Large eddy simulation of cross flow past bluff bodies using a stabilised finite element method

• Autor(a) principal: Sampaio, Paulo Augusto Berquó de Sampaio
• Data de Publicação: 2001
• Outros Autores: Instituto de Engenharia Nuclear, Diretoria do IEN, [e-mail], http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4781815A6
• Tipo de documento: Relatório
• Idioma: por
• Título da fonte: Repositório Institucional do IEN
• Texto Completo: http://carpedien.ien.gov.br:8080/handle/ien/1638
• topic: Large eddy simulation; Petrov-Galerkin method; Turbulent flow

Nowadays, aerodynamic of the behavior of some slender structures in performed by means of computational flui dynamics (CFD), as a complementary tool for wind tunnel-tests. In this paper a Large Eddy Simulations (LES) procedure is proposed for the study of two-dimensional incompressible cross flow around stationary bluff bodies at high Reynolds number. Instead of adopting an explicit sub-grid stress model, the effect of the unresolvable scales is accounted for implicity through the use of a stabilized Petrov-Galerkin formulation. The stabilizing terms act as filters that damp the growth of numerical errors associated to sub-grid phenomena, i.e. flow features smaller/faster than the local space/time resolution. The first numerical example refers to a square cylinder under smooth oncoming flow. Results are compared with some experimental wind-tunnel tests and with other numerical results. The flow around a dominant central span section of the Rio-Niterói Bridge is taken as a second example. This continuous steel twin box girders bridge exhibits vortex-induced oscillation in the first bending mode when subjected to cross winds of relatively low velocities. In order to explore results from distinct flow past the bluff body, the bridge section is modeled using different appendages and edge barriers with different geometries. Results for the models are analysed in the light of experimental results obtained in wind-tunnel tests for a sectional model of this bridge. The effects of changes in bridge section profile due to the presence of large vehicles is considered in another simulation by comparing results with those obtained from the isolated section model.