Self-sustained oscillations and bifurcations of transonic flow past simple airfoils

A turbulent flow past two symmetric airfoils, whose bow and aft portions are circular arcs, whereas midparts are flat, is studies numerically. The amplitude of lift coefficient oscillations versus the free-stream Mach number $\mathrm{M}_\infty$ is analyzed at zero angle of attack. Ranges of $\mathrm{M}_\infty$ in which there exist flow bifurcations are determined.