The effect of blade surface grooves on performance of axial fan

This paper explores the effect of blade surface grooves on the axial fan of central air-conditioner outdoor units in detail through experiments and three-dimensional unsteady simulations. The experimental results reveal that the newly designed fan with surface grooves can reduce noise by 1.2 dB(A) without sacrifice of aerodynamic performance. The simulation results demonstrate that the effect of the surface grooves is localized and does not alter the overall load distribution of the axial fan. However, it does affect the tip leakage vortex. The tip leakage vortex is a large-scale vortex that interacts with small-scale vortices shedding from the blade surface grooves, resulting in the weakening of the tip leakage vortex and the secondary tip leakage vortex. Ultimately, this leads to a reduction in the noise of the air-conditioner outdoor unit. This new strategy based on blade surface geometric design provides a novel idea for tip leakage flow control and has significant engineering application value.