| Título: | Stability investigation of a nonlinear variable airfoil camber |
| Autor: | Henrique Osório Menchon Felcar |
| Programa: | Ciências e Tecnologias Espaciais |
| Área de Concentração: | Sistemas Espaciais, Ensaios e Lançamentos |
| Orientador : | Roberto Gil Annes da Silva |
| Ano de Publicação : | 2017 |
| Curso : | Mestrado Acadêmico |
| Assuntos : | Aeroelasticidade |
| t | Não-linearidade |
| t | Estabilidade |
| t | Vibração aeroelástica |
| t | Escoamento incompressível |
| t | Engenharia aeronáutica |
| Resumo : | A variable airfoil camber proposes to reduce loads of lifting surfaces. The system stability is investigated in an incompressible flow using a two-dimensional four degree of freedom model on pitch, plunge, slat and flap angles, in which the kinematic of slat and flap are coupled by a linear relationship. Concentrated cubic structural restoring forces as effect of nonlinearities are considered. The aeroelastic governing equations are written and integrated numerically using a fourth order Runge-Kutta scheme for the time domain evaluations. The identification and stability analysis of limit cycle oscillations are presented for a range of the system parameters. Evaluations of the Duhamel and the quasi-steady approximations; and a method in the frequency domain using describing functions combined with the Sherman-Morrison formula are compared. Double period, quasi-periodic and chaos phenomenon were identified, being strictly dependent to initial boundary conditions. |
| Data de Defesa : | 03/08/2017 |
| Texto na íntegra : | [Visualizar] |