Dynamic CFD Simulation of Aircraft Recovery to an Aircraft Carrier

Abstract

perform localized mesh correction to restore the quality of the deformed grid surrounding the aircraft. The unsteady aircraft loads provided by these simulations were compared to the Manned Flight Simulator (MFS) aerodynamic model for the same aircraft configuration and airwake velocity profile. This provided a one-to-one comparison of the aerodynamic model used in the MFS with the CFD F/A-18 aircraft model that includes the coupling effects between the aircraft and ship flowfields. The lift force comparisons show a much more rapid increase in lift for the one-way coupled MFS model as the aircraft crosses the flight deck ramp. This demonstrates the differences in the two models, and highlights the importance of modeling the flowfield coupling physics of aircraft/ship recovery operations in manned-flight-simulation environments. I. Introduction Accurate models for the prediction of the dynamic response of an aircraft to a ship airwake are critical to the development of realistic flight simulation tools for aircraft carrier launch and recovery operations. For this simulation environment, the aircraft model is integrated with a ship airwake flowfield such that the aircraft loads are obtained in the presence of the fluctuating, turbulent airwake. Of particular interest is the coupled interaction between the ship and aircraft flowfield in the vicinity of the deck ramp and touchdown areas, as this point in the landing flightpath produces the highest workload for the pilot. Additionally, the degree of coupling between the aircraft and airwake is highest in this location. Currently, the Manned Flight Simulator (MFS) at NAVAIR Patuxent River, MD incorporates a comprehensive real-time simulation model of the F-18 that is comprised of multiple aircraft aspects including the models of the propulsion system, landing gear, avionics, and aerodynamics. Ship airwake models are integrated with the aircraft model using an array of points distributed on the airframe, typically at the nose, tail, aircraft center of gravity, and wingtips. The aircraft model samples the velocities of a stand-alone airwake flowfield at these points to derive aircraft forces and moments from a look-up table generated from wind tunnel/flight test data. Unsteady, turbulent airwake data generated from computational fluid dynamics (CFD) calculations have been integrated with the MFS F-18 model to provide the fluctuating airwake environment through which the aircraft flies 1 .