Singularities of a compressible Stokes system in a domain with concave edge in

We study a compressible Stokes system in a three dimensional domain with a concave edge. We subtract an edge singularity from the velocity and show an increased regularity for remainder after the singular function has been subtracted. We give a formula for the edge singularity in terms of an “edge flux intensity function.” Using the transport character of the continuity equation we show a propagation of the edge singularity into the domain.