Extremum Seeking Control Applied to Airfoil Trailing-Edge Noise Suppression

Extremum seeking control (ESC) and its slope generalization are applied in a high-fidelity flow simulation framework for reduction of acoustic noise generated by NACA0012 airfoil. Two Reynolds numbers studied which different generation mechanisms excited. For low number flow, the scattering vortex shedding at airfoil trailing edge produces tonal noise, while moderate case, boundary-layer instabilities scatter edge, leading to emission multiple tones superimposed on broadband hump. Different setups investigated, they configured either find an optimal steady actuator intensity or position blowing/suction device. Implementation details discussed regarding modules design digital filters. Analyses physical phenomena as well relevant behavior actuated plant conducted understand how extremum loop leverages physics noise. Depending configuration setup, results demonstrate that ESC can provide considerable reductions.