13th European Conference on Turbomachinery Fluid dynamics & Thermodynamics
This paper describes the investigation of a contra-rotating axial fan. It has a shroud diameter of 300 mm and a rotational speed of 1920 min-1 and 1200 min-1 for the first and the second impeller, respectively. It is designed for an air-flow rate of 0.486 m3s-1 and for total pressure difference of 180 Pa (120 Pa at the first and 60 Pa at the second impeller). The main focus lies on the correlation of flow structure and the noise emission. Therefore, the flow structure is investigated by means of Particle Image Velocimetry (PIV) and the noise emission with an Acoustical Camera. PIV is established at a non-rotating model of the blades. For localizing the noise sources, a rotational beamforming algorithm is applied allowing the determination of noise sources on a rotating fan.