Singularity functions at axisymmetric edges and their representation by Fourier series
Bernd Heinrich · Mathematical Methods in the Applied Sciences · 1993
Abstract The regularity of solutions of the Dirichlet problem for the Poisson equation in three‐dimensional axisymmetric domains with reentrant edges is studied by means of Fourier series. The decomposition of the 3D problem into variational equations in 2D, a priori estimates of their solutions, a theorem of Riesz–Fischer type and two singularity functions (of tensor and non‐tensor product type) are given.