Accession Number : ADP003782

Title :   A Self-Contained Captive Trajectory System for a Blowdown Wind Tunnel,


Personal Author(s) : Christopherson,C. D. ; Kamis,D. N. ; Nelson,D. M. ; Week,R. D.

Report Date : FEB 1984

Pagination or Media Count : 9

Abstract : The trajectory of a store which is released from an aircraft can be determined by model tests using a six-component sting balance to measure the aerodynamic forces and moments on the shell. This paper describes a completely self-contained Captive Trajectory System which has been configured to provide maximum efficiency in the use of wind tunnel test time. Three primary factors which contribute to achieving this goal are: the self-contained nature of the system; the use of high performance electrohydraulic servo positioning systems for all motions; and the use of a modern high speed minicomputer and appropriately matched amplifier/multiplexer I/O equipment to acquire information, perform the mathematical manipulations required, and provide appropriate inputs to the servo systems. This system contains four subsystems: the structural/mechanical system; the electrohydraulic positioning systems; the minicomputer based analyzer/programmer system; and the software system. An overview is given the wind tunnel circuit, a 4 ft x 4 ft (1.2 m x 1.2 m) trisonic blowdown which has been configured to provide high flow quality by use of a perforated sleeve valve flow control, perforated flow diffusers, acoustic baffles, a honeycomb, and screens.

Descriptors :   *Wind tunnel models, External stores, Trajectories, Computer applications, Equations of motion, Input output devices, Minicomputers, Aerodynamic forces, Moments, Captive flight, Positioning devices(Machinery), Hydraulic servomechanisms, Blowdown, Wind tunnels, Self contained, Degrees of freedom, Sting mounts

Distribution Statement : APPROVED FOR PUBLIC RELEASE