Abstract
Supercloseness and postprocessing of the linear finite element method are studied on the Bakhvalov-type mesh for a singularly perturbed convection diffusion problem. Finite element analysis on this kind of mesh has always been an open problem. The difficulties arise from the width \(\mathcal {O}(\varepsilon \ln (1/\varepsilon ) )\) of subdomain for the layer and nonuniformity of meshes in the layer. A novel interpolation is introduced to address difficulties from the width of subdomain for the layer. As a result, supercloseness of order two is obtained for the linear finite element method. Based on this supercloseness result, we propose and analyze a new postprocessing operator according to the mesh’s structure. Its stability is proved by means of numerical quadrature. Then, it is proved that the numerical solution after postprocessing converges second order. Numerical experiments verify these theoretical results.
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References
Bakhvalov, N.S.: On the optimization of the methods for solving boundary value problems in the presence of a boundary layer. Zh. Vychisl. Mat. Mat. Fiz. 9, 841–859 (1969)
Benzi, M., Golub, G.H., Liesen, J.: Numerical solution of saddle point problems. Acta Numer. 14, 1–137 (2005)
Brenner, S.C., Scott, L.R.: The Mathematical Theory of Finite Element Methods Texts in Applied Mathematics, 3rd edn., vol. 15. Springer, New York (2008). https://doi.org/10.1007/978-0-387-75934-0
Ciarlet, P.G.: The Finite Element Method for Elliptic Problems Classics in Applied Mathematics, vol. 40. Society for Industrial and Applied Mathematics (SIAM), Philadelphia (2002). https://doi.org/10.1137/1.9780898719208
Franz, S., Linß, T.: Superconvergence analysis of the Galerkin FEM for a singularly perturbed convection–diffusion problem with characteristic layers. Numer. Methods Partial Diff. Equ. 24(1), 144–164 (2008)
Lin, Q., Yan, N., Zhou, A.: A rectangle test for interpolated finite elements. In: Proc. Syst. Sci. Eng., pp. 217–229. Great Wall (H.K.) Culture Publish Co (1991)
Linß, T.: Analysis of a Galerkin finite element method on a Bakhvalov-Shishkin mesh for a linear convection-diffusion problem. IMA J. Numer. Anal. 20(4), 621–632 (2000). https://doi.org/10.1093/imanum/20.4.621
Linß, T.: Uniform superconvergence of a Galerkin finite element method on Shishkin-type meshes. Numer. Methods Partial Diff. Equ. 16(5), 426–440 (2000). https://doi.org/10.1002/1098-2426(200009)16:5<426::AID-NUM2>3.3.CO;2-I
Linß, T.: Layer-adapted meshes for convection-diffusion problems. Comput. Methods Appl. Mech. Engrg. 192(9–10), 1061–1105 (2003). https://doi.org/10.1016/S0045-7825(02)00630-8
Linß, T.: Layer-Adapted Meshes for Reaction-Convection-Diffusion Problems. Lecture Notes in Mathematics, vol. 1985. Springer, Berlin (2010). https://doi.org/10.1007/978-3-642-05134-0
Liu, X., Zhang, J.: Galerkin finite element methods for convection-diffusion problems with exponential layers on Shishkin triangular meshes and hybrid meshes. Appl. Math. Comput. 307, 244–256 (2017). https://doi.org/10.1016/j.amc.2017.03.003
Liu, X., Zhang, J.: Uniform supercloseness of Galerkin finite element method for convection-diffusion problems with characteristic layers. Comput. Math. Appl. 75(2), 444–458 (2018). https://doi.org/10.1016/j.camwa.2017.09.028
Roos, H., Stynes, M., Tobiska, L.: Robust Numerical Methods for Singularly Perturbed Differential Equations Springer Series in Computational Mathematics, 2nd edn., vol. 24. Springer, Berlin (2008)
Roos, H.G.: Error estimates for linear finite elements on Bakhvalov-type meshes. Appl. Math. 51(1), 63–72 (2006). https://doi.org/10.1007/s10492-006-0005-y
