Vertical-axis wind turbine flow characteristics and momentum transfer using the eddy covariance method

Abstract

Micro-turbulence statistics of pre- and post- vertical axis wind turbine (VAWT) flows could increase our understanding of VAWT turbulence generation and its quantification and the effect of turbulence on wind turbine efficiency. Thus, the aim of this research was to explore the micro-turbulence parameters of pre- and post- wind turbine flows. High-frequency three dimensional, longitudinal, lateral, and vertical, wind velocities fluctuations of a VAWT at specific positions were measured by a sonic anemometer at two different flow speeds. The turbulence statistics profile were calculated using the eddy correlation (EC) method. Both speed 1 (low) and speed 3 (high) settings, exhibited similar trends but at different magnitudes. At downwind position, the wind speed was lower while the vertical turbulence component decreased in a small amount at the centre vertical line, with the turbine within the flow. Besides increasing the understanding of micro-turbulence flow of wind turbine, this exploratory study can serve as a starting point and baseline data to develop the methodology for quantifying turbulence statistics for wind turbine in the future.