Study of the 3D Flows in the Forward-Curved Blades Centrifugal Fans

The study presented in this paper is part of the research work on forward-curved blades centrifugal fans carried out the last years by the « Laboratoire d’Energe´tique et de Me´canique des Fluides Interne » (Lemfi – Site Paris). The objective of this study is to better understand the internal flow in this type of machine in order to be able to correlate the aeraulic and acoustic behavior with the geometrical characteristics of the machine. Two impellers with different profiles were manufactured and tested. The aeraulic and acoustic tests were carried out on a test bench standardized ISO 5801. The 3D CFD of the flow was carried out with a commercial code based on the resolution of the Navier-Stokes equations in finite volumes. The analysis of these results confirms that a more organized flow field leads to a better acoustic performance.