Two-Way Blade Modeling Method for Structural Redesign of Compressor Blades

Over the past few years, stringent environmental requirements and the need for increased overall efficiency have forced designers to bring turbomachine components closer to their operating limits. To address lifespan issues, costly redesign operations are thus unavoidable. These operations face many roadblocks, especially when they are triggered by nonlinear phenomena for which there exists no design guidelines. For aircraft engine blades, the handling of nonlinear structural interactions is a major challenge. This works proposes a proof of concept for the redesign of compressor blades undergoing structural contact interactions at the blade-tip/casing interface. The redesign process involves the modeling of an existing input blade, followed by a shape update based on an iterative optimization algorithm. A two-way modeling method is proposed to parameterize the input blade and generate a computer-aided design model from blade parameters describing several conical blade sections. The fidelity of the parameterized blade with respect to the input blade is assessed for the NASA blades rotor 37 and rotor 67. A high fidelity is observed with respect to geometric and dynamic characteristics. The modeling method is fully compatible with an iterative redesign process: it is applied to the redesign of rotor 37 to increase its robustness to contact interactions.