Caractérisation des sources de bruit aérodynamique sur un ventilateur centrifuge à flux axial

This paper is an experimental investigation of the aerodynamic noise sources in a centrifugal fan with outlet guide vanes and axial outflow. Special piezoplastic sensors are used for the measurement of the pressure fluctuations on the blades. Classical signal processing procedures provide the blade loadings harmonics. When the fan operates at a relatively high flow rate and low efficiency, it is verified that higher loading harmonics are responsible for the noise emitted at the blade passing frequency. Conversely, at the maximum efficiency, only the first loading harmonic is noticeable, and the tone noise is suppressed