IMPROVED PARALLEL PRECONDITIONERS FOR MULTIPHYSICS TOPOLOGY OPTIMIZATIONS H.U. Akay*, E. Oktay** M. Manguoglu***, A.A. Sivas*** *Department of Mechanical Engineering Atilim University, Ankara, Turkey **EDA Engineering Design and Analysis METU Technopark, Ankara, Turkey ***Department of Computer Engineering Middle East Technical University, Ankara, Turkey 27 th Int. Conf. Parallel Computational Fluid Dynamics, Montreal Canada, May 17- 22, 2015