动叶安装角异常反向偏离对轴流风机性能的影响

摘要

以某OB-84型动叶可调轴流风机为例,采用Fluent软件模拟得到两异常叶片安装角反向偏离时的风机性能曲线,分析了异常叶片间的相位和安装角偏离度△β对总压、熵产率和噪声分布的影响.结果表明:动叶异常偏离时的风机全压和效率曲线明显偏离正常值,各流量系数下的最大声功率级整体提高；随着△β增大,风机性能显著下降,且与异常叶片间的相位关系有关；不同的异常叶片相位关系和△β对特征截面上的内流特征分布具有明显不同的影响,相间关系的异常叶片对内流特征的影响有叠加效应,相对关系的异常叶片对其附近及旋转方向下游流场的影响基本对称.%Taking the OB-84 variable pitch axial fan as an example,numerical simulation was carried out to study its performance curves using Fluent software under abnormal reverse deviation of two blades,so as to analyze the influence of deviation degree △β and phase of the two blades on the distribution of total pressure,entropy generation rate and acoustic source power level.Results show that under the reverse deviation of blade installation angle,the full pressure and efficiency are distinctly drifted from normal values,and the maximum value of acoustic power level tends to be raised under various flow coefficients.With the rise of △β,the fan performance is deteriorated obviously,which is closely related to the phase between abnormal blades.The internal flow characteristics on typical cross sections are remarkably influenced by the phase variation and △β.The additive effect of both abnormal blades with alternating phases on internal flow characteristics is clearly protruded,and the independent effect of blades with abnormal phases tends to be basically symmetrical on the internal flow distribution following and adjacent to the abnormal blades.