Influence of Aerodynamic Characteristics of Airfoil Forward Flight Considering Step-Type Ground

Abstract

The aerodynamic influence of ground effects during forward flight is difficult to ignore, especially when there is a sudden change in the ground structure. The aerodynamic performance of the airfoil during forward flight is investigated using the NACA4412 airfoil, the correlation between two factors, i.e., height and angle of attack, and the aerodynamic performance of the airfoil are analyzed. The results show that under the effect of step-type ground, the wing forward flight causes a steep drop in lift-to-drag ratio when the ground effect is absent, and there is a linear relationship with the height above the ground. The angle of attack from the ground has an inverse relationship with the sudden change in aerodynamic performance, i.e., the airfoil needs to maintain a large angle of attack when it leaves the ground in order to reduce the steep change in aerodynamic performance. The take-off and landing process of a shipboard aircraft is typical of a step-type ground. This paper provides a reference for the aerodynamic design of an airfoil under the influence of ground effects.

Keywords

• step-type ground
• ground effect
• pneumatic characteristics
• forward flight