1、3950 英文单词，英文单词，2.1 万英文字符万英文字符，中文中文 6000 字字 文献出处：文献出处：Paramasivam K, Rajoo S, Romagnoli A. Suppression of tonal noise in a centrifugal fan using guide vanesJ. Journal of Sound and Vibration, 2015, 357: 95-106. Suppression of tonal noise in a centrifugal fan using guide vanes Kishokanna Paramasivam, S
2、rithar Rajoo, Alessandro Romagnoli Abstract This paper presents the work aiming for tonal noise reduction in a centrifugal fan. In previous studies, it is well documented that tonal noise is the dominant noise source generated in centrifugal fans. Tonal noise is generated due to the aerodynamic inte
3、raction between the rotating impeller and stationary diffuser vanes. The generation of tonal noise is related to the pressure fluctuation at the leading edge of the stationary vane. The tonal noise is periodic in time which occurs at the blade passing frequency (BPF) and its harmonics. Much of previ
4、ous studies, have shown that the stationary vane causes the tonal noise and generation of non-rotational turbulent noise. However, omitting sta- tionary vanes will lead to the increase of non-rotational turbulent noise resulted from the high velocity of the flow leaving the impeller. Hence in order
5、to reduce the tonal noise and the non-rotational noise, guide vanes were designed as part of this study to replace the diffuser vanes, which were originally used in the chosen centrifugal fan. The leading edge of the guide vane is tapered. This modification reduces the strength of pressure fluctuati
6、on resulting from the interaction between the impeller outflow and stationary vane. The sound pressure level at blade passing frequency (BPF) is reduced by 6.8 dB, the 2nd BPF is reduced by 4.1 dB and the 3rd BPF reduced by about 17.5 dB. The overall reduction was 0.9 dB. The centrifugal fan with tapered guide vanes radiates lower tonal noise compared to the existing diffuser vanes. These reductions are achieved without compromising the performance of the centrifugal fan. The behavior of the
