Maximum principle and gradient bounds for stationary solutions of the Navier-Stokes equations; a computer aided approach

PDE Seminar
Thursday, December 11, 2008 - 15:15
1.5 hours (actually 80 minutes)
Skiles 255
Stanford University
We calculate numerically the solutions of the stationary Navier-Stokes equations in two dimensions, for a square domain with particular choices of boundary data. The data are chosen to test whether bounded disturbances on the boundary can be expected to spread into the interior of the domain. The results indicate that such behavior indeed can occur, but suggest an estimate of general form for the magnitudes of the solution and of its derivatives, analogous to classical bounds for harmonic functions. The qualitative behavior of the solutions we found displayed some striking and unexpected features. As a corollary of the study, we obtain two new examples of non-uniqueness for stationary solutions at large Reynolds numbers.