Towards efficient one-shot optimization with unsteady Navier-Stokes equations

18 April 2014
12:00 pm to 1:00 pm
Towards efficient one-shot optimization with unsteady Navier-Stokes equations
Nico Gauger
Visiting Professor
Department of Aeronautics and Astronautics

Prof. Nicolas R. Gauger is a professor in the Computational Mathematics Group,Department of Mathematics and Center for Computational Engineering Science, RWTH.  He will be hosted by Prof. Qiqi Wang until the end of August, 2014.

The one-shot method has proven to be very efficient in optimization with steady partial differential
equations (PDEs). In this approach, the necessary optimality conditions, resulting in
the state, the adjoint, and the design equations, are solved simultaneously. Applications of the
one-shot method in the field of aerodynamic shape optimization with steady Navier-Stokes
equations have shown, that the computational cost for an optimization, measured in runtime
as well as iteration counts, is only 2 to 8 times the cost of a single simulation of the governing
PDE. In this talk, we present a framework for applying the one-shot approach also to optimization
and control problems with the unsteady Navier-Stokes equations. Straight forward
applications of the one-shot method to unsteady problems have shown, that its efficiency depends
on the resolution of the physical time domain. In order to dissolve this dependency, we
consider an unsteady model problem and investigate an adaptive time scaling approach, which
yields the same efficiency as observed for steady problems.