New tools for facilitating the integration of models into

teachingDavid F. Boutt

Umass-Amherst

Overview

• Many aspects of the Geosciences now use physically-based models for research

• Incorporating these into classes is often problematic

• Students could benefit from early exposure to these techniques

• New tools and faster computers offers an oppurtunity for educators

The Past

021

12

2

22

2

=∂∂

−∂∂

−+⎟⎟

⎠

⎞⎜⎜⎝

⎛

∂∂

+−∂∂

+∂∂

rp

rG

zu

ru

ru

rru

G rrrr αεν

021

12

2

22

2

=∂∂

−∂∂

−+⎟⎟

⎠

⎞⎜⎜⎝

⎛

∂∂

+∂∂

+∂∂

zp

zG

zu

ru

rru

G zzz αεν

t

pS

tz

p

r

p

rr

pkr ∂

∂=

∂∂

−⎟⎟⎠

⎞⎜⎜⎝

⎛

∂∂

+∂∂

+∂∂

εεα

μ 2

22 1

( ) ⎟⎟⎠

⎞⎜⎜⎝

⎛+

+= β

λρ n

GgSs w 23

3

( )( )ν+= 12GE

( )( )[ ]νννλ

+−=

121

E

The Present - Modeling Tools

• A number of GUI-based flexible modeling environments are available

• Real time simulation and visualization

• Useful for Lecture and Laboratory

• Two examples– COMSOL Multiphysics– Topodrive/particle flow

COMSOL Multiphysics

• A powerful generalized finite-element PDE solver with visualization

• Specific Earth Science Modules• Ideal for exploring coupled processes

– Fluid flow and deformation– Fluid flow and transport

• Good for setting up a problem and allowing students to perform sensitivity analysis

QuickTime™ and a decompressor

are needed to see this picture.

Topodrive/ParticleFlow

• 2D Steady state groundwater flow with particle transport– Developed by Paul Hsieh, USGS– Java-based, web app

• http://water.usgs.gov/nrp/gwsoftware/tdpf/tdpf.html

• Example use …

210 m

100 m

Normal stress on the system and the fractures.

Permeability of fractures under lithostatic stress conditions.

Hydraulic head where the permeability of fractures is constant.

Hydraulic head where the permeability of fractures is function of stress

Finite Element Model

A mesh is applied to the 2D model space

Plane Strain

Darcian Flow

Recharge

No Flow

Hydraulic Head

Gravitational Stress

Fixed Boundary

Fracture is an internal boundary

Displacement allowed

Permeable Fracture

The Future

• Student-driven real time modeling environments?

• 3D visualization?

Rest Stop

Hydra

ulic

Head (

m)

Rest Stop - Simulated