Coupled Fluid–structure Interaction Simulation of Aerodynamic Load Fluctuations and Fatigue Life in a Centrifugal Fan FN280

Rotating machinery such as centrifugal fans is often exposed to unsteady aerodynamic loads that can induce fatigue damage during prolonged industrial operation. This study investigates the fatigue life of a centrifugal fan (FN280) used in a cement plant through a one-way fluid–structure interaction (FSI) approach. Transient aerodynamic loads were computed using ANSYS Fluent and subsequently transferred to ANSYS Mechanical for structural fatigue analysis. Since the original fan geometry was unavailable, a detailed three-dimensional model was reconstructed via reverse engineering to ensure accurate aerodynamic representation. The unsteady numerical simulations were performed under four operating conditions and validated against experimental performance data. The comparison shows a satisfactory level of agreement, confirming the reliability of the adopted modelling approach. Simulation results indicate that most regions of the fan exhibit fatigue safety factors between 1 and 15, suggesting generally safe operation. However, localized stress concentrations near the blade root and shaft–disc junction display safety factors slightly below unity, indicating potential sites for early fatigue crack initiation. The estimated fatigue life is approximately 2.8 × 10⁶ cycles, emphasizing the significance of accounting for aerodynamic loading effects in fatigue assessment. Overall, the study demonstrates the capability of FSI-based numerical simulations for predictive maintenance and reliability evaluation, while further experimental validation is recommended.