Inverse boundary value problem for the Stokes and the Navier-Stokes   equations in the plane
  In this paper, we prove in two dimensions global identifiability of the viscosity in an incompressible fluid by making boundary measurements. The main contribution of this work is to use more natural boundary measurements, the Cauchy forces, than the Dirichlet-to-Neumann map previously considered in \cite{IY} to prove the uniqueness of the viscosity for the Stokes equations and for the Navier-Stokes equations. 
Ru-Yu Lai, Gunther Uhlmann and Jenn-Nan Wang
math.AP