Turbulent flows and UAV flight test with fan array wind tunnel

The low-level Atmospheric Boundary Layer (ABL) with unsteady wind and gust is a common, but challenging working condition for general aviation and Micro Aerial Vehicle (MAV) flights. To better understand the aircraft flight performance within such environment, an open wind tunnel, which not only can offer space for aircraft free-flight experiments, but also can generate turbulent flow with desired characteristics, is an ideal tool. A Fan Array Wind Tunnel (FAWT) can easily fulfill these two requirements. By changing the RPMs of the fans in certain locations of FAWT, one can obtain accustomed turbulent profiles with different characteristics for MAV flights. In this research, an FAWT is utilized in an indoor autonomous flight lab to generate certain turbulent flow profile and the flight control performances of the MAV are recorded by the motion capture system. The spectral and spatial characteristics of different turbulent profiles are obtained by a pressure transducer and a hotwire probe. The relaionship between turbulence characteristics and corresponding MAV flight control performances are investigated.