Researchers modeling how changes in air flow patterns affect wind turbine output power have found that the wind can supply energy from an unexpected direction: below. The researchers introduced a mathematical way to measure changes in the flow that gives a more accurate representation of the magnitude of these changes than other current measures. It shows that in addition to energy being made available to the turbines from above, energy is also transferred from below.
The tools and methodologies developed by the team for calculating changes in the flow can now be applied to other studies, for any type of flow with a repetitive pattern. Since they were also able to show that energy comes from below the rotors, it may be possible to exploit this by developing wind farms that draw more heavily on this previously unidentified source of energy.
Going forward, the researchers plan to further expand the scope of their model by applying the analysis to the case of two-bladed vs. three-bladed turbines to identify the critical differences in flow patterns and how these affect turbine power production. Similar analysis will be performed using much larger turbines to examine how the physics discovered here scale with turbine size so that the extrapolation of the results to full-scale wind farms can be better understood.