中文摘要：

本文采用大涡模拟对空调室内机中贯流风机的内流进行了数值计算，结果显示了以偏心涡为代表的复杂非定常流动细节。计算结果表明，贯流风机气流两次进出叶轮，叶片尾缘、蜗舌处出现明显的脱落涡结构。叶轮周围监测点上出现了三个特征频率，分别对应叶片通过频率、叶片脱落涡频率以及蜗舌后缘的脱落涡频率，不同的特征点上表现出不同的频谱特性。另外，通过LEE方程中的声源项分布得到了贯流风机的主要噪声源区域，继而对蜗舌和叶轮等主要音源表面的远场辐射噪声频谱进行了分析，为后续的实验研究提供参考。

英文摘要：

The numerical analysis of internal flow structures in the cross flow fan used in indoor machine of air conditioner has been carried out by large eddy simulation. The results display complicate unsteady flow details, among which the eccentric vortex is the representation. The fluid passing through the cross flow fan traverses the impeller twice and there are distinct vortex shedding structures near the blade trailing edge and vortex wall. By monitoring static pressure of several characteristic points around the impeller, three characteristic frequencies are acquired. They correspond to blade passing frequency, vortex shedding frequency of blade and vortex wall, respectively. So the different spectrum characteristics are presented at different characteristic points. In addition, the main noise source region of cross flow fan is obtained by acoustic source in LEE equations, and the spectrum of far-field noise radiated from the main acoustic source surfaces including the impeller and vortex wall is analysed, which will be reference for the further experimental research.