Deformation and aerodynamic characteristics of a membrane wing airfoil in subsonic flow

Аuthors

Grishanina T. V.^1*, Shklyarchuk F. N.^2**

1. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
2. Institute of Applied Mechanics of Russian Academy of Science, IAM RAS, 32a, Leninskii av., Moscow, В-334, GSP-1, 119991, Russia

*e-mail: t.grishanina@mai.ru
**e-mail: shklyarchuk@list.ru

Abstract

In this work a membrane wing of large aspect ratio in subsonic flow is considered. The wing consists of the front thin-walled beam and the rear beam connected in some transverse sections by ribs and by presstressed plane membranes located between the ribs. To calculate the deformed shape and aerodynamic characteristics of the wing we consider the plane problem for the wing airfoil.

The aerodynamic pressure acting on the deformed airfoil in subsonic flow is determined by using the exact solution in the series. The finite element method (FEM) is used to determine the small membrane deflections. The coupled problem of airfoil aeroelasticity is described by the system of linear algebraic equations for the node displacement of the FE-model. Solving this system we find the distribution of the aerodynamic pressure and the aerodynamic coefficients for the airfoil lift and moment. Besides these we find the boundary of the membrane divergence when the membrane turns up.

The example of the membrane airfoil is considered for which the numerical results are obtained in terms of the nondimentional parameter representing the ratio of the kinetic energy head to the membrane tension. Regulating the membrane tension by changing the rib lengths makes possible to control the aerodynamic characteristics of the airfoil and the wing on the whole without moveable aerodynamic control surfaces.

The results of this research can be used in design of the superlight high altitude unmanned aeroplanes with large duration of the flight.

The proposed method of the solution to a new aeroelasticity problem is original and the obtained results coincide with the exact solution in the particular case of the rigid airfoil.

Keywords:

airfoil of a membrane wing, subsonic flow, aeroelasticity, aerodynamic characteristics, divergence

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