Effect of Several Kinds of Pile-Fabrics on Reducing Aerodynamic Noise (Phase 1)

Abstract

Pile-fabrics are known to be usefull for reducing aerodynamic noise. But it is not clear which parameter of pile-fabrics have large correlation with the amount of noise reduction. Is this paper, simple experiments were performed, in order to examine which kinds of pile-fabrics are effective for reducing aerodynamic sound radiation. A pipe with and without pile-fabrics was set at the nozzle exit of a quiet wind tunnel and measured radiated sound. Several kinds of parameters of pile-fabrics were measured and the correlation between every parameter and the noise reduction was examined. As the result, it became clear that some length of fibers is necessary for reducing aerodynamic noise and twined pile-fabrics are effective.