The weak Galerkin(WG)method is a nonconforming numerical method for solving partial differential equations.In this paper,we introduce the WG method for elliptic equations with Newton boundary condition in bounded doma...The weak Galerkin(WG)method is a nonconforming numerical method for solving partial differential equations.In this paper,we introduce the WG method for elliptic equations with Newton boundary condition in bounded domains.The Newton boundary condition is a nonlinear boundary condition arising from science and engineering applications.We prove the well-posedness of the WG scheme by the monotone operator theory and the embedding inequality of weak finite element functions.The error estimates are derived.Numerical experiments are presented to verify the theoretical analysis.展开更多
This article is devoted to studying the application of the weak Galerkin(WG)finite element method to the elliptic eigenvalue problem with an emphasis on obtaining lower bounds.The WG method uses discontinuous polynomi...This article is devoted to studying the application of the weak Galerkin(WG)finite element method to the elliptic eigenvalue problem with an emphasis on obtaining lower bounds.The WG method uses discontinuous polynomials on polygonal or polyhedral finite element partitions.The non-conforming finite element space of the WG method is the key of the lower bound property.It also makes the WG method more robust and flexible in solving eigenvalue problems.We demonstrate that the WG method can achieve arbitrary high convergence order.This is in contrast with existing nonconforming finite element methods which can provide lower bound approximations by linear finite elements.Numerical results are presented to demonstrate the efficiency and accuracy of the theoretical results.展开更多
The linear hyperbolic equation is of great interest inmany branches of physics and industry.In this paper,we use theweak Galerkinmethod to solve the linear hyperbolic equation.Since the weak Galerkin finite element sp...The linear hyperbolic equation is of great interest inmany branches of physics and industry.In this paper,we use theweak Galerkinmethod to solve the linear hyperbolic equation.Since the weak Galerkin finite element space consists of discontinuous polynomials,the discontinuous feature of the equation can be maintained.The optimal error estimates are proved.Some numerical experiments are provided to verify the efficiency of the method.展开更多
In this paper,we propose a new numerical scheme for the coupled Stokes-Darcy model with the Beavers-Joseph-Saffman interface condition.We use the weak Galerkin method to discretize the Stokes equation and the mixed fi...In this paper,we propose a new numerical scheme for the coupled Stokes-Darcy model with the Beavers-Joseph-Saffman interface condition.We use the weak Galerkin method to discretize the Stokes equation and the mixed finite element method to discretize the Darcy equation.A discrete inf-sup condition is proved and the optimal error estimates are also derived.Numerical experiments validate the theoretical analysis.展开更多
This paper proposes and analyzes a new weak Galerkin method for the eigenvalue problem by using the shifted-inverse power technique.A high order lower bound can be obtained at a relatively low cost via the proposed me...This paper proposes and analyzes a new weak Galerkin method for the eigenvalue problem by using the shifted-inverse power technique.A high order lower bound can be obtained at a relatively low cost via the proposed method.The error estimates for both eigenvalue and eigenfunction are provided and asymptotic lower bounds are shown as well under some conditions.Numerical examples are presented to validate the theoretical analysis.展开更多
In this paper,we solve linear parabolic integral differential equations using the weak Galerkin finite element method(WG)by adding a stabilizer.The semidiscrete and fully-discrete weak Galerkin finite element schemes ...In this paper,we solve linear parabolic integral differential equations using the weak Galerkin finite element method(WG)by adding a stabilizer.The semidiscrete and fully-discrete weak Galerkin finite element schemes are constructed.Optimal convergent orders of the solution of the WG in L^(2) and H^(1) norm are derived.Several computational results confirm the correctness and efficiency of the method.展开更多
基金China Postdoctoral Science Foundation through grant 2019M661199 and Postdoctoral Innovative Talent Support Program(BX20190142)Q.Zhai was partially supported by National Natural Science Foundation of China(12271208,11901015)+1 种基金R.Zhang was supported in part by National Natural Science Foundation of China(grant 11971198,11871245,11771179,11826101)the Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education of China(housed at Jilin University).
