Beamforming studies on basic models of low-speed axial fan blade sections

Authors

Esztella Balla - Department of Fluid Mechanics, Faculty of Mechanical Engineering, Budapest University of Technology and Economics
Janos Vad - Department of Fluid Mechanics, Faculty of Mechanical Engineering, Budapest University of Technology and Economics

Abstract

The paper reports on establishing a beamforming dataset, relying on the phased array microphone (PAM) technique, on the broadband noise of rectilinear basic models of low-speed axial fan blade sections. A cambered plate profile is in the focus of the studies, in comparison with a flat plate and a traditional airfoil profile. At low Reynolds numbers, cambered plate blade sections have a potential to perform aerodynamically better than profiled airfoil sections. Thus, the established dataset aims at contributing to the design background of aerodynamically efficient, low-noise, low-Reynolds-number fans. The wind tunnel-PAM configuration enables the acoustic investigation over the plane being normal to the spanwise direction at midspan. An illustrative study on representative cases selected out of the dataset demonstrates the capabilities and limitations of the presently available experimental and evaluation method. Spatially simultaneously resolved information is presented on the signatures of systematically investigated classes of blade section noise.