Correlation Analysis Between Low-Frequency Shock Oscillation and Liutex in SBLI

The overarching objective of the study is to investigate what the driven source of flow frequency unsteadiness of Shock Wave Boundary Layer Interaction (SBLI) is as it is still unknown after several decades of intensive research. The tool is to use high order Large Eddy Simulation (LES) with a large grid system to study the correlation between SBLI low frequencies and vortices motion. Newly developed third-generation vortex definition/visualization method—Liutex was adopted in this study to investigate the motion of complex vortex structure in the supersonic boundary layer separation and the correlation between low-frequency shock oscillation and Liutex. From the power spectrum analysis, it clearly shows that the pressure fluctuation is closely related to Liutex. The low frequencies of pressure fluctuation (low-frequency noise) are highly consistent with Liutex frequencies.