Static and Dynamic Wind Tunnel Testing of Air Vehicles In Close Proximity

Bihrle Applied Research Inc. has developed unique capabilities for investigating the aerodynamic effects on aircraft in close formation. Wind-tunnel experiments were conducted at the Langley Full-Scale Tunnel using special hardware and computer equipment developed specifically for formation testing. It was demonstrated that static and dynamic force and moment data, as well as surface pressure data and wake survey data, can be acquired and utilized to analyze and model vehicle in close formation flight. The data acquired is well suited for use in flight vehicle simulation for development of control laws for automated formation flight and automated refueling. Unique to this wind tunnel testing was the simultaneously collection of force and moment data from two separate models positioned differently during each run. Also unique was the dynamic testing conducted to determine the control surface deflections required to trim the trail vehicle in various formation positions.