文摘The weak Galerkin(WG)method is a nonconforming numerical method for solving partial differential equations.In this paper,we introduce the WG method for elliptic equations with Newton boundary condition in bounded domains.The Newton boundary condition is a nonlinear boundary condition arising from science and engineering applications.We prove the well-posedness of the WG scheme by the monotone operator theory and the embedding inequality of weak finite element functions.The error estimates are derived.Numerical experiments are presented to verify the theoretical analysis.
基金supported in part by China Natural National Science Foundation(91630201,U1530116,11771179)by the Program for Cheung Kong Scholars of Ministry of Education of China,Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education,Jilin University,Changchun,130012,P.R.China+3 种基金supported in part by the National Natural Science Foundation of China(NSFC 11471031,91430216)and the U.S.National Science Foundation(DMS–1419040)supported by Science Challenge Project(No.TZ2016002)National Natural Science Foundations of China(NSFC 11771434,91330202,11371026,91430108,11771322,11626033,11601368)the National Center for Mathematics and Interdisciplinary Science,CAS.
文摘This article is devoted to studying the application of the weak Galerkin(WG)finite element method to the elliptic eigenvalue problem with an emphasis on obtaining lower bounds.The WG method uses discontinuous polynomials on polygonal or polyhedral finite element partitions.The non-conforming finite element space of the WG method is the key of the lower bound property.It also makes the WG method more robust and flexible in solving eigenvalue problems.We demonstrate that the WG method can achieve arbitrary high convergence order.This is in contrast with existing nonconforming finite element methods which can provide lower bound approximations by linear finite elements.Numerical results are presented to demonstrate the efficiency and accuracy of the theoretical results.
基金The research of R.Zhangwas supported in part by China Natural National Science Foundation(U1530116,91630201,11471141)by the Program for Cheung Kong Scholars of Ministry of Education of China,Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education,Jilin University,Changchun,130012,P.R.China.
文摘The linear hyperbolic equation is of great interest inmany branches of physics and industry.In this paper,we use theweak Galerkinmethod to solve the linear hyperbolic equation.Since the weak Galerkin finite element space consists of discontinuous polynomials,the discontinuous feature of the equation can be maintained.The optimal error estimates are proved.Some numerical experiments are provided to verify the efficiency of the method.
基金National Natural Science Foundation of China(Grant Nos.11901015,11971198,91630201,11871245,11771179 and 11826101)the Program for Cheung Kong Scholars(Grant No.Q2016067)Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education,Jilin University。
文摘In this paper,we propose a new numerical scheme for the coupled Stokes-Darcy model with the Beavers-Joseph-Saffman interface condition.We use the weak Galerkin method to discretize the Stokes equation and the mixed finite element method to discretize the Darcy equation.A discrete inf-sup condition is proved and the optimal error estimates are also derived.Numerical experiments validate the theoretical analysis.
基金The work of Q.Zhai was partially supported by China Postdoc total Science Foundation(2018M640013,2019T120008)The work of X.Hu was partially supported by NSF grant(DMS-1620063)+1 种基金The work of R.Zhang was supported in part by China Natural National Science Foundation(91630201,11871245,11771179)by the Program for Cheung Kong Scholars of Ministry of Education of China,Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education,Jilin University,Changchun,130012,P.R.China.
文摘This paper proposes and analyzes a new weak Galerkin method for the eigenvalue problem by using the shifted-inverse power technique.A high order lower bound can be obtained at a relatively low cost via the proposed method.The error estimates for both eigenvalue and eigenfunction are provided and asymptotic lower bounds are shown as well under some conditions.Numerical examples are presented to validate the theoretical analysis.
基金supported in part by China Natural National Science Foundation(No.11901015)and China Postdoctoral Science Foundation(Nos.2018M640013 and 2019T120008)The research of Ran Zhang was supported in part by China Natural National Science Foundation(Nos.91630201,U1530116,11726102,11771179,93K172018Z01,11701210,JJKH20180113KJ and 20190103029JH)by the Program for Cheung Kong Scholars of Ministry of Education of China,Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education.
文摘In this paper,we solve linear parabolic integral differential equations using the weak Galerkin finite element method(WG)by adding a stabilizer.The semidiscrete and fully-discrete weak Galerkin finite element schemes are constructed.Optimal convergent orders of the solution of the WG in L^(2) and H^(1) norm are derived.Several computational results confirm the correctness and efficiency of the method.
