Rotor-Stator Distance Effect onto Axial Fan Performance Improvement

Abstract

Past researches have studied the stator blade guide vane angle implementation respective to the rotor blade angle. And outlet guide vane is recommended to encounter the air swirl problem occurs in the axial flow fan compared to inlet guide vane. This paper presents an investigation on the distance between rotor-stator for an outlet guide vane with fixed stator angle. Two specimens were studied: 30° rotor and 34° stator, and 40° rotor and 44° stator. The stator angle was obtained from previous study, which is the optimized angle for the presented stator blade profile. The distance of 50mm and 500mm between rotor and stator is investigated in this study. This would be the constraint length of motor spacing between rotor and stator. This investigation is to explore the possibility of positioning the guide vane after the motor as a separate fixture to reduce manufacturing and assembly cost of guide vane. To investigate the flow structure and to analyze qualitatively commercial CFD package, FLUENT is exploited. The computational model was validated against experimental data. The experimental analysis is done in reference to AMCA 210-07 standard test procedure and the data presented for rotor without stator guide vane model. The performance curve of the axial fan was plotted to compare the effect of the guide vane distance between rotor and stator. The efficiency curve also obtained from measured power input to motor. The results shows the 50mm-distanced stator perform better than the 500mm-distanced stator. This is because the high swirling of flow from the rotor is well-corrected by the 50mm stator compared to the 500mm stator.