円弧翼から発生する広帯域騒音のスペクトル分布と後流特性の関係

概要

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In this study, an analytical prediction theory of the spectra of the broadband noise generated from an arc blade is proposed. The discrete circulations of the wake vortices divided into n pieces were given by the peripheral velocity and a diameter of the vortex core in the solid vortex. The spectra of the broadband noise were represented as a series of the local lift fluctuation produced by the circulations to the solid surface. The wake characteristics and the spectra of the aerodynamic noise were measured by the wind tunnel experiment. The influence of the angle of attack on the characteristics of the noise spectra were quantitatively analyzed from zero degree to forty degree. The difference between the predicted sound pressure level by the wake characteristics and the measured one was less than 2.3 dB. From results of the analysis of the predicted spectra of the broadband noise, it was quantitatively estimated that the ratio of the broadband noise in the over all noise became large when the angle of attack became large.
長崎大学の論文