“…The state variables are supposed to satisfy the underlying fluid mechanical equations, and there are typically further constraints, e.g., bilateral constraints on the design variables which restrict the shape of the fluid filled domain. Shape optimization problems have been extensively studied and are well documented in the literature (cf., e.g., the monographs [1,16,31,33,58,59,81,87,94] ). The traditional approach relies on a separate treatment of the design objective and the state equation by an iterative cycle that starts from a given design, computes an approximate solution of the state equation for that design, invokes some sensitivity analysis for an update of the design, and continues this way until convergence is achieved.…”