Estudo numérico tridimensional da vibração induzida por vórtices sobre um cilindro rígido elasticamente apoiado com um e dois graus de liberdade

• Ano de defesa: 2019
• Autor(a) principal: Brito, Vinícius Ribeiro dos Santos de Sá
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Rio de Janeiro; Brasil; Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia; Programa de Pós-Graduação em Engenharia Oceânica; UFRJ
• Palavras-chave em Português: Navier-Stokes; Simulação direta das grandes escalas de turbulência; Dinâmica dos fluidos computacional; Vibração induzida por vórtices; CNPQ::ENGENHARIAS::ENGENHARIA NAVAL E OCEANICA
• Link de acesso: http://hdl.handle.net/11422/13657

This work addresses the response of a cylindrical structure to three-dimensional incident flow. Initially, the numerical code is validated using the fixed cylinder. Then, an investigation of the vortex-induced vibration response (VIV) is performed, in one and two degrees of freedom. In order, the cylinder will be supported by a spring and a damper and will be free to vibrate in the transverse direction and then also in the longitudinal direction to the flow. To solve the slightly compressible Navier-Stokes equations together with the dimensionless equation of cylinder motion, the Finite Differences Method and the third-order Runge-Kutta method are used for integration in time. The boundary conditions on the body are imposed using the Immersed Boundaries Method. The turbulent flows are solved using the Large Eddy Simulation (LES). The Smagorinsky model is used to simulate the dissipative effects of small scales. Results for temporal series of the drag coefficient, lift coefficients, vorticity contour, displacement amplitude, frequency and phase angle are analyzed. The present work is a pioneer in the three-dimensional numerical study of VIV in 2 degrees of freedom that analyzes in detail the wake and the vortex shedding modes.