Abstract

When Modelling sound attenuation in jet engines an impedance boundary condition is used to capture the effects of acoustic liners. To keep this boundary condition simple in form one can consider a sheared flow profile with no slip at the boundary. Doing so however gives rise to a regular singularity of the Pridmore-Brown Equation known as the Critical Layer.

This talk will give an outline of one way in which the critical layer may be considered. We will then focus on the specific case of a mean flow profile of a uniform flow with a quadratic boundary layer. We will both be drawing comparisons to previous literature and examining behavior that had been previously hypothesised to not be able to occur. In particular we will see that this behaviour is commonplace, and results in previous unseen importance of the critical layer on the far-field.