A new gust generator for a low speed wind tunnel: Design and commissioning

An artificial gust generator system has been developed for the University of Bristol Large low speed Wind Tunnel. This paper covers the design, manufacture, and initial testing. The system comprises two horizontal NACA-0015 gust vanes placed upstream of the working section. Two independent servo-motors are used to simultaneously rotate the vanes causing the airflow to be deflected, resulting in a temporary change in the angle of attack of the free-stream in the working section. The gust vanes are a carbon fibre composite construction, and were designed using FE analysis to place the first natural frequency above the desired maximum operating frequency of 20 Hz. Initial experimental data, collected from a cobra probe, indicates the system is reliably capable of creating gusts with amplitudes up-to 10°. The experimental data is also compared to CFD simulations which were performed as part of the design trade studies. The CFD uses overset meshing methods to accurately model the motion of the gust vanes and the trailing wakes.