A numerical investigation on the performance improvement of axial-flow automotive cooling fan with beads

This paper presents a CFD analysis of three types of axial-flow magnesium-based automotive cooling fans. The numerical modeling was conducted for geometrically modified fan designs: one with no-beads, the second one with beads at the suction-side of the fan namely reverse-beads fan, and the third one with beads installed at the pressure-side of the fan namely forward-beads fan. The effect of geometric modifications of the fan blades on the volumetric flow rate, fan efficiency, and energy efficiency was investigated using Reynolds-averaged Navier-Stokes (RANS) equations following the multiple reference frame methodology. The fan with no-beads was fabricated using 3D printing technology and tested to measure the flow velocity. Subsequently, the fans with beads along with the no-beads fan designs were numerically analyzed. The volumetric flow rate, fan efficiency, and energy efficiency were quantified as a function of fan rotating speed. The results show that the reverse-beads fan produced a relatively more volumetric flow rate and energy-efficient compared to the forward-beads fan. Moreover, to further improve the performance of the reverse-beads fan, the location and size of the bead structure were varied along the radial direction of the fan blade. The optimized reverse-beads fan significantly improves the fan performance.