On the measurement of motion induced forces on models in turbulent shear flow

Abstract An experimental system for the measurement of motion induced forces on a base pivot model has been developed which makes use of a rigid geometric model as commonly used in the motionless base-balance technique. The system not only affords in practical cases a check for potential negative aerodynamic damping, but also promises to provide a significant tool for the fundamental research into the phenomenon of motion induced forces. Typical results are shown, including an important reliability test. Also included is an illustration of the variation of the motion induced force with oscillation amplitude for a prism of square cross section with a height to breadth (aspect) ratio of 13.33.