Otimização e dinâmica dos fluidos computacional aplicadas a turbinas eólicas

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2012

RESUMO

The present work consists in the application of optimization methods and computational fluid dynamics to wind turbines. The massive growth in renewable energies demands more powerful turbines and more accuracy in their design and analysis. This work has three objectives: optimization of an airfoil for wind turbines, simulation of a wind turbine airfoil in deep stall, and simulation of a three-dimensional wind turbine. The airfoil optimization is accomplished by means of two-dimensional steady-state Reynolds averaged Navier-Stokes simulations with the Spalart-Allmaras turbulence model, with genetic algorithms coupled with artificial neural networks. The airfoil in deep stall is calculated with unsteady three-dimensional Large Eddy Simulations with the dynamic Smagorinsky model. The simulation of a wind turbine is also done by means of the Reynolds averaged Navier-Stokes equations, with an additional term to take the Coriolis forces into account, and the Spalart-Allmaras turbulence model. In the first application, it can be confirmed that the two-dimensional steady state simulations are very accurate for the reference airfoil, with good agreement for drag, lift, and pressure coefficients. Genetic algorithms improved the lift-to-drag ratio about 8%, with a 50% decrease in computational time when using artificial neural networks. For the second application, the airfoil with a high angle of attack showed that transient three-dimensional simulations were indeed required, with a high variation of aerodynamic coefficient as a function of time and the highly three-dimensional wake. In the final part, the three-dimensional wind turbine showed very good agreement with experimental results. A great deal of attention was devoted to the creation of the grid and a mesh with only 700 thousand elements was achieved, while other authors used from 3 to 38 million elements for the same case.

ASSUNTO(S)

dinâmica dos fluidos computacional aerodynamics numerical simulation simulação numérica airfoil turbinas eólicas

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