Banca de DEFESA: CARLOS VITOR DA SILVA SARMENTO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CARLOS VITOR DA SILVA SARMENTO
DATE: 25/04/2023
TIME: 14:30
LOCAL: Pós-Graduação Engenharia Civil
TITLE:

Formulation for the Structural Gallop in Three Degrees of Freedom Via the Finite Element Method: Application in Dynamics Analysis of Wind Turbines with a Non-circular Section Tower

KEY WORDS:

structural gallop; finite element; dynamic analysis; wind turbine; non-circular section.

PAGES: 225
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

The wind energy potential provides an alternative for obtaining electricity in a clean way and with low environmental impact. With this, the global wind sector has been undergoing a constant evolution in its scenario regarding the implementation of parks and development of new technologies. With the increase in the dimensions of wind turbines (upscaling), new towers have been implemented with the aim of overcoming transportation and installation limitations. Among these structures, the following stand out: Hexcrete, tetradecagonal and modular. By escaping from the towers with conventional circular sections, new effects must be considered in the dynamic analysis, among them the structural gallop, which is a phenomenon of aerodynamic instability responsible for causing an increase in the amplitude of the tower (Displacements and rotations). Unlike the circular sections, the analyzed towers have variations in aerodynamic coefficients as a function of the angle of attack. This approach allows analyzing regions susceptible to structural gallop considering the three degrees of freedom: two translational (parallel and transversal to the wind direction) and one rotational. To obtain the aerodynamic coefficients, and their derivatives, computer simulations were performed for the sections in question through the ANSYS program in its CFX module. Once the numerical tests were carried out, abacuses were created for application in the structural module. To compute the aerodynamic loads of the rotor, simulations were performed in the FAST program, using the NREL 5-MW model turbine, allowing validations with the literature. In possession of the aerodynamic parameters of the tower and load on the rotor, it was applied in the code in MATLAB. Comparisons with the other formulations found in the literature for structural and aerodynamic damping indicated that the three-degree-of-freedom (MEF) system provides the designer with the ability to indicate regions more vulnerable to structural gallop, and also allows capturing effects not computed by the other analyses. that may impact structural stability. The tower was analyzed for different sections (non-circular) and adopting various load cases and wind incidence angle, evaluating the susceptibility to aerodynamic instability.

COMMITTEE MEMBERS:
Externo à Instituição - JOSÉ LUÍS VITAL DE BRITO - UnB
Externo ao Programa - 2858245 - DOUGLAS MATEUS DE LIMA - nullExterno à Instituição - GUSTAVO DE NOVAES PIRES LEITE - IFPE
Externo ao Programa - 1329483 - PAULO FERNANDO SILVA SOUSA - nullPresidente - 2994651 - TIAGO ANCELMO DE CARVALHO PIRES DE OLIVEIRA