Effect of clearance jet on aerodynamic performance of centrifugal fan

Abstract

The change of the depth of the inlet collector inserted into the impeller will change the gap shape between the collector and the impeller, and then affect the performance of the ventilator. Taking the small centrifugal ventilator as the object, the influence of the depth of the impeller inserted into the collector on the aerodynamic performance of the ventilator is studied in this paper. Firstly, the depth of the collector inserted into the front disk of the impeller is adjusted to 2 mm, 3 mm and 4 mm respectively to change the geometry of the clearance. Then, based on the computational fluid dynamics analysis method, the influence of the insertion depth of the above three different concentrators on the aerodynamic performance of the ventilator is analyzed. The analysis results show that the gap leakage is positively correlated with the depth of the impeller inserted into the collector, and the aerodynamic performance of the ventilator can be significantly improved by reducing the insertion depth of the collector under the conditions of design flow rate and large flow rate, but under the condition of small flow, the decrease of insertion depth weakens the effect of gap jet on the flow field in impeller, resulting in the decrease of fan efficiency and static pressure.