中文摘要：

应用旋转模态理论和CFD方法研究贯流叶轮的离散噪声特性,并分析贯流风机远场噪声主要呈现宽频的原因.设计了三种不同的蜗壳匹配方案,以控制贯流风机内主要的涡结构。通过采用CFD方法计算不同方案中贯流风机内部涡流动结构主要位置,确定出贯流叶轮上下游发生干涉的叶片数。根据模态分析理论,计算了不同蜗壳及蜗舌匹配方案中贯流叶轮的截止率。计算结果表明,由于叶轮内主流速度较低,使得贯流风机的离散噪声不明显。

英文摘要：

In this paper,the far field discrete frequency noise of the cross flow impeller was investigated by means of modal analysis methods and CFD.As a result,the mechanism of the broadband noise frequency emitted from cross flow fan was explored.Three different positions of backwall and tongue was implemented to control the main vortex structure in the cross flow fan.In order to figure out the numbers of blades between inflow stage and outflow stage,the position of large vortex structure in different cross flow fans were marked from the CFD results. The cut-on characteristics of the cross flow impeller were investigated by means of modal analysis. The results showed that the discrete noise of cross flow fan was low as the result of the low main stream.