高效低噪声离心式通风机的数值模拟与优化设计

发布时间：2018-03-12 11:12

本文选题：离心式通风机　切入点：数值模拟　出处：《沈阳工业大学》2012年硕士论文　论文类型：学位论文

【摘要】：离心式通风机是一种通用的叶轮机械,因其体积小和压力系数高被广泛应用于引流工程。本文采用数值模拟分析的方法,对离心通风机三维流场进行了模拟,分析研究了风机内部流动情况。首先建立离心式通风机三维模型,把叶轮流域设为转动区域,把进风口和蜗壳设为静止区域。采用非结构化网格对其分网;采用有限体积法对偏微分方程组进行离散;在三维时均N ? S方程和标准k ?ε两方程湍流涡粘模型的基础上,采用SIMPLE算法,对离心式通风机内部整机流场进行数值模拟,通过分析风机内部流动情况,确定了湍流强度大、噪声高的两个部位:叶轮进口和蜗舌处;同时还捕捉到了叶道内二次流、叶道出口的射流和尾迹和蜗壳内的涡流等现象。其次,分析研究了强湍流部位:叶轮进口和蜗舌。进风口匹配与否是影响叶片入口处气流速度分布和涡流噪声的主要因素,而影响进风口形状的主要参数是张开角的大小。本文建立了进风口张开角和叶片入口处气流速度之间的关系模型,通过对比不同进口张开角下叶片入口处气流速度方差,确定了与本风机最匹配的进口张开角为14°;蜗舌相对间隙δr2是影响风机有调噪声的主要因素,本文通过对比分析不同相对间隙下蜗舌处等声线的变化,确定了最佳蜗舌相对间隙为12 %。根据数值模拟结果,设计制造出了一台风机,对它进行了性能和噪声试验。实验验证了数值模拟结果是准确可信的,且该风机性能优良,噪声低。
[Abstract]:Centrifugal fan is a kind of universal impeller machine, which is widely used in drainage engineering because of its small volume and high pressure coefficient. In this paper, the three-dimensional flow field of centrifugal fan is simulated by numerical simulation. The flow inside the fan is analyzed and studied. Firstly, the three-dimensional model of centrifugal fan is established, the impeller basin is set up as rotation area, the inlet and volute are set as static area, its network is divided by unstructured grid, and the partial differential equations are discretized by finite volume method. In three dimensional time-averaged N? S equation and standard k? On the basis of 蔚 two-equation turbulent vortex-viscosity model, SIMPLE algorithm is used to simulate the flow field of the whole centrifugal fan. By analyzing the flow inside the fan, it is determined that the turbulence intensity is large. At the same time, the secondary flow in the impeller, the jet and wake at the outlet of the impeller and the eddy current in the volute are also captured. Secondly, the impeller inlet and cochlear tongue are analyzed and studied. The matching of the inlet and the inlet is the main factor affecting the velocity distribution and eddy current noise at the blade entrance. The main parameter affecting the shape of the inlet is the size of the opening angle. In this paper, the relationship between the opening angle of the inlet and the airflow velocity at the inlet of the blade is established, and the variance of the airflow velocity at the inlet of the blade under different inlet opening angles is compared. The inlet opening angle of the fan is determined to be 14 掳, and the relative gap of the cochlear tongue 未 R2 is the main factor affecting the adjustable noise of the fan. In this paper, the changes of the isobaric sound in the cochlea tongue under different relative gaps are compared and analyzed. The optimum relative space of cochlear tongue is 12 parts. According to the numerical simulation results, a typhoon machine is designed and manufactured, and its performance and noise are tested. The experimental results show that the numerical simulation results are accurate and reliable, and the fan has good performance and low noise.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH432

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