Real-Time Coupled Ship–Rotorcraft Interactional Simulations Using GPU-Accelerated Lattice-Boltzmann Method

Many traditional ship–rotorcraft interactional simulation approaches, including those used for pilot training, use a one-way coupling between aerodynamics and flight dynamics. In a one-way coupled method, the standalone ship airwake is superimposed on the rotor, modifying its inflow. However, because the rotor wake does not alter the ship airwake and is unaffected by the ship landing deck or superstructure, one-way coupling may not capture all relevant phenomena. To capture important interactional aerodynamic phenomena such as dynamic ground and wall effects, two-way fully coupled simulations may be needed. In this study, one- and two-way coupled real-time and near-real-time simulation models of the ship–rotorcraft problem were developed using a GPU-accelerated lattice-Boltzmann method (LBM) flow field solver. Comparing flow fields and rotor hub loads, the two-way coupled simulations showed good agreement with the new ship–rotor experimental data from Georgia Tech. Real-time full-scale rotorcraft ship approach maneuvers of a notional UH-60A landing on the NATO Generic Destroyer were conducted using a flight controller, and the results showed significant differences in flight control inputs between one- and two-way coupling methods. On the other hand, the presence of ship motion was found to have little effect on the control inputs. The study proved the feasibility of real-time fully coupled ship–rotorcraft flow field simulations at full scale, achieving real-time performance on a single GPU node, and it paves the way for fully coupled LBM pilot-in-the-loop flight simulation trials.