Environmental Engineering Reference
In-Depth Information
concentration [-]
1
0.9
0.8
0.7
0.6
0.5
Pe = -10
Pe = -1
Pe = -.1
Pe = 0
Pe = .1
Pe = 1
Pe = 10
0.4
0.3
0.2
0.1
0
0
0.2
0.4
0.6
0.8
1
distance [-]
Fig. 9.4 The steady-state solution of the advection-diffusion equation in dimensionless form in
dependence of the dimensionless P´clet number
results for the pure diffusion situation, is not plotted as it corresponds with the main
diagonal of the coordinate system. Clearly, the figure is symmetric with respect to
the diagonal.
The figure is obtained by the following command sequence and some post-
processing in the figure editor on the graphs' appearance (introduction of markers
and colors):
Pe = [-10,-1,-.1,0,.1,1,10];
x = [0:0.025:1];
figure; hold on;
for
i = 1:size(Pe,2)
plot (x,(1-exp(Pe(i).*x))./(1-exp(Pe(i).*ones(1,size(x,2)))));
end
legend ('Pe=-10','Pe=-1','Pe=-.1','Pe=0','Pe=.1','Pe=1','Pe=10');
The complete code is included in the accompanying software under the name
'sttransanal.m'
For aquatic sediments the fluid velocity in the pores decreases with depth. Near
the bottom the velocity is smaller, because the fluid obeys an additional moment
