Aerial Refueling Tanker and Receiver Aerodynamic Interaction Modeling and Simulation – Software Application

In aerial refueling operations, a heavy, fuel-laden tanker aircraft often operates at a high lift coefficient which imparts significant velocity perturbations upon the downstream flow field.  As the trailing receiver aircraft maneuvers within this tanker wake, it experiences position-dependent aerodynamic force and moment increments that are not negligible and affect its trim and control states. The Navy has operational dependance on aerial refueling and has significant need to improve the simulation fidelity of this flight regime to develop, test, and certify its equipment, aircraft, and procedures in a laboratory environment. In response to this need, a unique application of a classical vortex lattice, aerodynamic modeling method (dubbed “incremental vortex lattice method, IVLM”) was employed to compute tanker-induced force and moment increments from a pre-solved CFD tanker wake velocity field. The use of this computationally compact methodology and simple planar receiver model enables real-time summation of these tanker interference effects onto any existing receiver aerodynamic model without a priori knowledge of that underlying model. Correlation with experimental aerial refueling datasets and pilot-in-the-loop evaluations have shown that the technology effectively models real-world tanker effects and adds valuable fidelity to the simulation. The present study will expand the refinement of the baseline MATLAB/Simulink software toolset, convert it to compiled C++ code, and integrate it directly into the Navy’s CASTLE simulation environment as a configurable/callable module. Subsequently, the toolset will be applied to the high-profile MQ-25 tanker program to model both that tanker and all current carrier-based aircraft that will refuel behind it. Various experimental and computational datasets will provide the wake flow field definition and serve to verify the resulting simulation fidelity.