Summary: | 碩士 === 國立臺灣科技大學 === 機械工程技術研究所 === 86 === An investigation of the performance and noise for a P. C. cooling fan is executed. At first, a basic geometry of an axial fan is generated from the theoretical analysis; then, the experiments for performance and noise characteristics are carried out in the AMCA standard test chamber and semi-anechoic chamber. Thereafter, a parametric study on the geometry of fan is performed to enhance the understanding of the corresponding influences caused by those variations. The parameters considered here include the tip clearance between casing and impeller, improverments on the housing, blade leading edge, blade surface, and blade section.Notable, to ensure a reliable experiment, all the experimental procedures are set up according to the AMCA 210-85, ISO-3745, and ISO-9614-1 standards. In summary, the experimental results show that the decreasing of tip clearance and drilling hole on the housing are the dominant methods to enhance the efficency by 26.78% and 17.95%, respectively. However, no significant improvement on the noise level is observed. Besides, the noise level can be reduced by 2 dBA for geometric variations of the blade leading edge; in addition, the broad-band frequency is diminished significantly for the addition of round bar on the blade leading edge. Furthermore, an extensive and detailed discussion for the effects on other parameters is provided.
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