Numerical Tracer Experience
The MNI2 Project
Development and utilization of simulation tools for chemical engineering
The goals
1. Implement and simulate a numerical tracer test
through a porous media
2. Analyze the Residence Time Distribution (RTD) through
a porous media
Specific goals
1. Implement and simulate a numerical tracer test through a sand
column
a) Implement and simulate the water flow process by solving Richards
equation
b) Check the mass balance equation for water flow process
c) Display and comment the hydrodynamic functions at different times
until T = 1 day
d) At which time TS the column reached the steady state conditions ?
e) Implement and simulate the convection-dispersion equation by
considering steady state conditions for water flow process and
introducing a tracer as a conservative substance during TSf) Display and comment the outlet concentration of the tracer
Specific goals
1. Implement and simulate a numerical tracer test through a
sand column
2. Analyze the Residence Time Distribution (RTD) through the
porous media
a) Check the mass balance equation for convection-dispersion
process
b) Calculate and comment the RTD parameters for different
Neumann conditions: q0, 2q0, 3q0.
Governing equation for water flow process through
variably saturated porous media
Water input
Filter
Sand
column L

c
m
z = 0 cm
z = -L cm
z
ℎ ℎ = ℎ ℎ − 1

ℎ , = 0 = ℎ = 0, = = −, = ℎ = −,
q0 = −0.0001
h0 = −1000
Ksat = 0.0363 cm/s
α = 0.0472 cm-1
n = 1.48
θsat = 0.43
θres = 0.08
Governing equation for convection dispersion
process through variably saturated porous media
∙ + ∙ − =0 , = 0 = 0 = 0, < ≤ = = 0, < #$% > = 0 = − = 0
θ and q are respectively volumetric water content and
Darcian flux from water flow process
C0 = 1 '/
D = 0.004 cm2/s
t1 = 600s