NUMERICAL INVESTIGATION OF FLOW ON A DARRIEUS VERTICAL AXIS WIND TURBINE BLADE WITH VORTEX GENERATORS

摘要

This paper intends to improve the Darrieus wind turbine performance by using a new design of vortex generators. Computational fluid dynamics (ANSYS CFX.15) have been used to simulate the turbine in steady state and incompressible flow with Reynolds number Re=2.05×10~5. The shear stress transport k-ω turbulence model has been used to complete the governing equations, and the vertical axis wind turbine (VAWT) has been modeled in three dimensions. The geometric parameters' (the vortex generators and their sizes with respect to the profile) influence on the performance of VAWTs is studied. The first part of this work presents the flow behavior around the smooth airfoil, for a different angle of attack, which is compared with experimental data. The second part studies the passive control effect of the vortex generators (VGs) placed first on the extrados, then on the intrados, and finally on the two sides, for different VG heights. This research indicates the VAWT's performance can be greatly improved by correctly choosing the size and position of the VG, in which the smaller height of VG increases the tangential coefficient considerably.