Investigation of the tail dihedral effects on the aerodynamic characteristics for the low speed aircraft

The aerodynamic characteristics for the vee-tail aircraft configuration have been investigated numerically at low Reynolds number (Re<106). Three types of vee-tails have been adopted to be compared with the conventional tail type (with horizontal and vertical tails). The results show that the effect created by the vee-tail can greatly affect the aerodynamic characteristics of the whole aircraft. If the dihedral angle of the vee-tail is too large, it can directly affect the flight stability. The main reason for the longitudinal moment curve "moving up" at high dihedral angle can be attributed to the serious asymmetric downwash effect. Based on these, the force variation and the corresponding aerodynamic characteristics for three different sizes of aileron with different deflection angles have also been obtained computationally and analyzed in detail.