Dynamic Response of Aerial Refueling Hose-Drogue System with Automated Control Surfaces

AbstractThe classical hose-drogue system has been modified by adding an automated control surface (ACS) at the point where the hose is connected to the drogue. This control surface stabilizes the static position as well as improves the dynamic characteristics of the hose-drogue system. The hose is assumed to behave as a tensed cable with no bending forces. Under the assumption that the dynamic response is small compared with the static deformation, linearized expressions for both the perturbed motion of the hose in the vertical plane and the hose tension are obtained. The resulting dynamic linear equations have variable coefficients that depend on both the initial steady-state static equilibrium position and the static tension of the hose. Owing to the control surface motion, unsteady aerodynamic forces are generated. These forces depend on the drogue local vertical velocity and on the hose slope at the drogue position, and are approached by means of Theodorsen’s theory. The natural frequencies and normal modes of the complete system are calculated. In addition, the responses to the tanker oscillation/pulse excitation to gust and turbulence are obtained. Finally, the influence of the different parameters on the dynamic response of the hose-drogue–control surface system is presented.