Other Respects on SBLI Controls

An implicit Large Eddy Simulation (ILES) is carried out for a Micro Vortex Generator (MVG) controlled supersonic ramp flow at Ma = 2.5 and Re = 5760 based on inflow momentum boundary thickness. The results are validated against the TU Delft experiment on the same MVG geometry and Mach number. Several techniques are used to analyze the coherent structures in the MVG wake. The vortex system in the MVG wake is visualized using vortex identification method and it is found that two primary counter rotating streamwise vortex pair are induced by the MVG, which would further lead to a trail of vortex rings through K-H instability. The average distance between adjacent vortex rings is determined by a spatial auto-correlation of vorticity, which is estimated as 1.5 MVG height. Two dimensionality reduction algorithms, namely Proper Orthogonal Decomposition (POD), and Dynamic Mode Decomposition (DMD) are applied to a set of flow field sequences on the spanwise symmetry plane. POD modes identify structures containing most of the turbulent kinetic energy and DMD modes, capturing single frequency structures which are most essential to the unsteady dynamics.

Keywords: Dynamic Mode Decomposition (DMD), Modes Analysis, MVG, Proper Orthogonal Decomposition (POD).