The Vertical Axis Wind Turbine Efficiency Evaluation by Using the CFD Methods

In this paper, numerical studies have been conducted in order to evaluate the efficiency of a vertical axis wind turbine by using CFD methods. For these studies, it has been used SIMPLE type pressure-based coupled solver. The complexity and the unsteadiness character of the flow in such a machine, requires the use of unsteady RANS models. To determine the accuracy of the solution obtained by URANS models, this paper makes a comparative analysis with the same case and LES modeling. Analyses were performed with a 2D grid consisting of two regions, a rotor and a stator. The airfoil of the VAWT is a classic NACA0018. Results indicate that the poor accuracy of the URANS CFD method is mainly due to its limitation in the vortex modeling. In general the LES modeling have a better agreement with the experimental results from the wind tunnel.

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