허브 캡 형상에 따른 축류송풍기 성능특성

초록

Performance characteristics of an axial flow fan having distorted inlet flow were investigated by numerical simulation and experiments. The distorted inlet flow was obtained by changing the shape of hub-cap installed upstream of the hub of the axial flow fan. Two types of the hub-cap shape were introduced to understand the effect of inlet flow distortion on the fan performance. Three-dimensional flow measurements upstream and downstream of the fan rotor were performed by a five-hole Pitot tube, and numerical analysis of the blade passage is performed by three-dimensional Reynolds-averaged Navier-Stokes equations. The distorted inlet flow invokes the increase of inlet flow angle due to the decrease of axial velocity, thus resulting in flow separation on the blade suction surface. The flow separation deteriorates fan performance near the hub. Detailed flow characteristics in the blade passage with relation to the different shape of a hub-cap were also analyzed.