Numerical study of buffet and transonic flutter on the NLR 7301 airfoil

Intensive numerical calculations have been carried out on the NLR 7301 supercritical airfoil section under transonic flow conditions. The airfoil is assumed to be suspended in a two degree of freedom aero elastic system allowing the airfoil to move in both pitching and plunging modes respectively. The numerical code used for the present investigation is a two-dimensional time accurate Navier–Stokes solver based on the full equations. The Spalart–Allmaras turbulence model has been used throughout the calculations. astic constraints, mass ratio, etc. have been taken from frequent tests in the DLR-DNW transonic wind tunnel carried out by the DLR Institute of Aeroelasticity in Göttingen, Germany. merical calculations have two goals: (1) igation of the buffet boundary on the fixed airfoil under transonic flow conditions, r investigations on the airfoil under aero elastic conditions. the flutter calculations it has been shown that in addition to the Mach number, the neutral position of the torsion spring is of considerable importance for the investigation. Therefore this parameter has been studied in some detail. cal results obtained are presented in suitable form and compared with available experimental data.