Sensitivity Of Inflow Determination Techniques For Rotor-Blade Actuator Line Models

Abstract

As part of a US-France Project Agreement, the US Army and ONERA are investigating mid-fidelity computational approaches for rotorcraft aerodynamics. The approaches from both groups use immersed boundaries instead of boundary-layer-resolved fuselage/hub meshes and actuator lines in the place of rotor blades. The current work focuses on the methodology used in the actuator line model to extract velocities from the background flowfield and the capability of such model to accurately capture Blade Vortex Interactions (BVI). An isolated three bladed rotor is first used to investigate different velocity sampling methods. Following that, an improvement to the actuator line model is explored in order to better capture the tip loads and BVI. In the final application, model improvement is validated on the Dauphin 365N configuration in forward flight.