clarke@utcsri.UUCP (10/30/87)
NUMERICAL ANALYSIS SEMINAR, Thursday, November 5, 3:30 pm, GB119
(GB = Galbraith Building, 35 St. George Street)
Professor Peter A. Forsyth
University of Waterloo
"Adaptive Implicit Methods for Multiphase Flow
in a Porous Medium"
Modelling of multiphase flow in a porous medium has applications in
petroleum reservoir simulation, contamination of groundwater due to leakage
form toxic waste dumps, and geothermal energy extraction.
These systems are described by a set of coupled, non-linear hyperbolic-
parabolic partial differential equations. Stability requirements necessi-
tate some form of implicit treatment. The adaptive implicit technique
attempts to minimize computational work by using different degrees of
implicitness on a cell by cell basis. The degree of implicitness is
dynamic, and can change during the course of the simulation.
This talk will discuss some of the criteria for switching cells from expli-
cit to implicit and vice versa. Since Newton iteration is used to solve
the non-linear algebraic equations, a large sparse linear system must be
solved. An incomplete LU factorization preconditioning is used to solve
this system. Results from some example problems in reservoir simulation
and groundwater contamination will also be given.
--
Jim Clarke -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4
(416) 978-4058
{allegra,cornell,decvax,linus,utzoo}!utcsri!clarke