Predicting stability derivatives of flying wing aircraft based on improved vortex lattice method

Because the absence of vertical stabilizer causes neutral or slightly negative yaw stiffness, the flying wing aircraft differs from conventional configuration aircraft in lateral directional stability. Thus in the conceptual design stage of tailless aircraft, not only aerodynamic characteristics need to be optimized, but also the relatively accurate stability derivatives are necessary to analyze the dynamic stability of aircraft. It requires higher accuracy and efficiency of aerodynamic calculation program. An improved vortex lattice algorithm is proposed in this paper. A certain tailless aircraft is chosen to be tested in wind tunnel and calculated with the improved algorithm. The comparison of the results shows that the improved algorithm has made progress in accuracy during sideslip.