Roos, H.G., Linß, T.: Gradient recovery for singularly perturbed boundary value problems. I. One-dimensional convection-diffusion, pp. 163–178 (2001). https://doi.org/10.1007/s006070170033. Archives for scientific computing. Numerical methods for transport-dominated and related problems (Magdeburg, 1999)
Roos, H.G., Linß, T.: Gradient recovery for singularly perturbed boundary value problems. II. Two-dimensional convection-diffusion. Math. Models Methods Appl. Sci. 11 (7), 1169–1179 (2001). https://doi.org/10.1142/S0218202501001288
Schlichting, H., Gersten, K.: Boundary-Layer Theory, 9th edn. Springer, Berlin (2017). https://doi.org/10.1007/978-3-662-52919-5
Stynes, M., O’Riordan, E.: A uniformly convergent Galerkin method on a Shishkin mesh for a convection-diffusion problem. J. Math. Anal. Appl. 214(1), 36–54 (1997)
Stynes, M., Tobiska, L.: The SDFEM for a convection-diffusion problem with a boundary layer: optimal error analysis and enhancement of accuracy. SIAM J. Numer. Anal. 41(5), 1620–1642 (2003). https://doi.org/10.1137/S0036142902404728
Tobiska, L.: Analysis of a new stabilized higher order finite element method for advection-diffusion equations. Comput. Methods Appl. Mech. Engrg. 196(1-3), 538–550 (2006). https://doi.org/10.1016/j.cma.2006.05.009
Yan, N.: Superconvergence Analysis and a Posteriori Error Estimation in Finite Element Methods. Science Press, Beijing (2008)
Zhang, J., Liu, X.: Supercloseness of the SDFEM on Shishkin triangular meshes for problems with exponential layers. Adv. Comput. Math. 43 (4), 759–775 (2017). https://doi.org/10.1007/s10444-016-9505-9
Zhang, J., Liu, X.: Superconvergence of finite element method for singularly perturbed convection-diffusion equations in 1D. Appl. Math. Lett. 98, 278–283 (2019). https://doi.org/10.1016/j.aml.2019.06.018
Zhang, J., Liu, X.: Optimal order of uniform convergence for finite element method on Bakhvalov-type meshes. J. Sci. Comput. 85(1), 2 (2020). https://doi.org/10.1007/s10915-020-01312-y
Zhang, J., Liu, X.: Supercloseness of linear finite element method on Bakhvalov-type me shes for singularly perturbed convection-diffusion equation in 1D. Appl. Math. Lett. 111(106), 624 (2021). https://doi.org/10.1016/j.aml.2020.106624
Zhang, J., Liu, X.: Uniform convergence of finite element methods on Bakhvalov-type meshes in the case of \(N^{-1}\leqslant {\varepsilon }\). Appl. Numer. Math. 165, 519–526 (2021). https://doi.org/10.1016/j.apnum.2021.03.013
Zhang, J., Lv, Y.: High-order finite element method on a Bakhvalov-type mesh for a singularly perturbed convection-diffusion problem with two parameters. Appl. Math. Comput. 397, 125, 953 10 (2021). https://doi.org/10.1016/j.amc.2021.125953
Zhang, Z.: Finite element superconvergence on Shishkin mesh for 2-D convection-diffusion problems. Math. Comp. 72(243), 1147–1177 (2003). https://doi.org/10.1090/S0025-5718-03-01486-8
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This research is supported by the National Natural Science Foundation of China (11771257), Shandong Provincial Natural Science Foundation, China (ZR2021MA004).
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Zhang, J., Liu, X. Supercloseness and postprocessing for linear finite element method on Bakhvalov-type meshes. Numer Algor 92, 1553–1570 (2023). https://doi.org/10.1007/s11075-022-01353-4
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DOI: https://doi.org/10.1007/s11075-022-01353-4
Keywords
- Singular perturbation
- Convection–diffusion equation
- Finite element method
- Bakhvalov-type mesh
- Supercloseness