Efficient and Noise Reduced Design of Axial Fans Considering Psychoacoustic Evaluation Criteria

Abstract

Axial fans are the largest group of blowers and thus have a significant impact on their environment: Their demand for electrical power and the generation of a significant noise emission, have a negative impact on the environment.In this work the improvement of efficiency and reduction of noise emission are subject of the investigations. Several types of low-pressure axial fans are subject of this investigation. Measurements of pressure rise, efficiency and acoustic behavior will be presented for different blade geometries. The modifications of forward- and backward-skewed blades are compared to a unskewed blade geometry. The forward-skewed configurations show an improvement on the hydraulic properties, the efficiency and reduce the noise emission whilst the backward-skewed configurations improve the acoustic behavior at low flow rates with flow detachment occurring. Besides an acoustic quantification of the noise emission using the sound power level, psychoacoustic methods like loudness and sharpness were used.