Abstract: bstract： Combining with rigid dynamic mesh technique, a new systematic method to calculate combined and single dynamic derivatives was developed taking longitudinal direction as an example. First, the combined derivative was extracted using the differential method by forcing the aircraft pitching to the same angle of attack (AOA) with two identical pitching rates. Then, acceleration derivative were obtained by forcing the aircraft plunging to the same AOA with two constant accelerations. Finally, the angular velocity derivative was identified by the combination of constant pitching and plunging motion. To discuss the evaluation of dynamic derivatives computed using the three CFD methods, two configurations, that is, the stability and control configuration (SACCON) and Finner missile model, were considered. The results presented are in good agreement with the available experimental data which shows that each single derivative has a different proportion of the combined derivative of different geometries. Compared to general CFD methods, the unsteady motions used in the new methods are much simpler and more effective, and the methods can also be used for combined and single lateral and directional dynamic derivatives identification.

Key words: Key words： computational fluid dynamics (CFD), combined dynamic derivative, acceleration derivative, angular velocity derivative, numerical simulation