Aeolian Tones Associated with Resonant Vibration

Experiments were conducted on taut wires stretched normally across an open jet test section of a low turbulence wind tunnel at various subsonic wind velocities. Measurements were taken of radiated sound-pressure level, lateral spatial correlation of wake velocity fluctuation, end-support acceleration, wire damping, and oscillatory lift on the wire for various ratios of vortex shedding frequency to wire resonant frequency for the first four wire-resonant frequencies. The radiated sound was essentially dipole at the Strouhal frequency of vortex shedding. Its intensity increased as U20 as the Strouhal frequency approached a wire resonant frequency from below. This is markedly in excess of the U6 dependence predicted by Phillips [J. Fluid Mech. 1, Pt. 6 (1956)] for rigid cylinders. The difference results from the influence of resonant vibration upon the root-mean-square sectional lift coefficient and the correlation length of vortex shedding. [Work carried out under General Hydromechanics Research Program administered by the David Taylor Model Basin, U. S. Navy.]