Abstract
A feedback control system for mitigating periodic flow separation on the NACA0024 airfoil was constructed by using string-type dielectric barrier discharge plasma actuators(string-type DBD-PAs) and fiber Bragg grating flow sensors(FBG-FS). A tangential jet is generated from a string-type DBD-PA placed at 5% chord from the leading edge of the airfoil. An FBG-FS is mounted near root of the cantilever beam interior surface, which detects the vibrations of the cantilever tip forced by wake flow around the trailing edge. The TTL signal to control a HV-RF power supply was output when standard deviations of Bragg wavelength fluctuations(λ_<B'>) are larger than a threshold value(γ), λ_<B'> ≥ γ=0.0028. The durations of flow separation under periodic wall oscillation were significantly reduced by the feedback control system. Tube type DBD-PAs using insulating tubes were also develop to extend utilities of string-type DBD-PAs for practical applications in turbomachineries.
