Numerical Study of Fluid-Structure Interaction of the UHBR ECL5/CATANA Fan

With the increasing use of composite materials in fan blades, the analysis of fluid-structure interaction (FSI) phenomena has become essential to improve both knowledge of flow physics and the influence on performance and stability limits. Experimental test cases become a key element by offering reference data under realistic operating conditions in order to validate advanced CFD methods and fine-tune existing numerical models. As a result, the development of modern fan architecture requires dedicated experimental benchmarks to provide representative geometries. In this context the open-test-case ECL5/CATANA, representative of near-future Ultra High Bypass Ratio (UHBR) architecture, has been designed and experimentally investigated at the Ecole Centrale de Lyon (ECL). An extensive investigation has been conducted on a novel test facility with multi-physical instrumentation, providing a large database of high quality aerodynamic and aeromechanic measurements. In this paper, a thorough numerical study of the fan stage aerodynamics has been performed using the CFD TRAF code developed at the University of Florence. To have a deeper understanding of multi-physics coupling mechanisms, flutter simulations and unsteady runs near stall margin have been performed to characterize self-induced vibration and Non-synchronous vibration (NSV) respectively. This paper aims to evaluate and predict the onset of instabilities driven by fluid-structure interaction. The numerical results are analyzed and compared with experimental data, demonstrating the accuracy of the proposed numerical model.