Design and Modeling of an eVTOL Semipassive Ice Protection System

Atmospheric icing degrades rotorcraft performance and safety. Electric vertical takeoff and landing (eVTOL) vehicles are typically not designed for adverse weather and lack ice protection. Ice accretion on rotor blades increases aerodynamic drag, raising current draw; without adequate cooling, motors can fail, and controllers have exceeded 200°C. Building on these observations, this study develops and evaluates a semipassive, low-power ice-protection system that utilizes motor waste heat and uses centrifugal forces to drive air through a small leading-edge duct. Wind-tunnel tests characterize leading-edge temperature distributions. CFD predictions are verified against wind-tunnel measurements. A closed-form expression estimates rotation-induced internal mass flow. A parametric conjugate heat transfer model for a Joby S4 rotor blade determines minimum inlet temperatures and flows required to maintain the surface temperature above [Formula: see text] in dry air conditions. Results indicate that centrifugal pumping alone can extract air but may be insufficient to deice at practical temperatures; adding a compact fan or external device substantially lowers the required temperature. Required temperature decreases as supplied flow increases, defining a clear design trade space. Guidance recommends maximizing inlet mass flow or available temperature within electrical limits, prioritizing duct diameter and rotational speed to strengthen centrifugal effects, and incorporating low-power assistance when thermal margins are tight. This framework supports safer eVTOL operations during icing conditions.