Abstract:
This article presents aeroelastic analysis of the ERATO blade with double-swept design and an homogenised structure, using both computationally intensive and rapid aerodynamics solvers coupled with a projection-based reduced-order model (ROM) for the structure. The study focuses on investigating the impact of blade flexibility on aerodynamic performance during hover flight, and comparing with experimental data. In terms of modelling, the ROM allows for efficient computation of structural displacements, while capturing the non-linear physics and the complex structural response induced by the double-swept configuration. The aerodynamic analysis incorporates different solvers including among others Computational Fluid Dynamics (CFD) with elsA, Vortex Particle Method (VPM) and Blade Element Momentum Theory (BEMT). This multi-solver approach is employed to assess the capability of fast aerodynamic methods to reproduce the desired flow, coupling properties and flight performance. The coupling methods employed such as field transfers and mesh deformation are rather classical but were adapted. First, results highlight the need of aeroelastic coupled analysis to model the ERATO blade in hover. Second, the VPM is proven to be a valid method for reproducing the studied flight condition offering a good compromise between the computational cost and accuracy. Third, the proposed VPM/ROM coupling is validated with respect to the reference CFD/ROM. Finally, this article contributes to evaluate a wide range of methodologies and to propose an alternative method for predicting the rotorcraft blades performance and for assessing the effect of the aeroelastic coupling on such performance. Future work is needed to characterize in more details the aeroelastic behaviour of the ERATO blades with a realistic structural model for hover and in forward-flight, for which the flow is intrinsically unsteady.