Model of Melting and Dripping Thermoplastic Objects in Fire.
Model of Melting and Dripping Thermoplastic Objects in
Fire.
(1060 K)
Butler, K. M.
Fire and Materials 2009. 11th International Conference.
Conference Papers. Proceedings. Organised by
Interscience Communications Limited. January 26-28,
2009, San Francisco, CA, Interscience Communications
Limited, London, England, 341-352 pp, 2009.
Keywords:
thermoplastics; melting; dripping; equations;
experiments; flow rate; degradation; computation;
temperature; viscosity; heat flux; material properties
Abstract:
A model of the melting and dripping behavior of
thermoplastic materials in fire is being developed using
the Particle Finite Element Method (PFEM), which is
capable of tracking the large changes in shape inherent
to this problem in addition to solving the equations of
motion and energy. Experiments that approximate
two-dimensional flow situations provide a basis for
comparison for the model in its early stages of
development. Reasonable agreement with experiment has
been noted for the quasi-steady flow rate from an
upright rectangular object that is heated on one face.
The two-dimensional spread rate of the thermoplastic
melt that has dripped onto a surface beneath the object
has been measured experimentally for both horizontal and
slightly tilted catch plates. The model agrees within
10% to experimental results when further degradation of
the melt along the catch plate is taken into account.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899