Polymeric materials are widely used in buildings and construction
applications and there is considerable interest in reducing their
fire hazard. The combustion of solid polymers is a complicated
process involving physical phenomena that are only partially understood.
Simple mathematical models are being developed in order to gain an insight
into the combustion characteristics of such materials.
- The development of mathematical models for experimental methods
that are commonly used to investigate flammability; in particular,
thermal analysis,
radiative ignition tests (specifically the cone calorimeter),
the
limiting oxygen index test and the extinction oxygen index test.
- The development of conceptually simple models using accepted
fire-engineering approximations, such as thermal pyrolysis and
critical mass flux models;
- The development of more complicated models,
involving the coupling of gas-phase and solid-phase processes, to
investigate under what conditions the approximations mentioned above
are valid.
- Investigating the effect that different classes of additive have in
different tests.
- The critical assembly problem:
if a material that has been exposed to a hot environment
is moved to a cooler environment will it ignite? This work
covers a number of fire hazard situations of wider
applicability, e.g. spontaneous combustion of bagasse
(sugar-cane residue), coal, textile materials etc.
- Given a material, what kind of
additive optimises performance for a given fire engineering test?
The areas of interest described above are for test-methods which
are `spatially uniform' in the sense that the source term is
applied uniformally across one side of the test-sample. Test
methods involving non-uniform source terms are also common, e.g.
tests employing wooden cribs as the ignition source. Models
for such experiments involve non-local reaction-diffusion
equations. The mathematical behaviour of such systems has been
little investigated. One of my long-term research goals is
to investigate such models.
- The use critical mass flux models to
systematically investigate the combustion characteristics of
polymers and polymer-additive systems.
- Offered an explanation of ``anomalous'' experimental data on the
time-to-ignition for polymer systems retarded with inert/heat-sink
additives.
- The development and analysis of a dynamical systems model for
polymer combustion in the cone calorimeter. I showed that
bifurcation theory provides the tools to establish generic
types of burning behaviour and to understand the
transitions between them, e.g. the change between
sustaining and non-sustaining combustion. In turn this offers
a basis for a systematic investigation into which types of
additive optimise the retardancy of different classes of polymer.
- Bifurcation analysis:
part I,
part II
- Investigation into the effect of flame emissivity on
burning behaviour.
(abstract)
- The limiting oxygen index test
- Using a dynamical systems framework I showed how the limiting
oxygen index can be identified as an appropriate bifurcation in
a model that had previously been investigated only by direct
integration. Showed how this critical value related to
different types of burning behaviour: marginally-stable
materials, self-extinguishing polymers and
intrinsically non-flammable.
(abstract)
- The previous model was extended to include two
common fire retardant mechanisms: non-competitive
char-formation and dilution by an inert filler.
The types of material that are best retarded by each
mechanism were identified.
(abstract)
M.I. Nelson, J. Brindley, and A.C. McIntosh.
A Mathematical Model of Ignition in the Cone Calorimeter.
Combustion Science and Technology,
104:35-54, 1995.
M.I. Nelson and J. Brindley.
Modelling Char-Formation in Isothermal and
Non-Isothermal Thermogravimetric Experiments.
Thermochimica Acta,
258:175-188, July 1995.
M.I. Nelson, J. Brindley, and A.C. McIntosh.
The Dependence of Critical Heat Flux on
Fuel and Additive Properties: A Critical Mass Flux Model.
Fire Safety Journal, 24(2):107-130, 1995.
M.I. Nelson, J. Brindley, and A.C. McIntosh.
Ignition Properties of Thermally Thin Materials
in the Cone Calorimeter: A Critical Mass Flux Model.
Combustion Science and Technology,
113-114:221-241, 1996.
M.I. Nelson, J. Brindley, and A.C. McIntosh.
Polymer Ignition.
Mathematical and Computer Modelling,
24(8):39-46, October 1996.
M.I. Nelson, J. Brindley, and A.C. McIntosh.
Ignition Properties of Thermally Thin
Thermoplastics - The Effectiveness of
Inert Additives in Reducing Flammability.
Polymer Degradation and Stability,
54(2-3):255-267, 1996.
M.I. Nelson, J. Brindley, and A.C. McIntosh.
The Effect of Heat Sink Additives on the
Ignition and Heat Release Properties of Thermally Thin Thermoplastics.
Fire Safety Journal,
28(1): 67-94, February 1997.
M.I. Nelson.
Ignition Mechanisms of Thermally Thin Thermoplastics
in the Cone Calorimeter.
Proceedings of the Royal
Society of London A, 454(1971):789-814,
March 1998.
E. Balakrishnan, M.I. Nelson, and G.C. Wake.
Radiative Ignition of Combustible Materials I.
Polymeric Materials Undergoing Non-Flaming Thermal Degradation -
The Critical Storage Problem.
Mathematical and Computer Modelling,
30(11-12):177-195, December 1999.
M.I. Nelson and J. Brindley.
Polymer Combustion: Effects of Flame Emissivity.
Philosophical Transactions of the Royal Society
of London Series A,
357:3655-3673, December 1999.
M.I. Nelson.
A dynamical systems model of the limiting oxygen index test.
II Retardancy due to char-formation and addition of inert fillers.
Combustion Theory and Modelling,
5(1): 59-83, March 2001.
M.I. Nelson, H.S. Sidhu, R.O. Weber, and G.N. Mercer.
A dynamical systems model of the limiting oxygen index test.
ANZIAM Journal,
43(1): 105-117, 2001.
J.E.J. Staggs and M.I. Nelson.
A critical mass flux model for the flammability of
thermoplastics.
Combustion Theory and Modelling, 5(3),
399-427, September 2001.
M.I. Nelson.
Thermally thin materials with enhanced fire-resistant
properties: A dynamical systems model.
Combustion Science and Technology,
167: 82-112, 2001.
M.I. Nelson, J. Brindley and A.C. McIntosh.
Ignition properties of thermally thin plastics: The effectiveness
of non-competitive char formation in reducing flammability.
Journal of Applied Mathematics and Decision Sciences,
6(3): 155-181, 2002.
Letters to the editor
M.I. Nelson, J. Brindley, and A.C. McIntosh.
Letter to the Editor: Response. Fire Safety Journal,
25(4): 357-360, November 1996.
Refereed conference proceedings
M.I. Nelson.
A Dynamical Systems Model of Autoignition in the
Cone Calorimeter.
In Fire Safety Science: Proceedings of the Fifth
International Symposium, pages 547-558.
International Association for Fire Safety Science,
1997. ISBN 4-9900625-5-5.
N. Waterhouse, H.S. Sidhu and M.I. Nelson.
Polymer combustion: The critical mass flux model. In
M. Pemberton, I. Turner, and P. Jacobs, editors, EMAC 2002
Proceedings, pages 231--236. The Institution of Engineers,
Australia, 2002. ISSN 1447-378X.
Unrefereed conference proceedings
M.I. Nelson.
The Autoignition of Thermoplastics in the Cone
Calorimeter: A Dynamical Systems Model. In
Proceedings of the 16th International
Colloquium on the Dynamics of Explosions and Reactive Systems,
pages 494-497. Wydawnictwo,, Akapit'' (Kraków, Poland),
1997. ISBN 83-7108-028-X.
Short articles on polymer combustion
I've written a series of
short articles. Each of these provide a short
overview of a particular topic that I've investigated in my research.
Several of them deal with polymer combustion.
<< Return to my list of research
interests.
<< Return to my start page.
Page Created: 18th April 2002.
Last Updated: 13th February 2004.