this presentation discusses the use of computational fluid dynamics and mathematical modeling to...
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This presentation discusses the use of computational fluid dynamics and mathematical modeling to optimize groundwater remediation. We use simplified two dimensional models first and Fluent (a well-know fluid flow simulator) to later obtain three-dimensional flow through an aquifer with varying contamination profiles and pumping strategies.
Groundwater Remediation*
University of Oklahoma – Chemical EngineeringTaren Blue, Laura Place,** Miguel Bagajewicz
*This work was done as part of the capstone Chemical Engineering class at the University of Oklahoma
**Capstone Undergraduate students
1. Analytical model2. Euler approximation3. Initial fluid flow model4. Refined fluid flow
model
Analysis Methods
Abstract
Drawing Geometry - Gambit
Aquifer Characteristics•Porosity of 25%
•Dimensions: 40×10×20•Unit length in meters•Volume = 8000 m3
•Desired Concentration = 3×10-7 kg/L
•Basis - Newalla OK site
Nonuniform Concentration Profiles
Plume Profile 1
Plume Profile 2
Plume Profile 3
Fluid Flow SimulationFluid flow simulations
were run in Fluent, a computational fluid dynamics software, and flow profiles were used to find concentration profiles.
Initial Trials:•Contamination plume was assumed to have uniform initial concentration•Well location constant•Wells pump in through side of aquiferSecondary trials:• Nonuniform initial concentration profiles •Pumping locations varied with time•More realistic well placement- wells enter through top of aquifer.
Advantage of Simulation Method
Many current models only involve two-dimensional analysis of the contamination profile. Fluid flow simulations allow for three dimensional modeling using 3D flow patterns of water in porous media.
Imaginary Planes
AcknowledgementsLinden Heflin Peter
LohateeraparpRoman Voronov
Imaginary planes are drawn and named individually in Fluent in order to find the mass flux through the planes.
Initial Fluid Flow Analysis
The geometries used are shown. Examples of path lines are displayed for two different well configurations. The path lines are colored by velocity. Blue faces represent inlets. Red faces
represent outlets.
kg/L
kg/L
kg/L
kg/L
0.000200
0.000150
0.000025
0.000100
A “generic” geometry is drawn in Gambit and imported into Fluent. Faces at the bottom of the pipes are turned “on” and “off” by being designated a mass flow inlet, outflow, or wall.
Pumping Strategies – Changing Well Configuration with Time
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
a5 b5 c5 d5
a6 b6 c6 d6
a7 b7 c7 d7
Strategy for Plume Profile 1
Jeffrey Harwell Benjamin Shiau Rufei Lu
Strategy for Plume Profile 2
Strategy for Plume Profile 3
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
a5 b5 c5 d5
a6 b6 c6 d6
a7 b7 c7 d7
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
a5 b5 c5 d5
a6 b6 c6 d6
a7 b7 c7 d7
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
a5 b5 c5 d5
a6 b6 c6 d6
a7 b7 c7 d7
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
a5 b5 c5 d5
a6 b6 c6 d6
a7 b7 c7 d7
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
a5 b5 c5 d5
a6 b6 c6 d6
a7 b7 c7 d7
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
a5 b5 c5 d5
a6 b6 c6 d6
a7 b7 c7 d7
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
a5 b5 c5 d5
a6 b6 c6 d6
a7 b7 c7 d7
a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 b4 c4 d4
a5 b5 c5 d5
a6 b6 c6 d6
a7 b7 c7 d7
Blue faces represent mass flow inlets. Red
faces represent outflows. White faces
are “off.”
Flow Profiles – Path Lines Colored by Velocity
Step 1 Step 2 Step 3 Step 1 Step 2 Step 3
Step 1 Step 2 Step 3
Plume 1 Step 1 Plume 1 Step 2 Plume 1 Step 3
Plume 2 Step 1 Plume 2 Step 2 Plume 2 Step 3
Plume 3 Step 1 Plume 3 Step 2 Plume 3 Step 3
Concentration Changes Over Time
Conclusions
0 20 40 601.50000000000001E-05
2.50000000000001E-05
3.50000000000001E-05
0.0000450000000000001
0.0000550000000000001
0.0000650000000000001
0.0000750000000000001
0.0000850000000000001
0.0000950000000000001
0.000105
Concentration vs TimePlume 3
Configuration 1Configuration 2Configuration 3Change
Time (days)
Conta
min
ant
Conce
ntr
ati
on
(kg/L
)
0 10 20 30 40 50 601.50000000000001E-05
2.50000000000001E-05
3.50000000000001E-05
0.0000450000000000001
0.0000550000000000001
0.0000650000000000001
0.0000750000000000001
0.0000850000000000001
0.0000950000000000001
0.000105
Concentration vs TimePlume 2
Configuration 2Configuration 3ChangeConfiguration 1
Time (days)
Conta
min
ant
Conce
ntr
ati
on
(kg/L
)
t = 4 days
t = 20 days
t = 50 days
t = 4 days
t = 20 days
t = 50 days
0 20 40 601.50000000000001E-05
2.50000000000001E-05
3.50000000000001E-05
0.0000450000000000001
0.0000550000000000001
0.0000650000000000001
0.0000750000000000001
0.0000850000000000001
0.0000950000000000001
0.000105
Concentration vs TimePlume 1
Configuration 2Configuration 3ChangeConfiguration 1
Time (days)
Conta
min
ant
Conce
ntr
ati
on
(kg/L
)
t = 4 days
t = 20 days
t = 50 days
10-13-10-8 kg/L10-7-10-6 kg/L10-5-10-4 kg/L10-4-10-3 kg/L
Velocity Contours
Plume 3 Step 2 Plume 3 Step 3
•Computational fluid dynamics can be applied to simulate flow of liquid through a porous media for modeling the remediation of a contamination plume.•This model builds upon previous 2D modeling schemes by analyzing fluid flow in three dimensions.•Imaginary planes allow for accurate tracing of flow profiles.•This method can be used in the analysis of various contamination plumes with:
• Varying initial concentration• Varying shape
•Model allows for varying pumping position and pumping rate with time. This can cause more effective cleaning and could lead to lower energy costs.
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