6.2. Upstream Weighted Methods
171
k
",_=0.2
k "'_=0.47
--~---v
-----"~--v
j--~------""j
~=M
~=~
.--------~j
"'j=0.06
"';= 0.47
FIGURE 6.8. Weighting coefficients for two types of triangular elements.
FIGURE 6.9. Comparison between the c
analytic and the numerical solutions ofthe lOo-.:...o-<>-C>-O-o()-(l-'I'\"
upstream weighted MCBM. (1) Analytic
solution; (2) MCBM (A. = 0.0014).
FIGURE 6.10. Effects on the solution with
different values of A.. (1) Analytic solution;
(2) MCBM (A. = 0.0012); (3) MCBM (A. =
0.0018).
20
C
101--""""""1:'=6::10:-"1"
4
1 - -
3-0-,=SOd
Pe= 100
80 x
tion where the Peclet number is large, and decrease at a location where the
Peclet number is small. This property allows the method to be applied to
solve the advection dominated problems in unsteady flow fields.
Oscillations of numerical solutions may occur in practical problems if the
concentration fronts are steep or the pollution sources change rapidly with
time, even though the velocity of groundwater is low. Therefore, eliminating
oscillations of numerical solutions is important both in theory and in practice.