Noise emission from various shape rods at low-moderate Reynolds number

Aeroacoustic source localization is an important experimental tool and the first step to know the mechanism of noise generation. The flow around the various shape of rods is one of the major aeroacoustic noise source mechanism. Such rods represent simple models for technical applications like part of the landing gear of planes, train pantographs, antennas, vehicles part, ventilation system or bridge. The purpose of this paper is to clarify the influence of the rod shape in the noise generation mechanism in a low-moderate Reynolds number. In this work, the situation when various shape rods are in the area of laminar-turbulent flow was analyzed. The measurements were carried out for single circular, square, c-shape rods to study the noise effect depended on the Reynolds number. The measurements were performed on the specially constructed test stand with the outlet to the anechoic room. The 1/3 SPL differential spectrum as 2-D noise maps were obtained for studied rods. The acoustic differences between circular, square and U-beam rods were observed.