THREE DIMENSIONAL BVI SIMULATION ON AEROELASTIC BLADES USING A NEW DEFORMING GRID APPROACH COUPLED TO A FREE-WAKE ANALYSIS

This paper presents a new computational method for the simulation of three dimensional Blade-Vortex Interactions on aeroelastic blades. A general interface between a full span free-wake analysis and a 3D Full Potential code is developed. It aims at interpolating the wake in order to accurately simulate the impulsive induced velocity fluctuations responsible for BVI. A deforming grid approach in the Full Potential code is presented in order to be able to treat the case of aeroelastic blades. This new method is applied on several low speed descent flight configurations for tapered or rectangular blades, without and with Higher Harmonic Control of the pitch angle. The BVI peaks appearing on the blade loads are generally pretty well predicted, both in the advancing and the retreating sides of the rotor disk. The pressure distributions are then used in an acoustic code to calculate the noise emitted by the rotor in a plane located under the rotor disk. The agreement with experiment is fair, although some discrepancies are found on the maximum noise levels.