遷音速における動的試験

抄録

Descriptions about two dynamic test techniques in a transonic wind tunnel are given together with the obtained results. The first is measurements of dynamic stability derivatives of cones and a delta wing employing the free oscillation method. By use of a refined model driving mechanism and a newly designed damping meter accurate values of dynamic stability derivatives were obtained with increased efficiency. The second is the measurement of surface pressure fluctuations of a two dimensional oscillating airfoil. Very small pressure transducers are installed in the model, which is oscillated in pitch by an electromagnetic shaker, and the corresponding pressure signals are analysed harmonically. From the fundamental component dynamically stable and unstable regions over the model were determined and the integrated stability derivatives were obtained. At the same time relation between the higher harmonics and the mechanism of an unsteady transonic flow was also studied.