Improving Wind Tunnel “1-cos” Gust Profiles
Davide Balatti, Hamed Haddad Khodaparast, Michael I. Friswell, Μαρίνος Μανωλέσος
Abstract
A vane-type gust generator has been designed and characterized in the Swansea University wind tunnel to enable the validation of the response of aircraft models to gust loads. The experimental results reveal the complexity of the flow between the gust vanes and the aircraft model location. Previous studies have shown that generating a predetermined gust profile at the desired location in the wind tunnel is a challenging problem. In this work, two techniques to improve the “1-cos” gust have been considered. In the first case, the transfer functions between the vane rotation and the gust produced at the aircraft model location have been identified, and its inverse has been used to calculate the vane rotation. The strong aerodynamics nonlinearity limits the improvements of this method. A parametric study on vane rotation has shown that a more complicated vane rotation function made it possible to obtain “1-cos” gusts at the aircraft model location with a mean square error two orders of magnitude smaller than the initial case. Creating “1-cos” gusts with similar frequency content as the regulations require will help design more efficient gust load alleviation systems.