Dynamic Modeling and Simulation of Hose-Paradrogue Assembly for Mid-Air Operations

Abstract

Presented in this paper is dynamic modeling and simulation analysis of hose-paradrogue assembly for mid-air operations, typically used for aerial refueling. A set of governing equations of motion is derived based on multi-body dynamic modeling framework, which describes the dynamics of the hose-paradrogue assembly under a prescribed motion of a tanker or a towing vehicle. The hose is modeled by a series of ball-and-socket connected rigid links subject to gravitational and aerodynamic load that takes into account the effect of tanker wake. An adjustable drag paradrogue assembly aerodynamic model is considered to investigate the effect of in-flight change of paradrogue drag for the possibility of stabilizing and steering its position relative the tanker over a broad speed range as well as for different types of the tanker motion. Numerical simulations show a good correlation of the steady-state characteristics with the previously reported flight test results. Also investigated are the dynamic characteristics of the paradrogue assembly subject to typical tanker motions; climbing, descending, and phugoid oscillation. Finally, the dynamic motion resulting from in-flight adjustment of the paradrogue drag through its strut angle change is studied. Nomenclature