A predictive controller for the Mach number in a transonic wind tunnel

The use of the unified predictive controller in controlling the Mach number of a transonic wind tunnel is examined. It is shown, by means of simulations and experiments, that the unified predictive controller yields an overall performance improvement of 30-60% in comparison with the proportional-integral-derivative (PID) controller that is normally used to control the Mach number. The rejection by the unified predictive controller of disturbances caused by changing the angle of attack is a factor of four better than that for the PID controller. This makes it possible to change the angle of attack faster, so that the efficiency of the wind tunnel operation can be improved. It is believed that this is mainly due to the fact that knowledge about the disturbances can be incorporated into the predictive controller design. Simulations have shown that even better results can be expected; the results have not yet been verified by experiments.<>