Aeroservoelastisches Modell zur Beschreibung der instationären Aerodynamik für nichtlineare beliebige Eingangsgrößen im Zeitbereich
type: CreativeWork
description: In this thesis an aeroservoelastic model for an airfoil-rudder-system with three degrees of freedom is established in time domain. This leads to the design of control laws for active flutter suppression. The response of the unsteady aerodynamics and the system behav-iour with respect to a non-linear time dependent doublet deflection of the rudder and the angle of attack are calculated. An integrated areoservoelastic model in time domain is set up by means of the indicial concept. The unsteady aerodynamics in incompressible and compressible flow for arbi-trary movements is approximated by indicial functions using the following approach: 1. The aerodynamic forces and moments are derived in integral form from the lin-earized potential theory.2. The indicial functions are validated for compressible and incompressible flow in frequency and time domain.3. The lift system for arbitrary variations of angle of attack, pitching and rate of rud-der deflection is derived from DUHAMEL-superposition integral.4. The transfer function of the lift system is derived by LAPLACE transformation.5. The state space equation for the airfoil-rudder-system for unsteady aerodynamics in compressible and incompressible flow are set up.6. The differential equations of motion of the airfoil-rudder-system are expressed by the LAGRANGE equations of second kind and combined with the aerodynamic equations to the aeroelastic system.7. The validation of the aeroelastic is carried out by comparison of the flutter speed using the root locus method according U-g-method, p-k-method and g-method from literature. The three most important results of this work are three new formulas for the approxima-tion of the unsteady aerodynamics for incompressible and compressible flow: 1. A new and better constant for the approximation of the WAGNER function in in-compressible flow. The indicial function is validated by comparison with the THEODORSEN function in LAPLACE domain. Compared to other approximations this proce…
abstract: In this thesis an aeroservoelastic model for an airfoil-rudder-system with three degrees of freedom is established in time domain. This leads to the design of control laws for active flutter suppression. The response of the unsteady aerodynamics and the system behav-iour with respect to a non-linear time dependent doublet deflection of the rudder and the angle of attack are calculated. An integrated areoservoelastic model in time domain is set up by means of the indicial concept. The unsteady aerodynamics in incompressible and compressible flow for arbi-trary movements is approximated by indicial functions using the following approach: 1. The aerodynamic forces and moments are derived in integral form from the lin-earized potential theory.2. The indicial functions are validated for compressible and incompressible flow in frequency and time domain.3. The lift system for arbitrary variations of angle of attack, pitching and rate of rud-der deflection is derived from DUHAMEL-superposition integral.4. The transfer function of the lift system is derived by LAPLACE transformation.5. The state space equation for the airfoil-rudder-system for unsteady aerodynamics in compressible and incompressible flow are set up.6. The differential equations of motion of the airfoil-rudder-system are expressed by the LAGRANGE equations of second kind and combined with the aerodynamic equations to the aeroelastic system.7. The validation of the aeroelastic is carried out by comparison of the flutter speed using the root locus method according U-g-method, p-k-method and g-method from literature. The three most important results of this work are three new formulas for the approxima-tion of the unsteady aerodynamics for incompressible and compressible flow: 1. A new and better constant for the approximation of the WAGNER function in in-compressible flow. The indicial function is validated by comparison with the THEODORSEN function in LAPLACE domain. Compared to other approximations this proce…
author: Wang, Wen
language: ger
keywords: info:eu-repo/classification/ddc/620, Ingenieurwissenschaften, aeroservoelastisches Modell, Approximation der instationären Aerodynamik, Zustandsgleichung, beliebige Eingangsgröße, im Zeitbereich, Aeroservoelastic model, approximation of the unsteady aerodynamics, state space equation, arbitrary input, time domain
date published: 2006
date modified: 2026-07-30T19:43:10Z
provider: RWTH Aachen University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Publikationsserver der RWTH Aachen University