ROLL OSCILLATORY TEST IN A LOW SPEED WIND TUNNEL

The paper deals with the measurement of the dynamic stability derivatives of a generic combat aircraft model undergoing forced oscillation motion in roll. The experiments are performed in the 8’ x 10’ low -speed, closed circuit Ankara Wind Tunnel (AWT). The model used for measurements is the so called “Standard Dynamic Model”, which is used for wind -tunnel tests in various NATO countries. The model was designed and manufactured within the scope of a NATO AGARD Working Group (WG16) project. The aerodynamic loads acting on the model are measured by means of a five -component internal strain gauge balance. The elaboration of the signal output of the balance is analyzed, according to the small -amplit ude direct forced oscillation technique. This technique is a reliable method used to obtain basic dynamic stability derivatives without solving the equations of motion. The paper presents the test rig used to perform the oscillatory tests in the roll plane , the motion control and the data acquisition units that are interfaced to the test rig to measure the aerodynamic loads. A brief review of the forced oscillation technique is also given and the results of the measurements are briefly discussed .