小型多翼送風機の性能と騒音に関する実験的研究: （スクロールケーシング諸元の影響）

摘要

多翼送風機は前向き羽根を有する遠心型送風機で， 低圧，大流量を特徴とする．また，吐出し口を矩形に 製作できることから空調機器などに多く組み込まれて いる．近年は大型コンピュータなどの情報機器冷却用 として広く用いられており，冷却能力の要求の高まり とともに，フアンの性能向上，騒音低減が求められて いる．%Small fans are especially used in information device for its cooling. Since packaging density has been increasing, requirements of not only performance improvement but also noise reduction arise strongly. An experimental research on small multi-blade fan was carried out in order to improve performance and reduce noise. In this report, effects of scroll angle, tongue clearance and inlet diameter on small multi-blade fan with impeller diameter of 100 mm were investigated. The optimal index efficiency and noise were found by making a scroll starting point radius and a scrool termination radius into a design index, instead of the scrool design by a conventional clearance and a scroll angle. In order to reduce noise, we found that we should set the radius of scroll beginning into about 0.65 times of the outlet diameter of the impeller. And for improving efficiency, we should set the radius of scroll end into about 0.9 times of the outlet diameter of the impeller.