Noise Optimization and Experimental Verification of Voluteless Centrifugal Fan

This paper focuses on the voluteless centrifugal fan and proposes a method to reduce the aerodynamic noise of the fan. Through fluid and acoustic simulations, as well as experimental investigations, the fan is examined. The innovative approach involves the implementation of an anti-vortex ring structure at the impeller front disk of the centrifugal fan, and the influence of this structure on the fan's operational efficiency and noise characteristics is analyzed. Based on this analysis, the structural parameters are optimized to control the vorticity of the impeller, resulting in improved overall performance and noise reduction of the HW355 centrifugal fan. Furthermore, noise simulations are conducted using the Lighthill analogy method, which transforms the coupling of turbulent flow and noise into an acoustic analysis of equivalent sound sources in a quiescent medium. By analyzing the results in the frequency domain, noise directivity characteristics, sound pressure level distribution on the meridional plane, and conducting noise experiments, a comprehensive analysis of the acoustic characteristics of the voluteless centrifugal fan is conducted. The study verifies the optimization effects of the innovative anti-vortex ring structure on the aerodynamic noise of the voluteless centrifugal fan.