Hn. Cofer et Ma. Stadtherr, RELIABILITY OF ITERATIVE LINEAR-EQUATION SOLVERS IN CHEMICAL PROCESS SIMULATION, Computers & chemical engineering, 20(9), 1996, pp. 1123-1132
For large-scale problems, it may be attractive to use iterative method
s to solve the large, sparse, linear systems that arise in the equatio
n-based approach to process simulation. This is because, as problem si
zes grow, direct methods become extremely expensive in terms of both c
omputation time and storage requirements. Iterative methods, however,
may not be reliable for the indefinite and highly unsymmetric matrices
encountered in a diverse multi-unit flowsheeting problem. An extensiv
e computational study of the reliability of iterative linear solvers o
n such problems is presented here. Nine different iterative linear sol
vers are considered, in connection with incomplete factorization preco
nditioning. These are applied to a set of nine test problems. Results
indicate that the ordering of rows and columns in the matrices is a cr
ucial factor in determining the success with which iterative methods c
an be employed. Results also indicate that in general these multi-unit
flowsheeting matrices are difficult to solve by iterative methods, an
d that, though there is certainly potential in the use of iterative me
thods, to realize this potential will require improvements in the reor
dering and/or preconditioning schemes used. (C) 1996 Elsevier Science
Ltd