Designing, Manufacturing, and Testing a Wind Gust Generator

Abstract

A two-vane wind gust generator has been designed, manufactured, and tested at the Arizona Low-Speed Wind Tunnel at the University of Arizona to meet the regulations defined in the FAR and CS by the FAA and EASA respectfully. A gust generator is a necessary feature for a wind tunnel because the response of a system can be analyzed when it is introduced to specific gusts parameters. Wind gusts change the pressure distribution over a body and cause the greatest aerodynamic structural loads on an aerial vehicle. Commercial aircraft use gust load alleviation systems to alter the pressure distributions around their wings to ultimately reduce any stress on the root of the wing. So, testing these systems in a controlled wind tunnel environment is beneficial for their optimization. In addition, there is an increasing interest in air vehicles for planetary exploration with numerous rotor and fixed wing aircraft being proposed in light of the accomplishments from the Ingenuity helicopter. Therefore, to increase airframe reliability under varying environments, it is important to consider the aeroelastic effects because they affect the aerodynamic performance, maneuverability, and control of an aerial vehicle. Previous gains in literature determined the best possible configuration for a wind gust generator, which was a two-vane configuration, and also established a technique to improve the discrete gust profile. Theresearch throughout this paper was aimed at designing a wind gust generator to fit the dimensions in the wind tunnel, conducting hot-wire measurements to quantify the generated gust, enhancing the discrete gust profile, classifying the enhanced discrete gust, and creating an input to output algorithm to generate specific gusts for future models. Overall, this wind gust generator was capable of creating the “1-cos” gust profile modeled by aviation authorities and able to obtain governing equations for a servomotor input to gust response output relationship. This wind gust generator was designed for a motor frequency up to 20 hertz and a motor amplitude up to 20 degrees. The work presented in this thesis is for a maximum motor frequency of 10 hertz, a maximum motor amplitude of 10 degrees, and a maximum tunnel velocity of 25 m/s.