基于level set的Eulerian-Lagrangian耦合方法及其应用  

A COUPLED EULERIAN-LAGRANGIAN METHOD BASED ON LEVEL SET AND ITS APPLICATIONS

作　　者：贾祖朋[1] 蔚喜军[1] 

机构地区：[1]北京应用物理与计算数学研究所,计算物理实验室,北京100094

出　　处：《力学学报》2010年第2期177-182,共6页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金项目(10676004,10771019,10671025);国家重点基础研究发展计划(973)项目(2005CB321700);中国工程物理研究院科学技术基金项目(2008A0201009,2007A09006);计算物理重点实验室基金项目(9140C690101070C69)资助~~

摘　　要：提出了一种基于水平集的Eulerian-Lagrangian耦合方法,其中Lagrangian方法采用相容显式有限元拉氏方法,Eulerian方法采用基于近似Riemann解的有限体积Eulerian方法,多介质界面处理采用新的水平集和Ghost方法计算.给出了若干数值算例,包括激波管问题以及金属和气体的运动界面及其大变形问题,并分别与精确解和相容显式有限元拉氏方法的计算结果进行了对比.数值结果表明,该方法计算结果正确,精度较高,能够准确捕捉物质界面,适用于处理大变形问题.In this paper a coupled Eulerian-Lagrangian method based on level set for multi-material compressible fluid flow involving large deformation is presented.In the scheme,a Lagrangian method is used in the domain with small deformation while an Euler method is used in the domain with large deformation.The interface is treated by a new level set method and the Ghost Fluid method.Furthermore,an explicit compatible finite element method is employed as the Lagrangian method.In this Lagrangian method,the finite element method is used to discretize the fluid equations in terms of the framework of compatibility,an edge-centered artificial viscosity is used to capture shocks,and the subzonal perturbed pressure is used to resist spurious and unresolved grid motions.A vertex-centered finite volume method based on approximate Riemann solver is used as the Eulerian method.In this Eulerian method,an HLLC numerical flux adapted to various equations of state are employed,a second order accuracy in space is achieved by using a reconstruction of primitive variables based on WENO approach.An explicit two-stage Runge-Kutta time-stepping scheme is used in discretization of time.A new method to determine the signs of the level set function and a new technique to compute the velocities of the projection points of the Ghost points on the interface are proposed.Numerical examples show the accuracy as well as the robustness of the method.

关 键 词：大变形流体力学问题 多介质 Eulerian-Lagrangian耦合方法 水平集方法 近似Riemann解 

分 类 号：O241[理学—计算数学]