On effectiveness of turn winglets using in the capacity of wing mechanization elements

Аuthors

Tyutyunnikov N. P.^*, Shklyarchuk F. N.^**

Institute of Applied Mechanics of Russian Academy of Science, IAM RAS, 32a, Leninskii av., Moscow, В-334, GSP-1, 119991, Russia

*e-mail: nicpet@list.ru
**e-mail: shklyarchuk@list.ru

Abstract

Aerodynamic characteristics of large elongation straight elastic wing with turn winglets are analyzed. The discrete vortex method is used for determination of the aerodynamic load distribution. Mathematical model of the wing structure is developed using the bay method as a finite element method with enlarged elements of a thin-walled beam subjected to bending, transverse shear and torsion. These methods are used to solve coupled aeroelasticity problem. Aerodynamic load distribution for elastic wing and its divergence velocity are determined. Dependence of the aerodynamic characteristics from the winglet turning about longitudinal axis for some of its locations are analyzed.

Aerodynamic symmetric and antisymmetric load distribution taking into account the turning of the winglets is considered in this paper. The winglets can duplicate and even execute the functions of the wing regular mechanization elements as ailerons. The use of winglets can be particularly efficient for small aircraft with large elongation elastic wings.

For determining the aerodynamic load the wing is divided on small finite panels with one joined vortex and two end free vortexes of constant unknown circulations. Flow non-separation conditions are satisfied in one point of the panel.

Using bay-method the wing is divided to bays by cross sections. The bay stiffness matrixes are determined using the theory of thin-walled beams. Displacements, angles of rotations, and twisting in the joints of the bays are considered as generalized coordinates. The total stiffness matrix is constructed by standard procedure of finite element assembling.

As an example aerodynamic load distribution and divergence velocity are calculated for straight wing with turn winglets.

The proposed technique makes it possible to estimate the efficiency of the turn winglet control by aerodynamic and aeroelastic characteristics of wings. Calculations executed for typical structure of straight wing with large elongation show that using of that winglets may be efficient tool for wing aerodynamic characteristics control. The winglets can act as ailerons to control the antisymmetric motion of aircraft.

Using of the turn winglets evidently is most reasonable for light aircraft with rather compliant wings of large elongation.

Keywords:

aerodynamic characteristics, control, big elongation wing, turn winglets, discrete vortex method, bay method, aeroelasticity

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