title: The effect of acoustic forcing on an airfoil tonal noise mechanism.
abstract: The response of the boundary layer over an airfoil with cavity to external acoustic forcing, across a sweep of frequencies, was measured. The boundary layer downstream of the cavity trailing edge was found to respond strongly and selectively at the natural airfoil tonal frequencies. This is considered to be due to enhanced feedback. However, the shear layer upstream of the cavity trailing edge did not respond at these frequencies. These findings confirm that an aeroacoustic feedback loop exists between the airfoil trailing edge and a location near the cavity trailing edge.
authors.affiliation: School of Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia karn.schumacher@adelaide.edu.au, con.doolan@adelaide.edu.au, richard.kelso@adelaide.edu.au.
authors.forename: Karn L
authors.initials: KL
authors.lastname: Schumacher
authors.affiliation: School of Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia karn.schumacher@adelaide.edu.au, con.doolan@adelaide.edu.au, richard.kelso@adelaide.edu.au.
authors.forename: Con J
authors.initials: CJ
authors.lastname: Doolan
authors.affiliation: School of Mechanical Engineering, The University of Adelaide, Adelaide, South Australia 5005, Australia karn.schumacher@adelaide.edu.au, con.doolan@adelaide.edu.au, richard.kelso@adelaide.edu.au.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Kelso