Wind Tunnel Generated Turbulence

Abstract

Research on the interaction of gusts and turbulence on aerodynamic forces has started at the University of Florida Aerodynamic Characterization Facility located at the Research and Engineering Education Facility. The objective of this research is to characterize the turbulent flow behind a newly developed active turbulence grid so that future research utilizing the grid to assess the effects of turbulence on aerodynamic forces may be accomplished. The research utilizes an active turbulence grid based on designs first implemented by Makita to generate adjustable turbulent flow fields. In this paper the active turbulence grid is designed, constructed, controlled, and initially tested using hot-wire anemometry. Testing identified dependence of turbulence statistics on forcing protocol as well as changing behavior downstream. The active turbulence grid was shown capable of generating turbulence from 12 to 30 % root mean square intensity as well as generating turbulence with isotropy ratios ranging from 1 to 1.35. The length scales generated by the active turbulence grid were on the order of 0.25 m, and there was the desired variability due to changing motion profile. These initial tests indicate that the active turbulence grid has met its design parameters, opening the way for future testing.