Numerical and Experimental Icing Simulations of the Next-Generation Civil Tiltrotor Engine Intake

This paper focuses on numerical and experimental icing simulations of the engine air intake of the Next-Generation Civil Tiltrotor (NGCTR). Rotorcraft engines typically exhibit high sensitivity to in-flight and ground icing and must be protected to ensure safe operation. The intake system under investigation features integrated engine protection solutions tailored to the NGCTR application, including an ice protection system (IPS). The system performances in icing conditions were extensively tested and verified in the Rail Tec Arsenal Icing Wind Tunnel (IWT). This paper investigates the characteristics of ice accretion on the dynamic intake scoop operating under unprotected conditions. It presents a comparison between experimental data and numerical simulation results. Aerodynamic effects, based on pressure measurements, are also discussed. The numerical methodology was specifically developed to replicate the conditions of the IWT setup. No prior studies combining both experimental and numerical icing analyses are available for the present intake configuration. A strong correlation between experimental and simulated ice accretion is observed, with accurate predictions of both ice shapes and accretion limits. These findings confirm the critical intake regions identified during the IPS design phase and demonstrate the reliability of the numerical models used, aiming to inform advanced IPS design for the NGCTR air intake. This study was conducted as part of the EU Clean Sky 2 project TRIcEPS.