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.

本文针对无蜗壳离心风机，提出了一种降低风机气动噪声的方法。通过流体和声学模拟以及实验研究，对风扇进行了检查。该创新方法包括在离心风机叶轮前盘处采用防涡环结构，并分析了该结构对风机运行效率和噪声特性的影响。在此基础上，对结构参数进行优化，控制叶轮涡度，从而提高HW355离心风机的整体性能和降噪效果。此外，使用 Lighthill 类比方法进行噪声模拟，它将湍流和噪声的耦合转换为静态介质中等效声源的声学分析。通过对频域结果、噪声指向性特征、子午面上声压级分布的分析，并进行噪声实验，对无蜗壳离心风机的声学特性进行了综合分析。研究验证了创新防涡环结构对无蜗壳离心风机气动噪声的优化效果。对无蜗壳离心风机的声学特性进行了综合分析。研究验证了创新防涡环结构对无蜗壳离心风机气动噪声的优化效果。对无蜗壳离心风机的声学特性进行了综合分析。研究验证了创新防涡环结构对无蜗壳离心风机气动噪声的优化效果。