Page 28 - Process Modelling and Simulation With Finite Element Methods

Introduction to FEMUB 15

you are not already a FEMLAB user, I would recommend requesting a
demonstration license for both FEMLAB and MATLAB. Mathworks [3] and
COMSOL [4] will provide one month trial licenses for both products free of
charge, with the software downloadable or available from CD-ROM shipped to
you by request. The Users’ Guide for FEMLAB is very good, and you might
want to read it after this Introduction and before Chapter One. I read all the
documentation that comes with FEMLAB cover to cover before designing and
delivering my first intensive module on chenlical engineering modeling with
FEMLAB [5] and highly recommend it. Nevertheless, I felt there was something
missing in the FEMLAB references, even though the Model Library and
Chemical Engineering Module references have a wealth of fascinating case
studies. I think it is the perspective of an expert user that is missing, but forgive
my hubris in thinking it is my perspective!
By now, you must be thinking that this book is a thinly veiled sales pitch for
FEMLABMATLAB. I would be dishonest if I did not make my preference for
modeling with FEMLABNATLAB clear at the outset of this book. There are
many packages for modeling available on the market, but FEMLAB is the first I
have seen for general purpose modeling that is equation based in generating the
PDE engine. Equations are the language of mathematical modeling and
mathematical physics, and FEMLAB aims to speak the language of its target
user community. So this book represents my personal odyssey in learning how
to adapt FEMLAB to modeling of chemical engineering processes, especially
but not exclusively PDE based. In the next section, I give a synopsis of the
themes treated in each chapter. As an experienced programmer with nearly two
decades of computational modeling and FEM experience, I could not have
achieved these results in the six months spent writing this book by any other
package in my arsenal, nor even by adapting research codes written by myself
and other expert numerical analysts with which I am proficient. This is also the
last endorsement for FEMLAB you will read in a book which only rarely makes
use of other tools. Some readers might notice Mathematica, MATLAB and
gnuplot graphics.
On the negative side, FEMLAB users are wont to complain that many
interesting post-processing manipulations require MATLAB programming and
exporting of results to the MATLAB workspace, the FEMLAB graphics are
“quaint” and the FEMLAB error messages are obtuse and cryptic. Ferreting out
errors in syntax is more difficult than with CFORTRAN compilers, although
MATLAB m-file scripts are generally more informative when they crash about
the nature of the problem than the same m-file run in the GUI. In part this comes
from the ability to interrogate the variables in the MATLAB workspace much as
one uses a debugger to tease out post-crash information from C. Perhaps a
future advance in FEMLAB will include access to the FEMLAB workspace.
Modelling or conceptual errors, however, are notoriously difficult to identify.