船舶汽轮机蒸汽管路流动噪声源的声类比计算研究

针对某船舶动力系统蒸汽调节管路在不同阀门启闭状态下的流动噪声源空间分布,开展了详细的计算气动声学数值研究工作。采用剪切应力输运湍流模型(SST,shear stress transport)获取了管内复杂三维蒸汽流场分布;结合Curle声类比模型和Proudman声类比模型分别计算得到管路壁面偶极子噪声源和管内流体域四极子噪声源分布特性。研究结果表明：相比于阀门关闭状态下的一进一出“T型”和“Z型”管路,阀门开启后的两进一出“h型”管路内流动噪声源强度上升明显;偶极子噪声源主要分布在管路汇聚处与出口弯管区域壁面,与此区域流体剪切应力相关;由于出口弯管直径突然变小,且流体流向发生变化,导致此处管内流场湍流度较高,故而产生了较为强烈的四极子噪声源。

Aeroacoustics Simulation of Flow Induced Noise Sources inside the Steam Pipeline of Marine Turbine System

Aiming at the spatial location of the aerodynamic noise sources in the steam regulating pipe of a marine power system under different valve opening and closing conditions, a detailed numerical study of computational aeroacoustics was carried out. Shear stress transport (SST) turbulence model was used to obtain the complex three dimensional steam flow field distribution in the pipe; combined with Curle acoustic analogy model and Proudman acoustic analogy model, the distribution characteristics of dipole noise source on the pipe wall and quadrupole noise source in the fluid domain of the pipe were calculated respectively. The research result shows that compared with T type and Z type pipelines with one inlet and one outletwhen the valve is closed, the intensity of aerodynamic noise source "h" type pipeline with two inlets and one outlet increases significantly after the valve is open. Among them, the dipole noise source is mainly distributed in the pipeline convergence and the wall of outlet elbow area, which is closely related to the local fluid shear stress. The quadrupole noise source is mainly located in the outlet elbow, which is strongly related to higher turbulent kinetic energy distribution of flow field in pipe caused by suddenly becoming small of elbow diameter and the change of flow direction.