| Summary: | 碩士 === 國立臺灣海洋大學 === 系統工程暨造船學系 === 94 === Abstract
The Horizontal Axis Wind Turbine (HAWT) is the most widely used wind power machine, and the objective of this thesis is to compute the flow field around an HAWT. The computational methods used in this thesis are the blade element momentum (BEM) theory and the viscous flow RANS method, and the computational results are validated by experimental data. In this thesis, different computational methods applied to the wind power turbines are first introduced, and the blade element momentum theory with the tip loss corrections and RANS are especially emphasized.
The computational example presented in this thesis is a wind turbine which has been experimented in the NASA Ames Lab., and the foil geometry used by this turbine is a foil especially designed for the wind turbine named S809. The computational results of this two-dimensional foil by RANS are first presented, and the computational results agree well with the experimental data. A multi-layer grid system is found to be the most proper grid arrangement for 3-D wind turbine computations. The computational results of the three-dimensional wind turbine by RANS, including torque, local forces and pressure distributions, are then shown and discussed. The BEM theory with a tip loss correction gives a very good prediction for the torque; however, without the ability to show the detailed forces and flows. The comparisons between the computational results of the RANS method and the experimental data are encouraging. Although the predictions of torques are not as well as the BEM theory, RANS results provide information of the local forces and detailed flows.
Keyword：wind turbine, RANS, blade element momentum theory, airfoil
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