间断伽辽金玻尔兹曼方法中的基于完全耦合层技术的吸收边界条件研究  

An Absorbing Boundary Condition Based on the Perfectly Matched Layer Technique in Discontinuous Galerkin Boltzmann Method

作　　者：邵卫东[1] 李军[1] SHAO Wei-Dong;LI Jun(Institute of Tiirbomachinery X^an Jiaotong University,Xi'an 710049,China)

机构地区：[1]西安交通大学叶轮机械研究所,西安710049

出　　处：《工程热物理学报》2019年第4期767-775,共9页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No.51776151)

摘　　要：本文发展了一种基于完全耦合层技术的吸收边界条件,并将其融合到具有低耗散和低色散性质的格子玻尔兹曼方法中。通过坐标变换保证了吸收边界条件的无条件稳定,通过解耦时间积分方法实现了交点间断伽辽金有限元方法求解对流过程。采用二维高斯脉动波和等温涡对迁移两个算例研究了完全耦合层厚度、指数分布因子和最大衰减系数对边界无反射能力的影响,采用双腔流噪声算例研究了吸收边界条件的长时间稳定性和非均匀伪平均流的有效性。结果表明本文发展的吸收边界条件表现良好,并可将其进一步发展到实际气动噪声计算问题中。An absorbing boundary condition based on the perfectly matched layer technique is developed. It is combined with lattice Boltzmann method, which has low dissipative and low dispersive properties. By means of the coordinate transformation, unconditional stability is ensured. Invoking the decoupling time integration, we can solve the streaming process with nodal discontinuous Galerkin method. Two-dimensional Gauss waves and isothermal vortex migration are used to study the effect of layer thickness, index and maximum decaying coefficient on the non-reflecting performance. Double cavity flow noise is used to study the long time stability and the inhomogeneous pseudo mean flow.The result shows good performance, indicating the application of the absorbing boundary condition to real-life computational aeroacoustics.

关 键 词：吸收边界条件 完全耦合层 交点间断伽辽金方法 计算气动声学 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]