Small distributed sewage treatment systems have attracted a great deal of interest in recent years due to the environmental issues in China.Micro turbo blowers show great potential in small distributed sewage treatment systems.However,one technically challenging application for such micro turbo blowers is the high rotational speed.To fulfill the requirement of small size distributed sewage treatment systems,the rotational speed should be in the order of 100 krpm to reach an appropriate pressure ratio with a small flow.For operating at such a high rotational speed in the system,to assure longer service life and little potential risk of water contaminants,high speed bearings are needed and there are also other requirements regarding non-contacting and oil-free character.Foil air bearings(FABs),one of the major kinds of non-contacting and oil-free bearings,not only has capability of operating at very high speed,but also owns good stability and the absence of risky oil pollution.Therefore,foil air bearings have been applied in high speed blowers to improve their efficiency,which leads to develop a new version of blowers,air bearing blowers.In this work,a high speed(~100 krpm)micro air bearing blowers,supported by foil air bearings and driven by a high speed permanent magnet synchronous motor,was designed and analyzed numerically.The detailed designs of the micro turbo blower were presented including the blower configuration,the impeller and the foil air bearings.Moreover,the dynamic characteristic of the blower rotor-bearing system have also been analyzed.