Influence of "AT winglets" wingtip type on the aerodynamic characteristics of wings

Abstract

In this article by the method of equations of steady horizontal flight the impact «AT winglets» wingtips on the wing aerodynamic quality is explored. The total aerodynamic force, created by all four parts of the wingtips is determined. The vector of the total aerodynamic force of the wingtips is represented in the form of components of a linked coordinate system. Equilibrium equations for the steady motion of an aircraft with «AT winglets type wing tips in a horizontal flight are recorded. From these equations it is obtained that, in the direction of motion, the longitudinal component of the vector of the total aerodynamic force of the tips reduces the inductive drag of the wing (increases the thrust of the engines), the vertical component is added to the lifting force of the wing and increases it, and the lateral components, due to the symmetry of the wing, are in balancing state. It is shown that the lifting force created by the «AT winglets» type wingtips is larger compared to the same ones created by the upper wingtips. An important consequence is that the distribution of the lifting force over the wing span with double tips is more uniform in comparison with the wing without a wingtip or with a wing with the upper wingtip. The expression for the effective aspect ratio of the wing with the tips is defined, which is greater than the inductive drag of the wing without the tip. An important consequence is obtained: at the constant weight of the aircraft, the product of effective wing aspect ratio with the «AT winglets» wingtips and only the upper wingtips by their coefficients of inductive resistance is equal to the product of the wing aspect ratio without a tip by its coefficient of inductive drag.