Publication Date:
2023-06-12
Description:
Two efficient and scalable numerical solution methods will be compared using exact Jacobians to solve the fully coupled Newton systems arising during fully implicit discretization of the equations for two-phase flow in porous media. These methods use algebraic multigrid (AMG) to solve the linear systems in every Newton step. The algebraic multigrid methods rely on (i) a Schur Complement Reduction (SCR-AMG) and (ii) a Constrained Pressure Residual method (CPR-AMG) to decouple elliptic and hyperbolic contributions. Both methods employ automatic differentiation (AD) to calculate exact Jacobians and are compared with finite difference (FD) approximations of the Jacobian. The superiority of AD is shown by several numerical test cases from the field of CO2 geo-sequestration comprising two- and three-dimensional examples. A weak scaling test on JUQUEEN, a BlueGene/Q supercomputer, demonstrates the efficiency and scalability of both methods. To achieve maximum comparability and reproducibility, the Portable Extensible Toolkit for Scientific Computation (PETSc) is used as framework for the comparison of all solvers.
Description:
Horizon 2020
https://doi.org/10.13039/501100007601
Description:
Horizon 2020
https://doi.org/10.13039/501100007601
Keywords:
ddc:550.2
;
Algebraic multigrid (AMG)
;
Schur complement reduction (SCR-AMG)
;
Constrained pressure residual (CPR-AMG)
;
Multiphase flow in porous media
;
Automatic differentiation (AD)
;
CO2 geo-sequestration
;
65F08
;
65M55
;
76T10
Language:
English
Type:
doc-type:article
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