Abstract
We propose a Nested BDDC for a class of saddle-point problems. The method solves for both flux and pressure variables. The fluxes are resolved in three-steps: the coarse solve is followed by subdomain solves, and last we look for a divergence-free flux correction and pressure variables using conjugate gradients with a Multilevel BDDC preconditioner. Because the coarse solve in the first step has the same structure as the original problem, we can use this procedure recursively and solve (a hierarchy of) coarse problems only approximately, utilizing the coarse problems known from the BDDC. The resulting algorithm thus first performs several upscaling steps, and then solves a hierarchy of problems that have the same structure but increase in size while sweeping down the levels, using the same components in the first and in the third step on each level, and also reusing the components from the higher levels. Because the coarsening can be quite aggressive, the number of levels can be kept small and the additional computational cost is significantly reduced due to the reuse of the components. We also provide the condition number bound and numerical experiments confirming the theory.
Similar content being viewed by others
References
Brenner, S.C., Sung, L.Y.: BDDC and FETI-DP without matrices or vectors. Comput. Methods Appl. Mech. Engrg. 196(8), 1429–1435 (2007)
Brezzi, F., Fortin, M.: Mixed and Hybrid Finite Element Methods. Springer-Verlag, New York-Berlin-Heidelberg (1991)
Cowsar, L.C., Mandel, J., Wheeler, M.F.: Balancing domain decomposition for mixed finite elements. Math. Comp. 64(211), 989–1015 (1995)
Cros, J.M.: A preconditioner for the Schur complement domain decomposition method. In: I. Herrera, D.E. Keyes, O.B. Widlund (eds.) Domain Decomposition Methods in Science and Engineering, pp. 373–380. National Autonomous University of Mexico (UNAM), México (2003). 14th International Conference on Domain Decomposition Methods, Cocoyoc, Mexico, January 6–12, (2002)
Dohrmann, C.R.: A preconditioner for substructuring based on constrained energy minimization. SIAM J. Sci. Comput. 25(1), 246–258 (2003)
Ewing, R.E., Wang, J.: Analysis of the Schwarz algorithm for mixed finite element methods. RAIRO Mathematical Modelling and Numerical Analysis 26(6), 739–756 (1992)
Farhat, C., Lesoinne, M., Le Tallec, P., Pierson, K., Rixen, D.: FETI-DP: a dual-primal unified FETI method. I. A faster alternative to the two-level FETI method. Internat. J. Numer. Methods Engrg. 50(7), 1523–1544 (2001)
Farhat, C., Lesoinne, M., Pierson, K.: A scalable dual-primal domain decomposition method. Numer. Linear Algebra Appl. 7, 687–714 (2000)
Farhat, C., Roux, F.X.: A method of finite element tearing and interconnecting and its parallel solution algorithm. Internat. J. Numer. Methods Engrg. 32, 1205–1227 (1991)
Fragakis, Y., Papadrakakis, M.: The mosaic of high performance domain decomposition methods for structural mechanics: Formulation, interrelation and numerical efficiency of primal and dual methods. Comput. Methods Appl. Mech. Engrg. 192, 3799–3830 (2003)
Glowinski, R., Wheeler, M.F.: Domain decomposition and mixed finite element methods for elliptic problems. In: Glowinski, R., Golub, G.H., Meurant, G.A., Périaux, J. (eds.) First International Symposium on Domain Decomposition Methods for Partial Differential Equations. SIAM, Philadelphia, PA (1988)
Klawonn, A., Rheinbach, O.: A hybrid approach to 3-level FETI. PAMM 8(1), 10,841–10,843 (2008). DOI:10.1002/pamm.200810841. 79th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM), Bremen (2008)
Klawonn, A., Rheinbach, O., Widlund, O.B.: An analysis of a FETI-DP algorithm on irregular subdomains in the plane. SIAM J. Numer. Anal. 46(5), 2484–2504 (2008)
