This text covers the analytical basis of Navier-Stokes equations in irregular domains, which is formed by coercive estimates. These enable proofs to be given of the solvability of the boundary value problems for Stokes and Navier-Stokes equations in weighted Sobolev and Holder spaces, and allow the investigation of the smoothness of their solutions. This, in turn, allows one to deal with the special problems that arise in the presence of edges or angular points in the plane case, at the boundary or noncompact boundaries. Such problems cannot be dealt with in any of the usual ways. This book is intended for graduate students, research mathematicians and hydromechanicians whose work involves functional analysis and its applications to Navier-Stokes equations.