Aircraft Directional Stability Prediction method by CFD

The aim of this paper is to present a new method to predict aircraft directional characteristics. The proposed approach is completely CFD based and it has been developed with more than 300 simulations of complete and partial aircraft configurations. The method accounts for mutual aerodynamic interference effects among components. First, the isolated vertical tailplane and fuselage yawing moment coefficients are calculated. Then, correction factors are applied to take into account for aircraft components (fuselage, wing, vertical and horizontal tailplanes). The corrected yawing moment coefficients represent the contributions of vertical tailplane and fuselage to aircraft directional stability, including the aerodynamic interference among all aircraft components. Finally, the method is tested and compared to typical semi-empirical approaches (USAF DATCOM, ESDU)