Research
My original background is in Numerical Analysis of methods used
to compute approximate solutions of partial differential equations.
I have since become more motivated by industrial applications and
have developed a skill in mathematical modelling.
I have an ongoing interest in the development of numerical methods for
geometric motion (curvature motion and surface diffusion for example)
of curves in 2D and surfaces in 3D. These geometric problems are idealizations
of some Material Science models. They become more difficult to solve
numerically
when junctions are present in the curve (or surface) networks. Much of
my work in this area has been in an idealized setting, although some
recent models developed by Keith Promislow show that geometric
motion can also arise in models of the pore structure in fuel cell
membranes (or more generally, in functionalized polymer materials).
I have recently become interested in adaptive time and space
methods for phase field versions of these geometric models working
with Keith Promislow and others at Michigan State University.
Another problem that is of interest to me is the computational capturing of two
phase zones in porous media. There are underyling questions of how to
handle the degenerate parabolic features of such models numerically and
analytically. Interest in this problem has
also led to the development of some novel methods to compute a general
class of steady free boundary value problems.
I am still interested in some theoretical questions in Numerical Analysis
and have some recent results in the analysis of errors from
piecewise uniform grids used to approximate smooth solutions.
I have also found a particularly simple setting to describe
known results on the errors from a large class of projection
methods for incompressible flow.
I am considering writing a longer review on the subject of Asymptotic
Error Analysis, the technique used to obtain these results and many other
results from early in my career.
In the period 1998-2008, my main research activity was fuel
cell modelling. In general
terms, the work focussed on the development of computational
design tools for the fuel cell industry. We developed models
describing various aspects of unit cell operation (transport and
chemical processes) and investigated coupling effects of the
unit cells in stack operation. Corresponding computational models were
developed. This was a larger project done in collaboration
with the company, Ballard Power Systems, and the MITACS NCE.
I am still interested in fuel cell modelling although
I am also interested in pursuing other industrial
projects with local industries.
Slides from some of my latest talks are
listed at the bottom of the page.
Some recent preprints
Former Students
I celebrate the achievements of graduate students, post-doctoral fellows,
research associates, and undergraduate summer students I supervised.
It was a pleasure working with you, best of luck to you all!
- Sandra Barsky, currently a research scientist at
General Fusion.
- Lloyd Bridge.
- Atife Caglar,
now a faculty member at the University of Wisconsin - Green Bay.
- Paul Chang, now working at
On Time Systems.
- Roger Donaldson, now an Industrial Mathematics Consultant in Vancouver.
- Brieuc Gilles.
- Ana Granados.
- Natalia Kouzniak, now a senior lecturer at SFU Surrey.
- Margaret Liang.
- Ricardo Martins.
- Arian Novruzi,
now a faculty member at the University of Ottawa.
- Zhenguo Pan.
- Steve Ruuth, now
a faculty member at SFU.
- John Stockie, now a
faculty member at SFU.
- Siyavash Towfighi.
- Justin Tzou.
- Cheng Zhang.
Selected Publications
Some selected publications I'm proud of for various reasons:
- Wetton and Brooke, "One-way wave equations for
seismo acoustic propagation in elastic wave guides," J. Acoust. Soc.
Amer. 87, 624-632 (1990).
- Ascher, Ruuth, and Wetton, "Implicit-Explicit Methods for
Time-Dependent PDE's," SINUM 32, 797-823 (1995).
- Bronsard and Wetton, "A Numerical Method for Tracking Curve
Networks Moving with Mean Curvature Motion," JCP 120, 66-87 (1995).
- Wetton, "Error Analysis for Chorin's original fully discrete
projection method and regularizations in space and time", SINUM 34,
1683-1697 (1997).
- Stockie and Wetton, "Analysis of stiffness of the immersed boundary
method and implications for time-stepping schemes," JCP 154, 41-64 (1999).
- Berg, Promislow, St-Pierre, Stumper, Wetton, "Water Management in
PEM fuel cells," Journal of the Electrochemical Society
151, A341-A353 (2004).
- Donaldson and Wetton, "Solving Steady Interface
Problems Using Residual Velocities," IMA Journal of Applied Mathematics
71, 877-897 (2006).
- Chang, Kim, Promislow and Wetton, "Reduced Dimensional
Computational Models of Polymer Electrolyte Membrane Fuel Cell Stacks,"
JCP 223, 797-821 (2007).
- Bridge and Wetton, "A mixture formulation for numerical capturing of a
two-phase/vapour interface in a porous medium," JCP 225, 2043-2068 (2007).
- Promislow and Wetton, "PEM Fuel Cells: A Mathematical Overview"
(invited review article) SIAM Journal of Applied Mathematics 70, 369 (2009).
Some recent talks
-
IAM directorship interview open forum presentation, March 13, 2013.
-
A general framework for high accuracy solutions to energy gradient
flows from material science models
in the UBC SCAIM seminar, January, 2013; and previously
at the SIAM annual meeting
in Minneapolis July, 2012; at the FACM meeting in Newark,
May, 2012; the SFU CRC Seminar, September, 2011; and at the
BCAM (Spain) seminar, November 14, 2011.
-
Jobs in "Industry" PIMS PDF Job Forum, October, 2012.
- Asymptotic Error Analysis
University of Hawaii at Manoa Mathematics Department Seminar,
February 24, 2012.
- Workshop on fuel cell modelling, given at the Polytechnic University of
Catalunya, October, 2011. Hand written notes for the lectures:
part I,
part II,
part III.
Matlab code:
-
Two Phase Transport in Porous Media
at the CRM (Spain) CAMP seminar, October 19, 2011; also at the
BCAM (Spain) seminar, November 14, 2011.
- Asymptotic Error Analysis, a series of four lectures given at the
Centre of Mathematical Modelling and Scientific Computing at
the National Chiao Tung University in Taiwan, December, 2010,
part I and
part II.
Some additional handwritten notes can be found
here.
- Approximating the
arctan function (notes for a blackboard talk) in the UBC
Undergraduate Mathematics Colloquium, September 2010. Also given at
the National Chiao Tung University in Taiwan, December, 2010.
- Asymptotic error
analysis of projection methods in the UBC SCAIM seminar,
September, 2010 and also
in the Scientific Computing session of the
CAIMS annual meeting, St. John's, July, 2010.
- Mathematical Modelling of
Hydrogen Fuel Cells at the CAIMS annual meeting, St. John's, July, 2010.
I also gave this talk at the SIAM Materials Meeting, Philadelphia, May, 2010.
A slightly different
version
was given at the PIMS Summer School on Computer Models and Geophysical Risk
Analysis in August, 2010.
- Asymptotic error
analysis on piecewise uniform grids in the Fluids Session of the
CAIMS annual meeting, St. John's, July, 2010.