Multidisciplinary design optimization of a compact highly loaded fan

The recent progress in Multidisciplinary Design Optimization (MDO) enables engineers to revise design strategies and to address more complex problems. In this paper, the full design of a compact highly loaded fan for aerospace applications is considered. The design comprises several conflicting objectives, such as aerodynamic efficiency and structural integrity. Optimization techniques are applied at every stage of the design, leading to a reduced and accelerated overall process and an enlarged design space. Performance of the machine are first evaluated by through-flow modeling (low-fidelity radial distributions based on experimental correlations) to determine an optimal flow path configuration. High-fidelity aero-mechanical performances are then considered to generate the detailed design of the rotors, including section profiles along the span, as well as lean and sweep. The multi-objective algorithm enables one to consider simultaneously Computational Fluid Dynamics (CFD) and Computational Structural Mechanics (CSM). The methodology is applied to the design of a compact highly loaded fan achieving a 2.1 pressure ratio with an efficiency of 88 % while satisfying the mechanical constraint of titanium with a safety margin of 32 %. The proposed approach allows to generate an original configuration with a reduced time to market.