Effect of boundary-layer shear on trailing-edge noise

© 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. Previous studies have shown that passive devices near the trailing-edge of an aerofoil can greatly reduce noise, though the physical mechanism is unclear. Careful experimental investigation has shown changes to both the profile of the turbulent boundary layer and the position of the turbulence therein. With this in mind, a mathematical model of the effect of boundary layer modification on scattered noise is considered, both numerically and, where possible, analytically. This Wiener-Hopf based analysis, concentrating on the sharp trailing-edge of an aerofoil, can be extended to other mixed boundary value problems. For example, it allows for reappraisal of previous work on junctions between hard and pressure-release walls.