State-Space Free Vortex Wake For Flight Mechanics: A Comparative Study With Glauert And Pitt-Peters Inflow Models

Abstract

This paper evaluates several rotor inflow models with a focus on the State-Space Free Vortex Wake (SSFVW) model for rotorcraft flight mechanics applications. An articulated rotor based on the UH-60 configuration was implemented using the Helicopter Rotor Simulation (HeRoS) framework in MATLAB/Simulink, employing blade element theory with aerodynamic and inertial coupling. Three inflow models named Glauert, Pitt-Peters, and SSFVW, were assessed through steady-state, trim, and gust response simulations under various flight conditions. Results show that Glauert and Pitt-Peters models capture general aerodynamic trends efficiently, making them well-suited for rapid analysis and control design. In contrast, the SSFVW model provides enhanced fidelity, accurately resolving unsteady wake dynamics and their influence on rotor performance, especially in gusty or maneuvering conditions. Although more computationally intensive, SSFVW demonstrates strong potential for real-time or control applications through further optimization techniques. These findings highlight the trade-offs between fidelity and efficiency and support the ongoing integration of advanced inflow models into rotorcraft simulation frameworks.