Abstract:
A waverider aircraft faces the problem regarding lateral-directional coupled dynamic stability due to its non-axisymmetric, flat and slender geometry. The study of the lateral-directional stability of a waverider is relatively limited in the current literature, and instructive conclusions can hardly be found. To investigate the lateral-directional stability, a power-law waverider was taken as the objective, whose Dutch roll mode characteristic was studied in detail. First, the design parameters
kw and
φ were introduced to describe the geometry of the waverider. The static and dynamic derivatives of the waverider for the whole design parameter space were computed by using CFD and Kriging surrogate model. Then, the characteristics of the Dutch roll mode were obtained according to the solution of linearized small-disturbance equations for lateral-directional motions. An approximate expression was derived for the damping of the Dutch roll mode. A new concept of dynamic stability derivative of the Dutch roll mode was defined. The reason for the divergence or convergence of the Dutch roll mode was analyzed with the help of the approximate expression. The distribution of the damping was obtained at different angles of attack. For the frequency of the Dutch roll mode, an approximate expression was derived, and the variation of the frequency was also analyzed followed by the changing design parameters and angles of attack.