叶顶端板结构参数对小型轴流风扇静特性和噪声的影响

发布时间：2018-02-28 21:20

本文关键词： 小型轴流风扇端板静特性气动噪声实验　出处：《浙江理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：小型轴流风扇作为电子产品重要的散热部件,其通风性能将严重影响产品的散热效果和使用寿命,产生的气动噪声也会对人们的工作环境造成负面影响。因此,对小型轴流风扇的性能进行研究具有重要的工程意义。本文在小型轴流风扇的基础上,沿扇叶压力面添加叶顶端板;用数值模拟的方法研究了叶顶端板宽度和弦向长度对风扇静特性、噪声和内部流动特性的影响;并对原型风扇和降噪效果最好的改型风扇进行了实验测试。论文的主要内容和成果如下:(1)以小型轴流风扇为研究对象,运用逆向工程建立风扇的三维几何模型;在扇叶压力面沿弦向添加叶顶端板,得到带不同宽度和弦向长度叶顶端板的改型风扇;简述了计算域的划分、数值模拟方法和噪声预测模型的选择。(2)设计了不同宽度的叶顶端板和不同弦向长度的叶顶端板,分析原型风扇和改型风扇的静特性和内部流动特性,结果表明:添加叶顶端板在一定程度上会降低风扇的静特性,对风扇的通风性能有负面影响。叶顶端板可以增加风扇出口面下游空气的流速,减少叶顶区域附近涡的产生,在一定程度上改善叶顶区域的内部流动状况。(3)设计了不同宽度的叶顶端板和不同弦向长度的叶顶端板,分析原型风扇和改型风扇的噪声特性,结果表明:带2 mm宽度叶顶端板的改型风扇在远场处噪声较原型风扇噪声降低1.2 dB,为本研究中最佳的叶顶端板宽度。带4/5弦向长度叶顶端板的改型风扇在远场处的噪声较原型风扇噪声降低2.4 dB,为本研究中最佳的叶顶端板弦向长度。添加叶顶端板对风扇近场的降噪没有积极效果。(4)对原型风扇和添加2 mm宽度、4/5弦向长度叶顶端板的改型风扇进行静特性和噪声测试。静特性测试结果表明,改型风扇的静特性略低于原型风扇;噪声测试结果表明,改型风扇远场噪声较原型风扇远场噪声明显下降。实验测试结果与数值模拟结果吻合,说明数值模拟具有一定的可靠性。
[Abstract]:As an important heat dissipation component of electronic products, the ventilation performance of small axial fan will seriously affect the heat dissipation effect and service life of the product, and the aerodynamic noise will also have a negative impact on the working environment of people. It is of great engineering significance to study the performance of small axial flow fan. In this paper, the blade top plate is added along the blade pressure surface on the basis of small axial flow fan. The effects of the width and chord length of the blade tip plate on the static characteristics, noise and internal flow characteristics of the fan are studied by numerical simulation. The prototype fan and the modified fan with the best noise reduction effect are tested. The main contents and results of this paper are as follows: 1) taking the small axial fan as the research object, the 3D geometry model of the fan is established by reverse engineering. A modified fan with different width and length of blade tip plate was obtained by adding blade top plate along the chord direction to the fan pressure surface, and the division of calculation domain was briefly described. Numerical simulation method and noise prediction model selection. 2) the tip plate with different width and the blade tip plate with different chord length are designed, and the static and internal flow characteristics of the prototype fan and modified fan are analyzed. The results show that the static characteristics of the fan will be reduced to some extent and the fan ventilation will be negatively affected by adding the blade top plate. The blade top plate can increase the flow velocity of the downstream air at the outlet of the fan and reduce the vortex generation near the top area of the fan. To some extent, to improve the internal flow condition in the top area of the blade, the tip plate with different width and the blade top plate with different chord length are designed, and the noise characteristics of the prototype fan and the modified fan are analyzed. The results show that the noise of the modified fan with 2 mm width blade tip plate is 1.2 dB lower than that of the prototype fan in the far field, which is the best blade top plate width in this study. The modified fan with 4/5 chord length blade tip plate is located in the far field. The noise of the fan is 2.4 dB lower than that of the prototype fan, which is the best chord length of the blade tip plate in this study. The addition of the blade tip plate has no positive effect on the noise reduction of the fan in the near field. 4) for the prototype fan and for the fan with 2 mm width and 4 / 5 chord length, the effect of the blade top plate on the noise reduction in the near field is not positive. The static characteristics and noise of the modified fan of the top plate are tested. The static characteristic of the modified fan is slightly lower than that of the prototype fan, and the noise test results show that the far field noise of the modified fan is obviously lower than that of the prototype fan, and the experimental results are in agreement with the numerical simulation results. It shows that numerical simulation has certain reliability.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH432.1;TB53

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