Comparison of Two-Level Preconditioners using Deflation Techniques applied to Flow Problems

Master thesis (2018)

Authors

J.Y.Y. Tjan Electrical Engineering, Mathematics and Computer Science

Contributors

Cornelis Vuik (supervisor 1)
G.B. Diaz Cortes (supervisor 1)
Damiano Pasetto (supervisor 2)
H.M. Schuttelaars (supervisor 2)
Faculty
Electrical Engineering, Mathematics and Computer Science
Copyright: © 2018 Jenny Tjan
Deflation
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Published Date

30-08-2018

Language

English

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Faculty

Electrical Engineering, Mathematics and Computer Science

Abstract

We investigate the simulation of one-phase and two-phase flow through heterogeneous porous media.The derived matrix, resulting from reservoir simulation of groundwater flow problems, can result in a large and ill-conditioned system, i.e. the matrix has a high condition number, and the modelling takes large computation time. In this thesis report, the Two-Level Preconditioned Conjugate Gradient method with deflation techniques will be considered. Recently, new Two-Level preconditioners are constructed using the AMG approach. In this research we compare this approach with the standard Two-Level preconditioners. We found that the performance of these methods can be improved by using a special starting vector and previous time-step as initial condition. From the results we see that the performance and the memory storage of the methods are similar. However, the cheapest methods per iteration resulted DEF1, DEF2, R-BNN2, and ROM.

Files

Final_Thesis.pdf
(.pdf | 2.01 Mb)