UHBR Open-Test-Case Fan ECL5/CATANA

Valdo Pagès (1) , Pierre Duquesne (1) , Stephane Aubert (1) , Laurent Blanc (2) , Pascal Ferrand (1) , Xavier Ottavy (1) , Christoph Brandstetter (1)

1 LMFA - Laboratoire de Mecanique des Fluides et d'Acoustique
2 LTDS - Laboratoire de Tribologie et Dynamique des Systèmes

Application of composite fans enables disruptive design possibilities but increases 1 sensitivity to multi-physical resonance between aerodynamic, structure dynamic and acoustic 2 phenomena. As a result, aeroelastic problems increasingly set the stability limit. Test cases of 3 representative geometries without industrial restrictions are a key element of an open scientific 4 culture but currently non existent in the turbomachinery community. In order to provide a multi-5 physical validation benchmark representative of near future UHBR fan concepts, the open test case 6 fan stage ECL5 has been developed at Ecole Centrale de Lyon. Design intention was to develop a 7 geometry with high efficiency and a wide stability range that can be realized using carbon fibre 8 composites. This publication aims to introduce the final test case which is currently fabricated and 9 will be experimentally tested. The fan blades are composed of a laminate made of unidirectional 10 carbon fibres and epoxy composite plies. Their structural properties and the ply orientations are 11 presented. To characterise the test case, details are given on aerodynamic design of the whole 12 stage, structure dynamics of the fan and aeroelastic stability of the fan. These are obtained with 13 a state-of-art industrial design process : static and modal FEM, RANS and LRANS simulations. 14 Aerodynamic analysis focuses on performance and shows critical flow structures like tip leakage 15 flow, radial flow migration and flow separations. Mechanical modes of the fan are described and 16 discussed in the context of aeroelastic interactions. Their frequency distribution is validated in 17 terms of resonance risk with respect to synchronous vibration. Aeroelastic stability of the fan is 18 evaluated at representative operating points with a systematic approach. Potential instabilities are 19 observed far from the operating line, not compromising experimental campaigns.

Mots clés: Composite; Aeroelasticity; Flutter; Aeroacoustics

Domaines: Sciences de l'ingénieur [physics]

Valdo Pagès, Pierre Duquesne, Stephane Aubert, Laurent Blanc, Pascal Ferrand, et al.. UHBR Open-Test-Case Fan ECL5/CATANA. International Journal of Turbomachinery, Propulsion and Power, 2022, 7 (2), ⟨10.3390/ijtpp7020017⟩. ⟨hal-03765815v1⟩