Model-free adaptive flow control of simulated smoke for airworthiness certification of smoke detectors in aircraft cargo compartments

In airworthiness certification tests for smoke detectors in aircraft cargo compartments, controlling the flow field of simulated smoke to approximate that of actual fire smoke is necessary. However, in existing research on simulated smoke flow control, the evaluation of actuation schemes has predominantly focused on their ability to regulate smoke concentration, with a notable lack of assessment regarding their capacity to modulate the smoke velocity field. This oversight has left an actuation scheme without a corresponding fluid mechanics-based explanation. Furthermore, the complexity of turbulent flow fields in simulated smoke scenarios poses considerable challenges in designing control laws based on precise models. To address these challenges, this study first used particle image velocimetry measurement technology to uncover quantitatively the evolutionary patterns of the simulated smoke velocity field under two distinct actuation schemes based on a flow control experimental platform for simulated smoke. This approach ultimately determined the optimal actuation scheme for the feedback flow control of simulated smoke. Additionally, by integrating model-free adaptive control with virtual reference feedback tuning, we achieved a purely data-driven design and parameter tuning of feedback control laws for simulated smoke concentration, and the simulated smoke concentration can effectively track the smoke concentration in actual fire. Furthermore, the evolution pattern of the velocity field during the feedback control of simulated smoke concentration was measured, and the results of the concentration feedback control were explained accordingly. The proposed feedback flow control method of simulated smoke can be used in airworthiness certification of smoke detectors in aircraft cargo compartments.