Development and Performance Evaluation of a Micro Air Blower

Micro air blowers are used in a wide range of applications such as cooling battery packs for electric vehicles, portable medical devices and computers as well as active boundary layer control. Recently, boundary layer suction is proposed to be applied to vertical axis wind turbine blades in order to improve its performance either through direct suction from blade surface before the separation point, or through surface cavity. In VAWT boundary layer control through suction, blower pressure ratio varies as the blade travels along its rotational path. Preliminary investigations for a VAWT model composed of 3 blades of 1 m length and 200 mm chord show that the required micro blower flow rate ranging from 10 to 36 m3/h at a differential pressure range from 0.5 to 1.3 kPa. Since such micro air blower operating range have not been reported previously, it was decided to design and test a prototype in order to examine the applicability of common air blower design techniques in this small scale. The present paper aims at reporting the preliminary design, simulation and experimental testing results of a micro air blower in the specified working range. The blower design is made using Euler equations. A physical model is manufactured using 3D printing and tested at 14.5 k rpm. The driver electric motor is a high speed motor suitable for remote speed adjustment. Furthermore, the blower performance maps are obtained using steady-state 3D viscous numerical simulations. The paper includes both experimental and CFD results. Recommendations to improve the performance of this micro air blower are also included.