Simulation of a helicopter-ship dynamic interface using offline database of atmospheric turbulence-modified airwake

In the present work, the influence of a neutral atmospheric boundary layer (ABL) on a one-way coupled dynamic interface simulation is evaluated. The effort is performed in the context of time-accurate large-eddy simulations of the Simple Frigate Shape 2 (SFS2) geometry, which is immersed in realistic resolved atmospheric turbulence inflow. Several baseline, uniform inflow, cases are used which are based on the traditional approach of modeling the incoming wind as a constant, uniform inflow. In comparison to the baseline, it is observed that the velocities in a ship airwake are considerably different when formed from an ABL. The unsteady computational fluid dynamics (CFD) solution is then saved as a database and used as inflow to a flight dynamics component of the framework, characterizing the one-way couple nature. Landing approaches and hover cases are evaluated and it is found that the large scales present in the ABL disturb the helicopter notably. The disturbances result in increased controls input and aircraft movement. Analyzing the increased stick movement in the frequency domain, results suggest that the ABL impacts the 0.1-3 Hz stick controls, which comprise the frequency range known to affect pilot workload. The goal is to perform a first evaluation on what additional effects a resolved ABL exerts on the workload, and what is necessary to be modeled in a high-fidelity pilot-training simulator.