Experimental investigation of the noise reduction of a plug fan with leading-edge serrations
* Presenting author
In previous years, leading-edge serrations have been successfully used as a noise-reduction technique applied to airfoils. More recently, this technique has been also used and validated on axial fans. In this study, sinusoidal leading-edge serrations have been integrated on a plug fan (centrifugal fan without volute). The outcome of RANS simulations of the non-serrated baseline impeller has been used to define an assumed optimum serration geometry in terms of noise reduction. This optimum geometry has been used as a reference to manufacture three impeller prototypes of various geometries, defined by their amplitude (2h) and wavelength (λ).This paper will present the results of the test of the prototypes in a reverberant room, where noise and air performance measurements are done simultaneously. For each impeller, five fan operating points will be presented, and for each one of the points the sound power level is measured at both the inlet and the outlet of the fan. This allows us to assess the effectiveness of serrations at different operating points, while checking the impact on the fan efficiency. The results will also be compared with the non-serrated baseline fan.