On the Response of Horizontal and Vertical Axis Wind Turbines to Turbulence: A Wind Tunnel Experiment

The turbulent flow modulation on the unsteady behavior of a model VAWT is investigated and compared with a model HAWT of similar size in a laboratory experiment. The turbines operated in low and high freestream turbulence. The research was performed at the Talbot Laboratory wind tunnel at the University of Illinois at Urbana-Champaign (UIUC). High-resolution measurements of the turbine voltage for a small, 12 cm HAWT and a 16 cm VAWT are acquired at high temporal resolution, sufficient to capture the turbulent scales of flow relevant to the problem. Both turbines were built at the UIUC rapid prototyping lab and have realistic airfoil shapes. An understanding of the distinctive physical processes modulating the scale-to-scale fluctuating behavior in a VAWT and a HAWT exposed to the same turbulent flow conditions is discussed. A relation between turbulent motions and fluctuating behavior is extended from the knowledge of HAWTs to VAWTs.Copyright © 2014 by ASME