The scattering of blade boundary layer pressure fluctuations into acoustic waves at the trailing edge, also called trailing-edge noise, is of primary interest to the aerospace/marine industry as it is the main contribution to broadband self-noise for a subsonic fan.
The classical theory for self-noise from an open rotor is based on the theory for a single stationary blade in a uniform subsonic mean flow. In this talk, I will show how the single blade problem can be recast into a wave scattering problem, and solved analytically using some tools of diffraction theory.
The first part of the talk will be focused on the use of Mathieu functions to study the diffraction from finite slits and strips including a comparison with other methods (modified Wiener-Hopf technique). In the second part, I will show how this can be applied to unsteady thin aerofoil theory.