摘要
叶片加长是工程中提高风机出力的常用方法之一。为研究风机叶片加长后的内流特征,以G4–73型离心风机为研究对象,采用FLUENT软件分别对叶片加长前、后的离心风机进行三维定常数值模拟,分析流动变化对风机性能参数的影响规律。在此基础上,对叶轮叶片加长前、后的G4–73№.8D离心通风机进行性能和噪声实验,得到实验风机在叶轮叶片加长后运行工况点的变化规律及无因次性能曲线。性能实验结果与切割定律计算结果的比较表明,当风机叶轮叶片加长后且叶轮出口宽度不变时,按抛物线形切割定律计算的结果在大流量区误差较小。噪声实验结果表明,叶轮叶片加长后,叶轮与蜗舌间距离减少,导致旋转噪声升高,同时蜗壳内流动恶化,也使涡流噪声加大。文中所得研究结果可为工程实际中风机的叶片加长改造提供参考依据。
Blade tip lengthening is widely used to increase flowrate and pressure of centrifugal fan in engineering.In order to obtain the internal flow characteristics of the centrifugal fan with lengthened blade tip,the three-dimensional numerical simulation of the G4-73 centrifugal fan was carried out using FLUENT.The variation of flow characteristics and its effect on operating parameters were investigated.The performance and acoustic experiments of the G4-73№.8D fan with and without lengthened blade tip were conducted.The transform laws of the operation points and dimensionless performance curves of the fan with blade tip lengthened were obtained from the experiment results.Comparison between experimental results and the trimming law shows that the parabolic trimming law is agreement with the experiment results in larger flowrate region under the condition that the width of impeller outlet unchanged after the blade tip lengthening.The acoustic experiment shows that the discrete frequencies noise increases resulted by the decreased distance between impeller and volute tongue as well as the broadband noise increases because the worsening flow in the volute after blade lengthen.The present results can be used to determine the value to be lengthened of the centrifugal fan in modification.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2010年第20期71-78,共8页
Proceedings of the CSEE
基金
中央高校基本科研业务费专项基金资助(09QX67)~~
关键词
离心风机
叶片加长
切割定律
内流特征
旋转噪声
涡流噪声
centrifugal fan
blade tip lengthening
trimming law
flow characteristics
discrete frequencies noise
broadband noise
