Effects of Restricted Inlet Flow on P-Q Characteristics of Small Axial Fans in Thin Enclosure

Abstract

This paper describes P – Q characteristics of small axial fans mounted in high-density packaging electronic equipment. The correct supply flow rate of the fans in high-density packaging electronic equipment cannot be predicted due to a deterioration of the fan performance. In this study, the P-Q characteristics of the small axial fan in the narrow enclosure, which the inlet flow of the fan was curved, by the enclosure was measured. Furthermore, the relationship between the fan performance and the flow pattern was evaluated through flow visualization. It is found that the supply rate of the fan is deteriorated when the distance between the fan inlet and the enclosure wall becomes narrower and the inlet flow pattern becomes complex by the generation of the pre-rotation flow.