation due to the spanwise curvature of the flare on the extent of flow separation and the strength of the centrifugal instabilities is characterized. The resulting impact on pressure and heat transfer is also presented.