【摘要】 以小型轴流风扇为原型,对其叶片进行穿孔设计,采用k-ε两方程湍流模型和大涡模拟数值分析风扇的内部流场,对比分析原型风扇和叶片穿孔以后风扇的静特性和气动声学特性。结果显示:叶片穿孔后,在整个计算流量下,风扇的静压升稍有下降,但在最佳工况点时,风扇的静压升基本上和原型风扇相当;涡脱落位置更靠近叶顶;在出口区,涡流消失点向下游移动、涡量减弱,风扇的噪声整体减小,但在不同的频段噪声降低幅度不同,在35～45kHz频率范围内,噪声降低幅度最大。这些研究结果说明,在风扇最佳工况点下采用叶片穿孔方法来降低噪声的方法是可行的。更多还原

【Abstract】 By using a certain type of small fans as prototype,this thesis designs a fan model with perforation blades and uses N-S equations coupled with κ-ε turbulence model to simulate the three-dimensional flow field of small axial flow fans.In addition,it analyzes static characteristics and pneumatic acoustic characteristics of the two fans based on the results of numerical simulation.The results show,as a leaf perforation fan,the static pressure decreases in the whole calculation flow but rises just the same as the prototype fan at the best condition point;the position of vortex shedding is closer to the blade tip,vanishing point of vortex moves downstream in the export zones eddy and vorticity weakens,so all the noise of the fan decreases.However,there is a different noise reduction at different frequency bands and the noise reduction is the largest in the 35～45 kHz frequency range.These results suggest that using some fan blade perforation methods to reduce the noise is feasible on the best condition.更多还原