Dynamic Stall Control by Periodic Excitation, Part 1: NACA 0015 Parametric Study

A parametric study was undertaken to investigate the effect of periodic excitation (with zero net mass e ux ) on a NACA0015airfoilundergoingpitchoscillationsatrotorcraftreducedfrequenciesunderincompressibleconditions. Theprimaryobjectiveofthestudywastomaximizeairfoilperformancewhilelimitingmomentexcursionstotypical prestalled conditions. The incidence angle excursions were limited to § 5 deg, and a wide range of reduced excitation frequencies and amplitudes were considered for 0 :33 10 6 < ‐ Re <‐ 0:93 10 6 with various e ap dee ections and excitation locations. Signie cant increases in maximum lift and reductions in drag were attained while containing themomentexcursions. Oscillatoryexcitation wasfoundto befarsuperiortosteadyblowing,which wasevendetrimental under certain conditions, and e ap-shoulder excitation was found to be superior to leading-edge excitation.