离心压缩机机壳在基频气动力激励下的振动噪声研究

摘要

This paper has studied the vibration radiated noise of centrifugal compressor casing under the excitation of internal fundamental frequency aerodynamic. Considering the gap of casing with wheel disc and shroud, the turbulence model was used to simulate the 3D unsteady flow field of the centrifugal compressor, the fluctuating pressure on the internal surface of volute was obtained. Loading the fundamental frequency of fluctuating pressure on the volute, the simulation on vibration and noise of centrifugal compressor volute under the excitation of unsteady aerodynamic was carried out. The research shows that the fundamental frequency pressure pulsation on the inner wall of casing is mainly distributed on the side of vaneless diffuser near impeller outlet, the main fundamental frequency vibration and noise source of casing is located in the side of volute near outlet pipe. The fundamental frequency vibration displacement amplitude of the centrifugal compressor casing is very small that the maximum vibration displacement is only 11.8 × 10-9m. Therefore, the influence of fundamental frequency vibration of casing on the operating safety of centrifugal compressor can be neglected.%研究了离心压缩机机壳在内部基频气动力激励下的振动辐射噪声。考虑机壳与轮盘、轮盖之间的间隙，采用湍流模型模拟了离心压缩机的整机三维非定常流场，得到蜗壳内表面的脉动压力，然后将脉动压力的基频部分加载到蜗壳上，模拟离心压缩机蜗壳在非定常气动力激励下的振动噪声。研究表明：机壳内壁面基频压力脉动主要分布在无叶扩压器靠近叶轮出口一侧；机壳主要基频振动噪声源位于蜗壳靠近出口管道一侧；该离心压缩机机壳基频振动位移幅值很小，最大振动位移仅为11.8×10-9m，因此可以忽略机壳的基频振动对离心压缩机运行安全性的影响。