عنوان مقاله [English]
An intensive experimental investigation was conducted to study the effect of vertical tail, single and twin (with different cant angles) on the flow field and the corresponding aerodynamic forces and moments of a model of a fighter A/C. Aerodynamic forces under different flight conditions and different vertical tail settings were measured in a supersonic wind tunnel. Furthermore, effects of vertical tail on the model wake at subsonic speed were investigated. In addition to the force and pressure measurements, schlieren system was used to visualize the shock formation and movement oat various locations on the model. The results show existence of a pair of symmetric vortices for the model equipped with a 22 degree vertical tail cant angle. The vortices burst symmetrically at moderate angle of attack. The drag coefficient increases with increasing cant angle at low to moderate alpha and decreases when alpha is further increased.