Helmholtz共振腔气动噪声数值仿真

为探究出一套完整、准确的气动噪声仿真方法,用FLUENT和Actran仿真Helmholtz共振腔旁接管道系统模型.针对流场仿真,采用六面体网格建模,分析选择合适的网格密度,明确网格及边界条件的影响,以获得准确的声源信息;运用Lighthill声类比方法对声场进行仿真,采用数值计算、传声损失仿真和气动噪声仿真计算等3种方法提取管道内部场点声压级频谱曲线,分析曲线峰值频率特征,包括共振频率分析和声模态分析等.采用CFD软件与声学仿真软件相结合的方法,可以有效进行流场和声场的仿真.

Numerical simulation on aerodynamic noise of Helmholtz resonator

To find out a set of complete and accurate aerodynamic noise simulation method, the aerodynamic noise of Helmholtz resonator next to a piping system model is simulated using FLUENT and Actran. For the simulation of flow field, the hexahedral meshes are used for modeling, a suitable mesh density is selected by analysis, the influence of the mesh and boundary conditions is determined, and the accurate acoustic source can be obtained. For the simulation of acoustic field by Lighthill acoustic analog method, three methods including numerical calculation, transmission loss simulation and aerodynamic noise simulation are used to extract the frequency spectrum curves of acoustic pressure level of the pipeline internal field points, and the peak frequency characteristics are analyzed including the analysis on resonance frequency and acoustic mode. The flow field and acoustic field can be effectively simulated by the method of combining CFD software with acoustics simulation software.