ISBN 9783843921329

978-3-8439-2132-9, Reihe Luftfahrt

Bae Hong Chen
Numerical Analysis of the Influence of a Winglet Actuated Control Surface by Means of Direct and Reduced-Order-Model Simulation

137 Seiten, Dissertation Rheinisch-Westfälische Technische Hochschule Aachen (2014), Softcover, A5

Zusammenfassung / Abstract

The usage of Computational Aero-Structural Dynamics (CASD) and different kinds of Reduced Order Models (ROM) methods for the preliminary design of new airplane concepts and the validation of such tools have been the matter of many research programs in recent years. This includes especially the prediction of dynamic aeroelastic phenomena, which are caused by the interaction of the wing's elastic and inertial properties with the ambient flow. The prediction of these phenomena is still very challenging. In this context, the transfer project Aero-Structural Dynamics Methods for Airplane Design (ASDMAD) was initiated. Herein, a new winglet concept with an additional movable control surface (WACS) was constructed, built and tested. The purpose of this work is the assessment of the functionality and efficiency of the WACS by means of the numerical method SOFIA. Furthermore, a ROM method is developed to predict the unsteady wing deformation due to forced vibrations by means of the root excitation mechanism and the harmonically moved WACS for the use in a feedback control system. The investigated wing geometry is based on the redesigned supercritical wing model from the HIRENASD project. The modifications were mainly focused on the wing-tip region, which was shortened for the attachment of different winglets. According to the applicability of the WACS, the investigation is divided into two parts, in which the control surface in the computations is assumed to be free from rotational inertia and massless. First, the static usage is studied with the WACS at fixed deflection angles. The main purpose of a static usage

is to reduce structural deformations and loads caused by the winglet, and thus, to expand the cruise condition range in which the winglet is effective. In the second part of the investigation, the influence of a dynamically operated ACS is studied for three different applications. This includes the observation of the ACS effect on an aeroelastic equilibrium state during decay process and forced vibration. In the last part of this work, the applicability of the ROM method is demonstrated by means of two wing configurations, one being the ASDMAD-2 configuration including the WACS. It is shown that the method is highly accurate for the rapid computation of unsteady aerodynamic and aeroelastic responses. This is also the case if only the first-order linear kernel is used in favor of reducing the computational effort for the kernel identification.