Acoustic Characteristics of Two Circular Cylinders Forming a Cross in Uniform Flow (Effect on Noise Reduction and Flow Around Both Cylinders) : Solid-Mechanics, Strength of Materials

Abstract

In the turbulent wake behind and upstream cylinder in a uniform flow, the downstream cylinder was set in the form of an intersection with the upstream cylinder. It was found that the acoustic radiation from the two circular cylinders forming an intersection was far smaller than that of a single cylinder. The variation of the acoustic radiation was measured by varying the intersectional angle of the two cylinders, the point of mutual contact and the angle between the downstream cylinder and the uniform flow. Moreover, measurements were made on (1) the mean and fluctuating surface pressure distributions on both cylinders, and (2) the mean velocity profiles and fluctuating velocity distributions in the turbulent wake behind the upstream cylinder. The flow patterns were verified by oil-film and smoke-wire flow visualization. Then, the relationship between the flow and the noise generation was studied.