Implementation and validation of a delta-airload method to enhance rotor blade CFD/CSD prediction capability

Abstract

Aeroelastic deformation significantly affects the aerodynamic performance, vibration, noise, stability, and fatigue characteristics of rotorcraft. Accurate prediction technology is essential for the development of next-generation rotorcraft. This paper presents recent progress in aeroelastic analysis technology. The delta-airload method is implemented into the rotorcraft CFD/computational structural dynamics (CSD) solver rFlow3D developed by the authors. In the coupled analysis, aerodynamic forces are initially evaluated using blade element theory (BET), and the delta airload between the BET and CFD aerodynamic forces is employed for CFD/CSD coupling. Validation studies are conducted using HART II workshop data, and rotor aerodynamics, elastic deformation, and noise characteristics are compared with experimental measurements. The numerical results show reasonable agreement with the experimental data.