In order to clarify the effect of tip clearance (TC) size on fan performance and the flow field at rotor outlet in asmall semi-open axial fan, the experimental investigation was carried out. The tip diameter of test f...In order to clarify the effect of tip clearance (TC) size on fan performance and the flow field at rotor outlet in asmall semi-open axial fan, the experimental investigation was carried out. The tip diameter of test fan rotor was180mm and test TC sizes were lmm (TC=1mm) and 4mm (TC=4mm). Fan characteristics tests were carried outfor two cases of TC size and three-dimensional velocity fields at rotor outlet were measured using a single slanthot-wire probe at four flow-rate conditions. As a result, it was found that the pressure - flow-rate characteristicscurves for two cases showed almost the same tendency. However, the ensemble averaged velocity profiles alongradial measurement stations of TC=4mm largely changed compared with that of TC=lmm in cases of smallflow-rate condition. From the phase-locked averaging results, it was also found that the vortex existed in the rotoroutlet flow field of high flow-rate condition for each TC case. Compared with the vortices for TC=1mm andTC=4mm, the vortex for TC=4mm was stronger than that for TC=1mm.展开更多
文摘In order to clarify the effect of tip clearance (TC) size on fan performance and the flow field at rotor outlet in asmall semi-open axial fan, the experimental investigation was carried out. The tip diameter of test fan rotor was180mm and test TC sizes were lmm (TC=1mm) and 4mm (TC=4mm). Fan characteristics tests were carried outfor two cases of TC size and three-dimensional velocity fields at rotor outlet were measured using a single slanthot-wire probe at four flow-rate conditions. As a result, it was found that the pressure - flow-rate characteristicscurves for two cases showed almost the same tendency. However, the ensemble averaged velocity profiles alongradial measurement stations of TC=4mm largely changed compared with that of TC=lmm in cases of smallflow-rate condition. From the phase-locked averaging results, it was also found that the vortex existed in the rotoroutlet flow field of high flow-rate condition for each TC case. Compared with the vortices for TC=1mm andTC=4mm, the vortex for TC=4mm was stronger than that for TC=1mm.
