Title: A Finite Element Gauge-Uzawa Method For the 
       Evolution Navier-Stokes Equations

Speaker: Jae-Hong Pyo, Purdue University

Time and Place: Feb. 13, 3:30pm at REC 307


The Navier-Stokes of incompressible fluids are still a computational
challenge. The numerical difficulty arises from the incompressibility
constraint, which requires a compatibility condition (discrete
inf-sup) between the finite element spaces for velocity and pressure.
Several projection methods have been introduced for time
discretization to circumvent the incompressibility constraint, but
suffer from boundary layers,. They are either numerical or due to
non-physical boundary conditions on pressure. 
We introduce a first
order gauge-Uzawa method for time discretization coupled with a stable
finite elements method for space discretization.  The method is
unconditionally stable, consists of $d+1$ Poisson solvers per time
steps, and does not exhibit pronounced boundary layer effects. We
prove error estimates for both velocity and pressure under realistic
regularity conditions via a variational approach, and illustrate the
perofmance with several numerical experiments.  This work is joint
with R.H. Nochetto.