Aeroelastic Load Analysis of the HART-II Rotor Blade using Three-dimensional Solid Finite Element

키워드

확장요약문

Higher harmonic pitch control can reduce rotor vibration and blade vortex interaction noise, but its effects on internal blade stresses require further assessment. This study proposes extending a three dimensional solid finite element aeroelastic framework with the Pitt Peters dynamic inflow model to investigate the HART-II baseline, minimum noise, and minimum vibration conditions. The objective is to evaluate blade aeroelastic responses and determine how these experimentally established control conditions affect sectional stress distributions.

The rotor blade is represented using twenty node hexahedral elements within an updated Lagrangian formulation. Aerodynamic section kinematics are extracted from the deformed solid mesh, and sectional forces and pitching moments are transferred to the structural nodes through equivalent nodal forces. The Pitt Peters model will be incorporated to represent the transient evolution of the mean and first harmonic components of induced inflow in response to rotor loading. The coupled equations are advanced using generalized alpha time integration with Aitken relaxation. Sectional normal and shear stresses are recovered from the three dimensional structural solution.

The three conditions will be evaluated using their corresponding experimental pitch control inputs and a common set of calibrated structural properties. Predicted sectional normal forces, pitching moments, blade tip deflections, and structural moments will be compared with HART-II measurements. The subsequent assessment will examine differences in spanwise and cross sectional stress distributions, peak stresses, cyclic stress amplitudes, and stress concentration locations across the three conditions. Particular attention will be given to whether the minimum noise and minimum vibration settings increase local stress demands or redistribute stresses relative to the baseline condition. The study aims to clarify the structural implications of these control settings and demonstrate the use of three dimensional solid finite elements for evaluating internal blade stresses alongside rotor aeroelastic responses.