无网格方法是近年来国内外学术界及工程领域的研究热点，被广泛应用于固体力学，动力学以及流体力学的研究，在声学的应用较少。管道声学是一种常见的工程问题，研究噪声在管道流动介质中的传播和衰减特性是声学设计和噪声控制的基础。本课题使用无网格方法研究管道伴流声场特性，根据结构特点或填充材料的不同将管道划分成不同子域，使用二维无网格法和模态匹配法结合形成半解析方法求解规则结构子域声场，采用三维径向点插值配点型无网格方法求解不规则结构子域声场。探索无网格形参函数、配点方案以及导数边界条件的处理技术对管道伴流声场计算精度的影响，实现无网格-半解析耦合技术研究不规则管道三维伴流声场特性的目标，为无网格法在管道声学领域的广泛应用奠定基础。

Meshless method has been paid very much attention by scientists and engineers in various computational researches in the recent years. It has been widely applied in the solid mechanics, dynamics and fluid mechanics, but less applied in acoustics investigation. Duct acoustics is a common problem in engineering, and the computation and analysis of noise propagation and attenuation characteristics in duct with flow medium are foundation and preparative works for acoustic design and noise control. The meshless method is used to investigate the acoustics characteristics of the convective sound filed in the present project. The duct is divided into several subdomains based on the structure features and material properties. The acoustic characteristics of the regular subdomain is investigated by semi-analytical method combination with the 2-D meshless method and 3-D mode matching method, and the acoustic characteristics of the irregular subdomain is investigated by the 3-D radial point interpolation collocation meshless method. The main works include studies on effects of the parameter function, the collocation design and derivative boundary condition processing technology on the computation of the convective sound filed. The objective of the present project is to develop a coupling approach of meshless method and semi-analytical method for the computation of convective sound filed problem, and to establish the foundation for the further research on the application of meshless method in the duct acoustic problem.