Nonlinear Cascade Fuzzy Control of a Water Droplet Generator in an Subsonic Icing Wind Tunnel

Droplets generation in wind tunnels plays a crucial role in studying the factors contributing to ice formation on aircrafts. The liquid water content (LWC) and median volumetric diameter (MVD) are critical parameters influencing ice formation due to their impact on the rate of ice accumulation (frost, icing, or mixed), significantly affecting aircraft performance. Controlling these parameters is therefore essential when designing a test bed for characterizing systems sensitive to ice formation. In this paper, a nonlinear cascade fuzzy control structure is employed to control both the LWC and MVD obtained with a system injecting a mix of air and water in a refrigerated wind tunnel. This wind tunnel is purposed to accommodate the aforementioned systems to characterize. The desired values for MVD and LWC are used to determine setpoints for the water and air flows through the injection system. These setpoints serve as inputs for an internal control loop, where a PI controller is used to adjust the injector’s valves’ opening and control the flows. The efficiency of the proposed control is illustrated through simulation results.