Open-Loop Higher Harmonic Control Simulation by Tightly Coupled Actuator Line Method / Computational Structural Dynamics

This paper presents a higher harmonic control (HHC) simulation by using a coupled actuator line method (ALM) and computational structural dynamics (CSD) framework. The ALM is implemented within an in-house computational fluid dynamics (CFD) solver based on a compressible large-eddy simulation (LES) approach DYMORE, a multibody dynamics software, is utilized as the CSD solver. The proposed framework is validated by the trim analysis of UH-60A rotor system under the Flight Counter 8513 flight condition, which represents a lower-speed forward flight maneuver. Using such trimmed state as a baseline, comprehensive HHC simulations of the UH-60A rotor will be executed. The orthogonality and linearity of the HHC input are evaluated, and their control authority over various rotor hub load components is investigated. Furthermore, the effect of the HHC input on the vibratory rotor blade and pitch link loads will be analyzed.