Full Design of a Highly Loaded Fan by Multi-Objective Optimization of Through-Flow and High-Fidelity Aero-Mechanical Performances

Abstract

An innovative design methodology for axial flow compressors is developed utilizing a multi-objective optimization. The full design of a highly-loaded fan is considered, including through-flow and high-fidelity performance evaluations. To augment the explored design space and smoothen the whole process, optimization techniques are integrated into the different steps in the design. As an alternative to the traditional parametric studies performed for the flow path design, an optimization of the through-flow configuration is performed to initiate the aerodynamic design of the fan. To bypass two-dimensional sub-optimal results, the detailed design of the fan rotor geometry is then directly processed with a three-dimensional optimization, including several section profiles along the span, as well as lean and sweep. The multi-objective algorithm enables one to consider fluid and structure performances simultaneously. High-fidelity CFD (Computational Fluid Dynamics) and CSM (Computational Structural Mechanics) methods are used to guarantee the flow efficiency and the structural integrity of the finalized design. This methodology is applied to the design of a transonic fan achieving a pressure ratio of 2.1.