基于内部流场分析的小型轴流风扇结构优化

采用孤立叶型设计法、CFD技术、遗传算法等理论，运用自编软件对某一轴流风扇轮毂比参数进行结构优化设计，优化目标为风扇流量。对比分析优化前后风扇内部流场，如风扇的静特性、叶片表面静压分布、子午面涡量分布等信息。由此验证优化方法的可行性．，并总结轮毂比参数对此风扇性能的影响。结果表明：优化后风扇叶片和轮毂表面减小了因涡流带来的能量损失，但叶顶间隙处的涡流增大，能量损失略有增大；在不同流量下，优化后风扇静压有不同程度的提高；优化后风扇的出口速度均比优化前大幅提高；风扇在额定工况下性能、静特性及内部流场都得到了很好的改善。

Small Axial Fan Structure Optimization Research Based on the Analysis of the Internal Flow Field

In the paper, the authors apply theories of isolated blade design method, CFD technology,genetic algorithm, and use self-made software to optimize the hub ratio of axial flow fan. The optimization objective is fan flow. Then the authors comparatively analyze the fan internal flow field, including static characteristic, blade surface static pressure distribution and meridian plane vortex quantity distribution, etc. , to make sure the feasibility of this optimization method, and conclude the effect of hub ratio to the fan performance. The results show that the energy loss brought by vortex is reduced on fan blades and hub surface after optimization, while the vortex and energy loss on tip are increased slightly. In different flow,there are varied improvements on fan static pressure and outlet velocity after optimization. Under the rating conditions, the fan performance, static characteristic and internal flow field have good improvement.