Generating unconventional wind flow in an activelycontrolled multi-fan wind tunnel

In this study, an iteration-based method to simulate two typical examples of unconventional wind flow in a multi-fan wind tunnel is described: skewed non-Gaussian turbulence and sinusoidal type transient gust. The air flows are generated by 120 actively controlled fans arranged in a 10 wide by 12 high matrix. Time-varying voltages signals can be imported into the fans' servomotors, then corresponding wind flow can be produced in this wind tunnel. At first, the target wind speeds time series are converted to voltages signals, which are input into the fans' motor next, and then the initial wind flow generated can be measured. Then the wind speeds time series to be input are adjusted according to the differences between the target winds speeds and measured flow speeds. The above procedure is iteratively repeated until the measured wind flow is gradually close to the targets. At last, both non-Gaussian turbulence and transient gust can be simulated with satisfied precision after several iterations.