Aerodynamic Optimization and Noise Reduction of a Two-Stage Series Compact Fan

This paper focused on the aerodynamic optimization and noise reduction of a two-stage series compact fan. The space constraints of compact fans limit the design space, which poses several challenges to aerodynamic and noise performance. The aerodynamic performance and noise characteristics of a baseline series axial fan show that the interaction between the first-stage and second-stage fans is weakened because of the effect of the honeycomb panel. A dual-objective optimization of the rotor blade with the power consumption and static pressure efficiency as the design objectives was carried out on a single-stage axial fan based on a radial basis function (RBF)-enhanced differential evolutionary (RADE) algorithm. The result showed that the dual-objective optimization achieved good results in the aerodynamic design of the two-stage series fan. Compared with the baseline configuration, the static pressure efficiency of the optimized axial-flow fan increased by 6%. The first blade-passing frequency (BPF) noise was reduced by 7 dB. An expansion shroud was designed based on the optimized design of the axial-flow fan. The expansion shroud configuration further increased the static pressure efficiency by 10%.