Accession Number : ADP005042

Title :   Identification of Aircraft Characteristics Including Gust Induced Dynamic Effects,

Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V BRUNSWICK (GERMANY F R)

Personal Author(s) : Rohlf,D.

Report Date : NOV 1985

Pagination or Media Count : 8

Abstract : To investigate unsteady aerodynamic effects at low Mach numbers, dynamic tests using controllable models of a light transport aircraft were performed in the Dynamic Simulation Facility in Wind-Tunnels at DFVLR-Braunschweig (Germany) and in the Free Flight Catapult Facility of IMF-Lille (France). These model test techniques have the advantage of laboratory conditions with the possibility of generating reproducible gusts. The achieved flight test data were analyzed in detail applying methods of System Identification. This included the determination of the discrete gust disturbance from onboard measured signals. This paper presents the special approach using the measured angle of attack and additional calculated dynamic terms which become essential in the presence of fast flow changes due to short-wave gusts or high-frequency control deflections. Measured time histories of model flight tests with excitation by control inputs and gusts are presented and compared with identification results obtained from multi-run evaluation.

Descriptors :   *GUST LOADS, TRANSPORT AIRCRAFT, AERODYNAMIC CHARACTERISTICS, PITCH(MOTION), DYNAMIC RESPONSE, EXPERIMENTAL DATA, ANGLE OF ATTACK, MEASUREMENT, DEFLECTION, HIGH FREQUENCY, WIND TUNNEL MODELS, AIRCRAFT MODELS, MATHEMATICAL MODELS, WEST GERMANY

Distribution Statement : APPROVED FOR PUBLIC RELEASE