Numerical solution of parametrized Navier-Stokes equations by reduced basis methods

MOX 88

Numerical solution of parametrized Navier-Stokes equations by reduced basis methods

Sunday 24th September 2006

Quarteroni, Alfio; Rozza, Gianluigi

We apply the reduced basis method to solve Navier-Stokes equations in parametrized domains. Special attention is devoted to the treatment of the parametrized non-linear transport term in the reduced basis framework, including the case of non-affine parametric dependence that is treated by an empirical interpolation method. This method features (1) a rapid global convergence owing to the property of the Galerkin projection onto a space W_N spanned by solutions of the governing partial differential equation at N (optimally) selected points in the parameter space, and (2) the off-line/on-line computational procedures which decouple the generation and projection stages of the approximation process. This method is well suited for the repeated and rapid evaluations required in the context of parameter estimation, design, optimization, and real-time control. Our analysis focuses on: (i) the pressure treatment of incompressible Navier-Stokes problem; (ii) the fulfillment of an equivalent inf-sup condition to guarantee the stability of the reduced basis solutions. The applications that we consider involve parametrized geometries, like e.g. a channel with curved upper wall or an arterial bypass configuration.