Large-eddy simulation of shock-wave/turbulent boundary-layer interactions and its control using Sparkjet

Large-eddy simulations (LES) of the oblique impinging shock-wave/flat plate boundary layer interactions at Mach=2.3 and Reδ=20000 were carried out to investigate the underlying flow physics associated with flow separation and shock unsteadiness. The digital filter method was used to generate synthetic inflow turbulence without introducing any artificial low-frequency motions. The LES results were firstly well validated by comparing with the corresponding measurement data. The low-frequency characteristic of separation shock-wave was then studied by analyzing the obtained time sequence of the wall static pressure signals to realize its amplitudes, frequencies and wave-lengths. Finally, the study was extended by integrating with a control module of an active actuator “SparkJet” concept, in order to investigate its influences on the flow separation and the low-frequency motion of shock-wave unsteadiness. The analysis of flow topology and flow structure around separation region reveals that the actuator acts as a fluidic-like vortex generator, promotes the mixing process within the boundary layer, and thus largely elevates the near-wall turbulence kinetic energy level, leading to its enhanced ability to resist the flow separation. Details of the study will be presented in the final full paper