Investigating the flow field dynamics of transonic shock buffet using particle image velocimetry

Abstract An experimental investigation was performed in order to better understand the transonic shock buffet phenomenon and determine dominant flow interactions at specific conditions. A rigid wing shape of an OAT15A airfoil placed Trisonic Wind Tunnel Munich, where both Mach number angle attack were varied between $$0.65< M_\infty < 0.77$$ 0.65 < M ? 0.77 $$3.8< \alpha 6.3^\circ$$ 3.8 ? 6 . 3 ? respectively. With use high-speed imaging, high-quality optics state-of-the-art laser equipment, highly resolved velocity field measurements obtained via particle image velocimetry, streamwise vertical components computed over suction side center plane. It shown that sustained first occurs $$M_\infty \ge 0.74$$ ? 0.74 when maintaining constant $$\alpha =5.8^\circ$$ = 5 8 . Similarly, increase $$\alpha$$ for a fixed =0.74$$ also led development buffet. Instantaneous snapshots confirmed presence recirculation region downstream moving shock, wake size located most upstream. Streamwise correlations near airfoil’s upper surface extract characteristic convective structures. The appeared with distance, ranging on average 50 150 m/s. Overall, these time-resolved allow dynamics during highlight independent effect this complex phenomenon.