Real-time Airwake Prediction for Improved Deck-landings (RAPID)

As the cost of flight time has increased over the years and the scope of flight test expanded, the aviation community has long sought the ability to earn “credit” for simulation-based evaluations. Recent advances in computational power and new methods in representing complex dynamic systems has moved the conversation from the theoretical into a question of regulation and implementation. How good is good enough? What must be demonstrated to show sufficient equivalency between the live environment and its simulated representation? An additional challenge is to capture those dynamics properly and in such a way that they are suitable for real-time evaluations as part of a piloted simulation. One area of modeling that has proved elusive has been accurate modeling of the airwake behind a ship when performing rotary-winged shipboard landings. Here, airwake refers to the flow of the air around the ship and to the landing pad and adjacent areas resulting from disturbances caused by the environment and the ship superstructure. As the ship moves though the environment for a given wind condition, flow interactions may cause unsteady airflow. Attempts have been made to perform these kinds of evaluations in simulation but have been limited in fidelity. High-fidelity Computational Fluid Dynamics (CFD) simulations require hours or days to obtain a singular solution and are not at all feasible for real-time piloted simulation. Static windfields are often used in simulation to provide cueing representative of dynamic airwakes in simulation. Adding complexity by making these wakes time-dependent has been shown to create a realistic environment for real-time piloted simulation. However, important aerodynamic effects are not present in one-way coupled simulation such as these. Complex phenomena including recirculation and dynamic ground effect will not be present in the real-time simulation without two-way coupled dynamic air wakes.To address the challenge of implementing a real-time, two-way coupled airwake suitable for piloted simulation, a team led by Systems Technology, Inc. (STI), in collaboration with Georgia Institute of Technology (GT), proposes the Real-time Airwake Prediction for Improved Deck-landings (RAPID) project, wherein the Lattice-Boltzmann Method (LBM) will be coupled with a novel hardware/software framework to enable two-way coupled airwake simulations to be performed in real-time and be suitable for piloted simulation evaluations. This effort will further develop, validate, implement, and test the LBM with the aim to enhance simulation fidelity to support virtual sea trials via its new approach to two-way coupled air wakes. Compared to traditional CFD approaches, the LBM is extremely performant, provides a quick turn-around on full scale flow-field calculations (hours not days), and makes real-time simulation feasible. GT has already demonstrated the approach using a representative scenario with a single main rotor helicopter landing on a ship.