8 research outputs found
Computational fluid dynamic analysis of roof-mounted vertical-axis wind turbine with diffuser shroud, flange, and vanes
Advances in wind power and tidal power have matured considerably to
offer clean and sustainable energy alternatives. Nevertheless,
distributed small-scale energy production from wind in urban areas has
been disappointing because of very low efficiencies of the turbines. A
novel wind turbine design-a seven-bladed Savonius vertical-axis wind
turbine (VAWT) that is horizontally oriented inside a diffuser shroud
and mounted on top of a building-has been shown to overcome the drawback
of low efficiency. The objective this study was to analyze the
performance of this novel wind turbine design for different wind
directions and for different guide vanes placed at the entrance of the
diffuser shroud. The flow field over the turbine and guide vanes was
analyzed using computational fluid dynamics (CFD) on a 3D grid for
multiple tip-speed ratios (TSRs). Four wind directions and three
guide-vane angles were analyzed. The wind-direction analysis indicates
that the power coefficient decreases to about half when the wind is
oriented at 45 degrees to the main axis of the turbine. The analysis of
the guide vanes indicates a maximum power coefficient of 0.33 at a vane
angle of 55 degrees