Flight Tests and Simulations of H175 Low-Speed Rotor-Fuselage Interactions
摘要
This paper validates full-helicopter unsteady simulations against in-flight measurements for an Airbus Helicopters H175 PT1 rotorcraft equipped with a 5-bladed Spheriflex® rotor. We compared numerical results across various low-speed flight conditions (0 to 60 kt true airspeed, and out of ground effect). Employing a single-rotor loose coupling approach between Computational Structure Dynamics (CSD) and Computational Fluid Dynamics (CFD) with six-degrees-of-freedom trim, our results highlight the critical importance of blade elasticity for rotor characteristics and the challenges in modeling the H175 Spheriflex® rotor inter-connected lead-lag dampers. Our simulations strongly align with flight-test data, particularly for critical metrics like main-rotor collective pitch, airframe attitude, rotor power, and pitch-link dynamic loads, validating the model across varying low airspeeds. This agreement persists despite modeling simplifications, suggesting unmodeled effects are marginal. Numerical analyses also reveal insights into airframe download distribution and its evolution with speed, notably capturing a non-straightforward local increase around 30 − 40 kt, aligning with the pitch-up phenomenon. This study not only validates simulation results with unique flight data for a modern rotorcraft but also provides valuable high-fidelity data to enhance helicopter performance prediction, design, and inform the development of lower-fidelity models for both industrial and academic applications. Portions of this work were presented at the