Passive flow control in wind turbine blade by geometrical optimization of vortex generator

Abstract

A wind turbine is a device that converts mechanical energy into electrical energy by its rotary action. In this paper, a wind turbine’s lift and power characteristics are improved by employing a vortex generator as a passive flow control device on the surface of the wind turbine. A triangular vortex generator is used for this study for its simplicity in design and effective results. NACA 4418 airfoil is selected for the conceptual design by BEM (Blade Element Momentum theory), and geometrical modeling is carried out using SOLIDWORKS. Computational analysis of the blade with vortex generators is done using ANSYS CFX, and analysis on a clean blade is verified using Q Blade. The geometrical parameters considered for optimization are chordwise position (xvg), Height (hvg), and Inclination from the baseline(βvg), keeping fixed spacing (svg). By optimizing the design parameters, the lift and power increment is observed alongside a delay in the flow separation point, which agrees with the experimental results. This investigation can be extended to future unconventional shapes such as ogive, vane, and wishbone generators through wind tunnel and field tests.