鳥翼端模倣翼によるBoxファンの低騒音化に関する研究

抄録

In this study, a numerical analysis using the Lattice Boltzmann Method and noise measurements were performed on a test fan equipped with a Multi-Slotted blade that mimics a Bird's Wing Tip geometry. The tested fan is a small axial type for server cooling, equipped with 5 rotor blades and 7 rear-mounted stated blades and covered with a casing. The LBM analysis confirmed the complex flow field inside the casing and clearly visualized the blade tip leakage vortex. It was also confirmed that the non-axisymmetric bell-mouth shape have a significant effect on the flow field near the blade tips and the noise source term. Downstream of the rotor blade, a Multi-Slotted blade was found to attenuate the blade tip leakage vortex compared to the base model through the static pressure distribution results. According to noise measurements, first order BPF noise in the Multi-Slotted blade was reduced by approximately 5dB compared to the base model. The overall value in the one Multi-Slotted blade was reduced by approximately 0.9dB compared to the base model.