Hysteresis in flow past a NACA 0012 airfoil
The authors perform computations of two-dimensional flow past a stationary NACA 0012 airfoil with progressively increasing and decreasing angles of attack. The incompressible Reynolds averaged Navier-Stokes equations in conjunction with Baldwin-Lomax model for turbulence closure are solved using stabilized finite element formulation. Beyond a certain angle of attack the flow stalls with a sudden loss of lift and increase in drag. Hysteresis in aerodynamic coefficients is observed for a small range of attack angle close to the stall angle. This is caused by the difference in the location of separation point of the flow on the upper surface of the airfoil during increasing and decreasing angles of attack. With increasing angle, the separation point moves gradually towards the leading edge. With decreasing angle, the motion of separation point away from the leading edge is abrupt.
incompressible Reynolds averaged Navier-Stokes equations
scientific article; zbMATH DE number 1756425