A Krylov space based time domain method for wave propagation problems is introduced. The proposed method uses the Arnoldi algorithm to obtain broad-band frequency domain solutions. This method is especially advantageo...A Krylov space based time domain method for wave propagation problems is introduced. The proposed method uses the Arnoldi algorithm to obtain broad-band frequency domain solutions. This method is especially advantageous in cases where slow convergence is observed when using traditional time domain methods. The efficiency of the method is examined in several test cases to show its fast convergence in such problems.展开更多
We study a class of preconditioners to solve large-scale linear systems arising from fully implicit reservoir simulation.These methods are discussed in the framework of the auxiliary space preconditioning method for g...We study a class of preconditioners to solve large-scale linear systems arising from fully implicit reservoir simulation.These methods are discussed in the framework of the auxiliary space preconditioning method for generality.Unlike in the case of classical algebraic preconditioning methods,we take several analytical and physical considerations into account.In addition,we choose appropriate auxiliary problems to design the robust solvers herein.More importantly,our methods are user-friendly and general enough to be easily ported to existing petroleum reservoir simulators.We test the efciency and robustness of the proposed method by applying them to a couple of benchmark problems and real-world reservoir problems.The numerical results show that our methods are both efcient and robust for large reservoir models.展开更多
This paper presents an absorbing boundary condition for molecular dynamics simulations of materials defects.The purpose of the boundary condition is to eliminates spurious reflections of phonons at the boundary and mi...This paper presents an absorbing boundary condition for molecular dynamics simulations of materials defects.The purpose of the boundary condition is to eliminates spurious reflections of phonons at the boundary and minimize the finite size effect.In contrast to other existing methods,our emphasis is placed on the ease of implementation.In particular,we propose a method for which the implementation can be done within existing molecular dynamics code,and it is insensitive to lattice structure,the geometry and space dimension of the computational domain.To demonstrate the effectiveness,the results from two test problems are presented.展开更多
文摘A Krylov space based time domain method for wave propagation problems is introduced. The proposed method uses the Arnoldi algorithm to obtain broad-band frequency domain solutions. This method is especially advantageous in cases where slow convergence is observed when using traditional time domain methods. The efficiency of the method is examined in several test cases to show its fast convergence in such problems.
基金supported by Petro-China Joint Research Funding(Grant No.12HT1050002654)National Science Foundation of USA(Grant No.DMS-1217142)+1 种基金the Dean’s Startup FundAcademy of Mathematics and System Sciences and the State High Tech Development Plan of China(863 Program)(GrantNo.2012AA01A309)
文摘We study a class of preconditioners to solve large-scale linear systems arising from fully implicit reservoir simulation.These methods are discussed in the framework of the auxiliary space preconditioning method for generality.Unlike in the case of classical algebraic preconditioning methods,we take several analytical and physical considerations into account.In addition,we choose appropriate auxiliary problems to design the robust solvers herein.More importantly,our methods are user-friendly and general enough to be easily ported to existing petroleum reservoir simulators.We test the efciency and robustness of the proposed method by applying them to a couple of benchmark problems and real-world reservoir problems.The numerical results show that our methods are both efcient and robust for large reservoir models.
文摘This paper presents an absorbing boundary condition for molecular dynamics simulations of materials defects.The purpose of the boundary condition is to eliminates spurious reflections of phonons at the boundary and minimize the finite size effect.In contrast to other existing methods,our emphasis is placed on the ease of implementation.In particular,we propose a method for which the implementation can be done within existing molecular dynamics code,and it is insensitive to lattice structure,the geometry and space dimension of the computational domain.To demonstrate the effectiveness,the results from two test problems are presented.
