TY - GEN A1 - Hintermüller, Micheal A1 - Keil, Tobias A1 - Wegner, Donat T1 - Optimal Control of a Semidiscrete Cahn-Hilliard-Navier-Stokes System with Non-Matched Fluid Densities N2 - This paper is concerned with the distributed optimal control of a time-discrete Cahn--Hilliard/Navier--Stokes system with variable densities. It focuses on the double-obstacle potential which yields an optimal control problem for a family of coupled systems in each time instance of a variational inequality of fourth order and the Navier--Stokes equation. By proposing a suitable time-discretization, energy estimates are proved and the existence of solutions to the primal system and of optimal controls is established for the original problem as well as for a family of regularized problems. The latter correspond to Moreau--Yosida type approximations of the double-obstacle potential. The consistency of these approximations is shown and first order optimality conditions for the regularized problems are derived. Through a limit process, a stationarity system for the original problem is established which is related to a function space version of C-stationarity. Y1 - 2015 UR - https://opus4.kobv.de/opus4-matheon/frontdoor/index/index/docId/1351 UR - https://nbn-resolving.org/urn:nbn:de:0296-matheon-13516 ER -