空调通风系统管道气动噪声分析

Analysis of Pipeline Aerodynamic Noise of HVAC

针对船舶通风空调系统的管道噪声问题,分别利用CFD进行流体动力学仿真和FEM进行声学有限元仿真分析,结果表明,管道气动噪声的生成原因是大量不规则湍流运动形成负压区并生成气流漩涡和回流,从而造成变化剧烈的压力脉动。模拟中以等效壁面偶极子声源的方式计算辐射噪声,通过分析出口的声压级频率响应判断管道气动噪声是噪声能量主要集中在中低频的宽频噪声,管道内流速和内部结构变化是影响噪声大小的主要原因。

In order to meet the growing demand for domestic acoustic comfort of vessels,aiming at one of the main aerodynamic noise sources of HVAC in vessels,namely Aiming at the pipeline aerodynamic noise in HVAC system,the computational fluid dynamics（ CFD） and the finite element method（ FEM） were respectively applied for hydrodynamics simulation and acoustics simulation. It was found that the cause of pipeline aerodynamic noise is that a large amount of irregular turbulent flow motions form negative pressure zone,so as to generate vortex and reflux,resulting severe pressure fluctuations. The wall dipole source was taken to calculate radiated noise. According to the frequency responding curve at the outlet,the pipeline aerodynamic noise was found to be a kind of wide frequency noise whose energy is mainly concentrated on the low-medium frequency; the change of flow velocity and internal structure in the pipeline is the main reason that affects the magnitude of noise.