Integrated Bidirectional Thermofluid–Structural Interaction for Multi-Objective Optimization of Transonic Centrifugal Impellers

Centrifugal impellers are critical components in turbomachinery, where performance and reliability are challenged by complex multiphysics interactions under transonic conditions. Existing design methods often neglect thermo–structural interactions, resulting in compromised accuracy and safety. This study addresses these limitations by proposing a multiparameter optimization framework integrating bidirectional thermofluid–structural interaction (BTFSI) analysis to simultaneously enhance aerodynamic efficiency and structural integrity. A BTFSI numerical model was developed, incorporating blade heat transfer and deformation feedback, and applied to optimize five key parameters: blade material, thickness, count, tip clearance, and profile. Results demonstrate that optimized carbon fiber blades reduce maximum stress by 74% and deformation by 61.7% compared to traditional stainless steel, while achieving a 1.1% increase in polytropic efficiency and 0.76% higher pressure ratio. The framework resolves interdisciplinary contradictions between aerodynamic performance and structural safety, offering a validated methodology for transonic impeller design. This work advances high-speed turbomachinery optimization by balancing multiphysics interactions, providing critical insights for material selection and performance enhancement in energy-intensive applications.