Recent NASA Research on Aerodynamic Modeling of Post-Stall and Spin Dynamics of Large Transport Airplanes

A simulation study was conducted to investigate aerodynamic modeling methods for prediction of post-stall flight dynamics of large transport airplanes. The research approach involved integrating dynamic wind tunnel data from rotary balance and forced oscillation testing with static wind tunnel data to predict aerodynamic forces and moments during highly dynamic departure and spin motions. Several state-of-the-art aerodynamic modeling methods were evaluated and predicted flight dynamics using these various approaches were compared. Results showed the different modeling methods had varying effects on the predicted flight dynamics and the differences were most significant during uncoordinated maneuvers. Preliminary wind tunnel validation data indicated the potential of the various methods for predicting steady spin motions. Nomenclature α = angle of attack, degrees ave α = average value of α β = angle of sideslip, degrees ave β = average value of β b p = body-axis roll rate, degrees/second or radians/second b q = body-axis pitch rate, degrees/second or radians/second b r = body-axis yaw rate, degrees/second or radians/second Ω = total angular rate, degrees/second xz Ω = projection of the total angular rate into the body-axis x-z plane, degrees/second ω = wind-axis (velocity-vector) roll rate, degrees/second or radians/second ave