Wind-tunnel test techniques for unmanned aerial vehicle separation investigations

Abstract

Wind-tunnel tests of an unmanned aerial vehicle (UAV) separating from two fighter aircraft have been conducted. UAVs present different concerns in separation testing than do conventional stores due to the presence of large lifting surfaces, physical size, and control surface effects. The planning and results of these recent investigations give several new results with respect to the separation testing of complex configurations. Separation trajectory simulations using experimental data have been used to demonstrate the unique requirements of UAV separation testing. The simulation demonstrates that simplifications in the aerodynamic grid proximity testing matrix can be made without sacrificing simulation accuracy. Results indicate that simplification in ejector modeling used with simple stores should not be applied to UAVs. The simulations also indicated that it is important to properly model the aircraft control surface effects on the UAV. NomenclatureMy.-freestream Mach number X, 7, Z = store longitudinal, lateral, and vertical displacements in the aircraft axis system (aligned with the aircraft longitudinal axis, origin is at the store center of gravity); positive forward, right and down, ft X P , y/>, Z P = store longitudinal, lateral, and vertical displacements in the pylon axis system (aligned with the store longitudinal axis, origin is at the store center of gravity); positive forward, right and down, ft a = aircraft angle of attack, deg 0 = store pitch angle, positive nose up as seen by the pilot, deg 0 = store roll angle, positive clockwise rotation looking upstream, deĝ = store yaw angle, positive nose right as seen by the pilot, deg

Design and Analysis of a Light Cargo UAV Prototype

“…However, nowadays there is increased interest for UAV applications in the public sector for a vast area of applications [11][12][13] ranging from rescue operations to surveillance and monitoring. The first UAV designs that appeared in the early nineties were based on the general design principles for full aircraft and findings of experimental inverstigations 14 . Often the main limitation of commercial general purpose UAV's is low cost.…”

“…The tremendous increase of computing power in the last two decades and developments of general purpose reliable CFD software packages made possible the use of full configuration CFD techniques for the design, evaluation, and optimization of modern UAV. Several recent works [14][15][16] used CFD analysis for new UAV designs even for cases where innovative unconventional designs were employed. The competition Air Cargo Challenge was initiated by APAE (Portuguese Association of Aeronautics & Space) in 2003, inspired by the North American Design Build & Fly (DBF) aircraft university competitions.…”