Prediction and Active Control of Flow-Induced Weapons Bay Acoustics

The modeling and active control of the resonant interaction between a free shear layer and an open cavity is of direct relevance to military aircraft applications. Techniques will be investigated to first model and then control acoustic resonance in open cavity flows. The problem consists of the nonlinear interaction between a turbulent free shear layer and the cavity acoustics and is further complicated by the reattachment geometry and the acoustic receptivity of the separating shear layer. This problem focuses on first developing an accurate yet computationally inexpensive physical model and then actively minimizing the cavity acoustic levels by modifying the shear-layer characteristics with actuators controlled by a neural network. This approach is innovative in both the development of a previously nonexistent dynamic model and application of actuators and neural network-based controllers to the flow-induced weapons bay acoustic problem. The effort, while specifically targeting a weapons bay, is also generally aimed to any flow separation problem exhibiting intersection between a free shear layer and an open cavity.