Bifurcations of Transonic Flow Past Flattened Airfoils

Alexander Kuzmin (1)

1 Laboratory of Aerodynamics

We study numerically turbulent flow past a simple symmetric airfoil with a flat midpart and flow past the asymmetric J-78 airfoil designed by A. Jameson. The study is focused on freestream conditions in which there exist: (*) bifurcations of the entire flow structure, (**) buffet onset caused by instability of the shock-induced boundary layer separation. For the symmetric airfoil, computations show both bifurcations and buffet onset in a range of the freestream Mach number. For the J-78 airfoil with a small curvature of the upper surface, instabilities of the flow structure occur at negative angles of attack.

Keywords: Local supersonic regions; instability; bifurcations

Domains: Fluids mechanics [physics.class-ph]; Fluid mechanics [physics.class-ph]

Alexander Kuzmin. Bifurcations of Transonic Flow Past Flattened Airfoils. 2008. ⟨hal-00433168⟩