羽根枚数が小型シロッコファンの舌部周りとケーシング内部の流れ場に与える影響

抄録

Recently, fans have been used for cooling electric devices. Sirocco fan has been used in narrow place especially because it has characteristics of high pressure and high flow rate. But noise of sirocco fan becomes loud, so it's very important to reduce noise of sirocco fan. So far, there were a lot of attempts to reduce noise of sirocco fan by performing experiments and numerical analysis. However, there is little knowledge for reducing noise regarding sirocco fan with small number of blades. There is advantage that can reduce production cost of sirocco fan if it has small number of blades. Purpose of this study is to clarify flow fields around tongue and in scroll casing of small sirocco fan with small number of blades (Z=22, 11) by using LES compared with general number of blades (Z=40). As a result, it was clarified that pressure fluctuation on tongue in case of Z=22 was high compared with Z=40 and Z=11 at maximum efficiency point, and pressure fluctuations on scroll casing surface in case of Z=22 and Z=11 were high compared with Z=40 at maximum efficiency point.