Center of gravity analytic solver platform

In particular for very ill-conditioned matrices, sophisticated preconditioner are necessary to obtain both acceptable convergence and accuracy of CG. The large size and the condition of many technical or physical applications in this area result in the need for efficient parallelization and preconditioning techniques of the CG method. [Central Institute for Applied Mathematics, Juelich (Germany)Д¬onjugate gradient ( CG) methods to solve sparse systems of linear equations play an important role in numerical methods for solving discretized partial differential equations. Parallel preconditioning techniques for sparse CG solversД®nergy Technology Data Exchange (ETDEWEB)Д«asermann, A. Sample problems are presented related to heat and fluid flow at Yucca Mountain and WIPP, environmental remediation by the Thermal Enhanced Vapor Extraction System, and geothermal resources Results from six test problems with up to 30,000 equations show that T2 CG1 (1) is significantly (and invariably) faster and requires far less memory than the MA28 direct solver, (2) it makes possible the solution of very large three-dimensional problems on PCs, and (3) that the BCGS solver is the fastest of the three in the tested problems. T2 CG1 includes three different solvers: a Bi-Conjugate Gradient (BCG) solver, a Bi-Conjugate Gradient Squared (BCGS) solver, and a Generalized Minimum Residual (GMRES) solver.

T2 CG1, a package of preconditioned conjugate gradient solvers, has been added to TOUGH2 to complement its direct solver and significantly increase the size of problems tractable on PCs. However, because of large storage requirements and accumulation of roundoff errors, the application of direct solution techniques is limited, depending on matrix bandwidth, to systems of a few hundred to at most a few thousand simultaneous equations. The simplest technique for solving such equations is by direct methods.

Most of the computational work in the numerical simulation of fluid and heat flows in permeable media arises in the solution of large systems of linear equations.

International Nuclear Information System (INIS) T2 CG1, a package of preconditioned conjugate gradient solvers for TOUGH2

Center of gravity analytic solver platform