Experimental investigation of angle of attack effects on aerodynamics characteristics of delta wing-body-vertical tail combination airplane model in ground effects

Aerodynamic characteristics of an aircraft with delta wing are considerably affected under the ground effect in take-off and landing phases. In this research, static ground effect of a 60 degrees delta wing with axisymmetric sharp edges in combination of body and vertical tail at low speed wind tunnel are investigated. The wind tunnel is closed type has an opened test section that its dimensions is 2.8 m × 2.2 m and maximum velocity is 90 m/s. In these tests ground effect is simulated using a fixed plane that its height is variable. With decreasing the height from the ground plane, the lift force is increased, induced drag force is decreased, total drag force is increased and nose-down pitching moment is increased nonlinearly. The rate of increasing of lift coefficient in linear regions increased with decreasing of height from ground plane. At the positive angle of attack the most percentage increasing of lift coefficient is due to 5 degrees angle of attack as the result of existence of perfect vortex flow over the whole wing surface. The minimum case is due to 30 degrees of angle of attack.