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动叶可调轴流式风机因具有较宽的高效区而得到广泛应用。以OB-84型带后导叶的动叶可调轴流风机为对象,采用Fluent对单个动叶安装角处于3种异常状况下的叶轮内流特征进行了数值模拟,并分析了安装角异常变化对风机全压和效率特性曲线的影响。研究表明:随异常叶片安装角的增大,异常叶片后缘处的尾迹损失增加,压力面压力梯度从前缘到后缘逐渐减小,而吸力面压力梯度增大并在后缘产生旋涡;叶轮出口的低压区范围扩大而总压值减小,异常叶片引起的流动损失主要集中在叶高中部位置;风机全压呈现先增大后减小的趋势,当异常叶片安装角增加为6°、12°和18°时,风机内效率下降分别为2.9%、4.8%和9.1%。
Adjustable axial fan blades due to a wide range of high efficiency and has been widely used. In this paper, an object-oriented adjustable-blade axial-flow fan with OB-84 with guide vanes is adopted. Fluent is used to simulate the characteristics of impeller flow in three abnormal conditions. Effect of Variation on Total Pressure and Efficiency Curve of Fan. The results show that with the increase of abnormal blade mounting angle, the wake loss at the trailing edge of the abnormal blade increases, the pressure gradient of the pressure surface decreases from the leading edge to the trailing edge, and the pressure gradient of the suction surface increases and the vortex forms on the trailing edge. The range of low-pressure zone at exit increases and the total pressure decreases. The flow loss caused by abnormal blades is mainly concentrated in the middle of leaf height. The total pressure of fan increases first and then decreases. When the installation angle of abnormal blades increases by 6 °, 12 ° and 18 °, the fan efficiency decreased by 2.9%, 4.8% and 9.1% respectively.