Aerodynamic Investigations of Paradrogue Assembly in Aerial Refueling System

Abstract

*† Unmanned Aerial Vehicles (UAVs) are now considered as an integral part of modern military operations. One of challenging issues in the future UAV operations is an autonomous aerial refueling which will raise the current UAV mission boundaries set by vehicle endurance and range limitations. Aerial refueling is considered as a routine procedure for human operators, but for UAV applications it requires high level of autonomous technologies based on the solid recognition of the overall refueling system design principles. In this paper, the aerodynamic characteristics of paradrogue assembly in a hose-drogue-probe type aerial refueling system are investigated through wind tunnel experiments as well as computational fluid dynamic (CFD) analysis. In particular, the drag characteristics of paradrogue assembly upon the geometric changes of its component configuration – struts, canopy – are studied. An empirical model based on the full factorial design analysis is constructed, which allows predicting the drag coefficient of paradrogue assembly corresponding to these configuration changes.