This talk is concerned with a topology optimization approach for multi-physics applications which rests on an explicit meshed discretization of the boundaries and interfaces, at every iteration of the optimization process. Typical applications are coupled fluid-solid-thermal system of equations and in particular fluid-to-fluid heat exchangers. The proposed framework combines several recent techniques from the field of shape and topology optimization, and notably a level-set based mesh evolution algorithm for tracking shapes and their deformations, an efficient optimization algorithm for constrained shape optimization problems, and a numerical method to handle a wide variety of geometric constraints such as thickness constraints and non-penetration constraints. Our strategy is applied to the optimization of various types of heat exchangers or weakly coupled fluid-structure systems. A first example is a simplified 2D cross-flow model where the optimized boundary is the section of the hot fluid phase flowing in the transverse direction, which is naturally composed of multiple holes. A minimum thickness constraint is imposed on the cross-section so as to account for manufacturing and maximum pressure drop constraints. A second example is the design of 2D and 3D heat exchangers composed of two types of fluid channels (hot and cold), which are separated by a solid body. A non-mixing constraint between the fluid components containing the hot and cold phases is enforced by prescribing a minimum distance between them.
This is a joint work with C. Dapogny, F. Feppon and P. Jolivet.