• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.220-225
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• 2013

In this study, active control system using sliding mode control method is presented to achieve the gust response alleviation of a three-dimensional flexible wing model. For this purpose, aeroservoelastic model which is composed of aeroelastic plant, control surface actuator model, and gust model depicting the atmospheric turbulence is formulated in the state space. The aerodynamic force generated by the motion of a trailing edge control surface of a flexible wing is made use of as control means. An active control system combining state feedback sliding mode controller and state estimator based on measured responses such as wing tip acceleration and wing root strain is designed for gust response alleviation of a flexible wing aeroservoelastic model. The performance of the controller designed is demonstrated via numerical simulation for the representative flexible wing model under gust loading conditions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.185-195
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• 2021

The flapping-wing micro air vehicle (FW-MAV) in this study utilizes the cambered wings made of quite flexible material. Similar to the flying creatures, the present cambered wing uses three different materials at its leading edge, vein, and membrane. And it is constrained in various conditions. Since passive rotation uses the flexible nature of the wing, it is important to select an appropriate material for a wing. A three-dimensional fluid-structure interaction solver is developed for a realistic modeling of the cambered wing. Then a parametric study is conducted to evaluate the aerodynamic performance in terms of the elastic modulus of leading edge and vein. Consequently, the elastic modulus plays a key role in enhancing the aerodynamic performance of FW-MAVs.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.4
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• pp.310-323
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• 2013

In this paper, the aeroelastic static response of flexible wings with arbitrary cross-section geometry via a coupled CUF-XFLR5 approach is presented. Refined structural one-dimensional (1D) models, with a variable order of expansion for the displacement field, are developed on the basis of the Carrera Unified Formulation (CUF), taking into account cross-sectional deformability. A three-dimensional (3D) Panel Method is employed for the aerodynamic analysis, providing more accuracy with respect to the Vortex Lattice Method (VLM). A straight wing with an airfoil cross-section is modeled as a clamped beam, by means of the finite element method (FEM). Numerical results present the variation of wing aerodynamic parameters, and the equilibrium aeroelastic response is evaluated in terms of displacements and in-plane cross-section deformation. Aeroelastic coupled analyses are based on an iterative procedure, as well as a linear coupling approach for different free stream velocities. A convergent trend of displacements and aerodynamic coefficients is achieved as the structural model accuracy increases. Comparisons with 3D finite element solutions prove that an accurate description of the in-plane cross-section deformation is provided by the proposed 1D CUF model, through a significant reduction in computational cost.