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.