Stable determination of a body immersed in a fluid: the nonlinear   stationary case
  We consider the inverse problem of the detection of a single body, immersed in a bounded container filled with a fluid which obeys the stationary Navier-Stokes equations, from a single measurement of force and velocity on a portion of the boundary. We obtain an estimate of stability of log-log type. 
Andrea Ballerini
math.AP