Acoustic Radiation from a Stationary Cylinder in a Fluid Stream (Aeolian Tones).

The equation for the radiated sound associated with body forces in a fluid is applied to the flow past a circular cylinder. The sound field is found to be related to the oscillating lift and drag forces which act on the cylinder. Quantitative predictions are made of the directionality and intensity of the field. Some experiments were conducted in a subsonic wind tunnel, in order to test the theory. The microphone was located both inside and outside the tunnel. Over-all sound pressure levels and sound spectra were measured with various cylinders mounted in the test section. There is qualitative agreement between the theory and the experimental results. [ABSTRACT FROM AUTHOR]