Modeling and Simulation of Hose-Paradrogue Aerial Refueling Systems

A dynamic modeling and simulation analysis of hose-paradrogue aerial refueling systems is presented. A set of governing equations of motion is derived using a finite-segment approach that describes the dynamics of the hose-paradrogue assembly under a prescribed motion of the tanker. The hose is modeled by a series of ball-and-socket-connected rigid links subject to gravitational and aerodynamic loads that account for the effects of tanker wake, steady wind, and atmospheric turbulence. Numerical simulations show a good correlation of the model's steady-state characteristics with previously reported flight-test data. Also investigated are the dynamic characteristics of the paradrogue assembly resulting from atmospheric turbulence and a typical pitch doublet maneuver of the tanker. Finally, the dynamic motion resulting from an in-flight adjustment of the paradrogue drag associated with strut-angle changes is studied.