Simulation of helicopter shipboard launch and recovery with time-accurate airwakes

A simulation of the helicopter/ship dynamic interface has been developed and applied to simulate a UH-60A operating from a landing helicopter assault (LHA) class ship. Steady and time-accurate inviscid computational-fluid-dynamics (CFD) simulations are performed over a full-scale LHA class ship using the parallel flow solver PUMA2 to predict the unsteady vortical ship airwake. Time-accurate CFD solutions of the LHA airwake are interfaced with a flight dynamics simulation based on the GENHEL model. The flight dynamics model was updated to include improved inflow modeling and gust penetration effects of the ship airwake. An optimal control model of a human pilot was used to simulate pilot control activity for a specified approach and departure trajectory. The pilot model was designed so that the tracking performance could be tuned based on a desired crossover frequency in each control axis. Results show that the unsteadiness of the ship airwake has significant impact on pilot workload when the helicopter is operating near the deck and superstructure of the ship.