Li, J., Widlund, O.B.: BDDC algorithms for incompressible Stokes equations. SIAM J. Numer. Anal. 44(6), 2432–2455 (2006)
Li, J., Widlund, O.B.: FETI-DP, BDDC, and block Cholesky methods. Internat. J. Numer. Methods Engrg. 66(2), 250–271 (2006)
Mandel, J.: Balancing domain decomposition. Comm. Numer. Methods Engrg. 9(3), 233–241 (1993)
Mandel, J., Dohrmann, C.R., Tezaur, R.: An algebraic theory for primal and dual substructuring methods by constraints. Appl. Numer. Math. 54(2), 167–193 (2005)
Mandel, J., Sousedík, B.: Adaptive selection of face coarse degrees of freedom in the BDDC and the FETI-DP iterative substructuring methods. Comput. Methods Appl. Mech. Engrg. 196(8), 1389–1399 (2007)
Mandel, J., Sousedík, B.: BDDC and FETI-DP under minimalist assumptions. Computing 81, 269–280 (2007)
Mandel, J., Sousedík, B., Dohrmann, C.R.: Multispace and multilevel BDDC. Computing 83(2–3), 55–85 (2008)
Mathew, T.P.: Schwarz alternating and iterative refinement methods for mixed formulations of elliptic problems, part I: Algorithms and numerical results. Numer. Math. 65(4), 445–468 (1993)
Pavarino, L.F., Widlund, O.B.: Balancing Neumann-Neumann methods for incompressible Stokes equations. Comm. Pure Appl. Math. 55(3), 302–335 (2002)
Šístek, J., Sousedík, B., Burda, P., Mandel, J., Novotný, J.: Application of the parallel BDDC preconditioner to the Stokes flow. Comput. & Fluids 46, 429–435 (2011)
Sousedík, B.: Comparison of some domain decomposition methods. Ph.D. thesis, Czech Technical University in Prague, Faculty of Civil Engineering, Department of Mathematics (2008). http://mat.fsv.cvut.cz/doktorandi/files/BSthesisCZ.pdf
Sousedík, B., Šístek, J., Mandel, J.: Adaptive-Multilevel BDDC and its parallel implementation. Computing (2013). doi:10.1007/s00607-013-0293-5
Sousedík, B., Mandel, J.: On Adaptive-Multilevel BDDC. In: Huang, Y., Kornhuber, R., Widlund, O., Xu, J. (eds.) Domain Decomposition Methods in Science and Engineering XIX, Lecture Notes in Computational Science and Engineering 78, Part 1, pp. 39–50. Springer-Verlag, (2011)
Toselli, A., Widlund, O.B.: Domain Decomposition Methods–Algorithms and Theory, Springer Series in Computational Mathematics, vol. 34. Springer-Verlag, Berlin (2005)
Tu, X.: A BDDC algorithm for mixed formulation of flow in porous media. Electron. Trans. Numer. Anal. 20, 164–179 (2005)
Tu, X.: BDDC domain decomposition algorithms: Methods with three levels and for flow in porous media. Ph.D. thesis, Department of Mathematics, New York University (2006). http://cs.nyu.edu/csweb/Research/TechReports/TR2005-879/TR2005-879.pdf
Tu, X.: A BDDC algorithm for flow in porous media with a hybrid finite element discretization. Electron. Trans. Numer. Anal. 26, 146–160 (2007)
Tu, X.: Three-level BDDC in three dimensions. SIAM J. Sci. Comput. 29(4), 1759–1780 (2007)
Tu, X.: Three-level BDDC in two dimensions. Internat. J. Numer. Methods Engrg. 69(1), 33–59 (2007)
Tu, X.: A three-level BDDC algorithm for a saddle point problem. Numerische Mathematik 119(1), 189–217 (2011)
Acknowledgments
I would like to thank Dr. Christopher Harder and Prof. Jan Mandel for many discussions over the paper, and the referees for useful comments and suggestions.
Author information
Authors and Affiliations
Corresponding author
Additional information
Part of the work has been completed while the author was a Research Assistant Professor at the Department of Mathematical and Statistical Sciences, University of Colorado Denver.
Supported in part by the National Science Foundation under grant DMS-0713876, and by the Grant Agency of the Czech Republic GAČR 106/08/0403. Support from DOE/ASCR is also gratefully acknowledged.