Two-Way Coupled V/STOL Operation in Ship Airwakes with Atmospheric Turbulence

The present work develops a computational framework for simulating the two-way coupled ship-helicopter dynamic interface using large-eddy simulation. The Simple Frigate Shape 2 geometry is modeled using the immersed boundary method, and baseline simulations under both uniform inflow and neutral atmospheric boundary layer (ABL) conditions are validated against wind tunnel measurements for two wind-over-deck angles. Rotor modeling techniques, including the actuator line model (ALM) and actuator disk model (ADM), are verified and validated across several configurations: the Knight and Hefner rotor, ONERA HAD-1 propeller, and NASA Dragonfly Phase B* coaxial rotor. The lower-fidelity ADM captures wake characteristics consistent with the ALM with up to a 9× speedup. The ADM maintains strong agreement with experimental and numerical results for integrated performance metrics and is suitable for two-way coupled simulations. The developed framework is applied to a rotor-obstacle configuration based on a GARTEUR 22 experimental survey and subsequently to a fully-coupled ship-rotor-ABL system.