【作者】 雷海波；

【导师】 蔡兆麟；

【作者基本信息】 华中科技大学 ， 流体机械及工程， 2006， 硕士

【摘要】 多翼离心风机具有大流量系数、大压力系数、小尺寸系数以及低噪声等突出优点,被广泛应用于空调行业中。运用现有的、较成熟的CFD商业软件对风机内部流场进行数值计算分析,已逐渐成为一种重要的技术手段。本文进行了CFD前处理方面的开发。根据CFD参与现代叶轮机械的要求,在深刻理解、熟悉了大型建模参数化软件GAMBIT的基础上,采用面向对象技术和数据库技术,对GAMBIT软件进行捆绑式的二次开发。利用该建模参数化软件能够快速生成各种结构参数的多翼风机模型,大大节省了多翼离心风机前处理的时间。利用建模参数化软件对十多种多翼风机在设计点进行了CFD数值模拟,与样本数据比较表明模拟值与试验值比较吻合。同时,对影响本文CFD分析精度的各种主要误差来源进行了讨论。在此基础上,对一款优良的机型进行了工况范围内的数值模拟。全面、准确地获得了多翼离心风机的内部流场信息,形象地再现了风机内部的流动情景。研究表明,多翼风机的内部流场呈现出非常复杂的三维特性。以此为基础,分别从电机、蜗壳宽度、叶轮宽度、蜗壳扩张度以及间隙等外部结构参数以及叶轮内径、叶片进出口安装角、叶片弦长、叶片数等叶轮参数两大方面进行了数值计算,对不同结构参数改变引起的内部流场以及风机损失的变化进行了分析和讨论,得出的一些有益的结论,为今后多翼离心风机的结构优化设计提供参考依据。最后,讨论了作为风机数值模拟“后处理”之一的性能曲线绘图程序的开发。概述了性能曲线系统的算法依据、主要结构以及程序执行流程。对程序编制过程中遇到的主要问题以及一些关键技术给出了详细解释说明。更多还原

【Abstract】 Multi-blade centrifugal fan has been widely used for air-conditional system because of its high flow coefficient, high pressure coefficient, small size and low noise. It has gradually been an important technical means to predict the internal flow structure of fan by using an existing, mature, commercial CFD package.Based on the requirement of CFD application in modern turbo-machine and grasping GAMBIT that is a commercial preprocess code, the parameterized modeling program for multi-blade centrifugal fan utilizes OOP and database technologies to develop binding GAMBIT. By the parameterized modeling program, many kinds of multi-blade fans can be generated quickly, which helps to decline the time cost in developing new fans.With the developed program, about ten common multi-blade centrifugal fans are simulated by CFD at design flow condition. Compared with the real tests, a good agreement is found at designing flow condition. At the same time, the error sources affecting the accuracy of CFD are discussed. And then, on the forementioned base, a common fan is simulated at all flow condition, and a comprehensive visualization is successfully executed to gain detailed flow field information and clear understanding of the entire flow field throughout this multi-blade forward-curved centrifugal fan. Calculation results disclose that the flow in the fan shows complicated three-dimensional characteristics. On this base,the similar numerical methods are carried out to understand the basic flow physics and the effect of various parameters such as the motor, the width of the volute, the width of the impeller, the distender of the volute, the clearance, the blade outlet angle, inlet angle, the blade chord length and the number of the blade. The internal flow field and loss of the fans are predicted and discussed. Some instructive conclusions have been derived from the simulate results. Which will be helpful to improve the performance of multi-blade centrifugal fan.Finally, the development work of the program which is to draw fan performance curves and which is a“post-process”for CFD simulation is discussed. Mainly talks about the arithmetic, the structure and the executive process of the curve drawing system. Then discusses some problems and key techniques which are encountered during the development of the program.更多还原