Different decomposition models of varying complexity were developed to predict the heat and mass transfer through charring/reinforced materials that are undergoing decomposition. Models included a heat conduction based model, decomposition model neglecting internal pyrolysis gas convection, and decomposition model with internal convection. Experimental methods were developed to measure the decomposition kinetic parameters and thermal properties required for input into the different models. Model results compared well with experimental data. Agreement between the heat conduction model was further improved by modifying the heat of decomposition to account for the internal convection effects. A Pre-exponential factor (Hz) C Specific heat capacity (J/kg°C) E Activation energy (J/gmol) f Fraction of initial mass remaining (-) F Fraction of decomposed mass remaining (-) h Enthalpy (J/kg) h conv Convective heat transfer coefficient (W/m 2°C ) k Thermal conductivity (W/m°C) L Overall thickness of region being modeled (m) m Mass (kg) _ m g Mass flow pyrolysis gases through char (kg/s) _ m 00 g Mass flow rate per unit area of pyrolysis gases through char (kg/s m 2 ) M Kinetic rate expression function (-) n Order of reaction (-) q 00 Heat flux (kW/m 2 ) Q Heat of Decomposition, negative is endothermic (kJ/kg) R Universal gas constant (8.314 J/gmol K) t Time (s) T Temperature (°C or K) V Volume (m 3 ) xDistance along the sample thickness from the heated surface (m)

The winds generated at 11:45 a.m. by 38 fires and at 12:OO p.

SUMMARYA one-dimensional, transient thermal degradation heat transfer model for the response of composite materials when exposed to fire is presented. The model can handle layers of different materials. Material properties are functions of temperature. The reaction can be specified using Arrhenius-type parameters or by inputting a density-temperature relationship determined by any experimental technique such as thermogravimetric analysis. The model is validated against the experimental data presented in Boyer's 1984 dissertation. Overall, the model provides excellent agreement with the experimental data. It is shown that very little difference is found between results arrived at by Arrhenius kinetics and results obtained by specifying the easier to measure density-temperature relationship. From this it is concluded that this technique is a viable alternative to Arrhenius-type models.

A series of full-scale fire suppression tests was conducted at the San Pedro de Anes test tunnel facility near Gı´jon, Asturias, Spain in February 2006. The fuel was wooden pallets or a mixed load of wood and high density polyethylene pallets. Fire protection was provided by water mist systems in different configurations. Because of facility restrictions, some scenarios of great interest, such as a free burn fire, could not be investigated. However, in order to complement the experimental results, a number of computational fluid dynamics simulations were conducted on a 140 m section of the tunnel facility. The Fire Dynamics Simulator, version 4, was used for the numerical investigation. An algorithm was developed to allow the fire to spread along the top of a series of pallet loads in such a way that the measured heat release rate was reproduced. Verification and validation studies confirmed that the model predicted the measured ventilation speeds and peak temperatures. The agreement between the simulations and the field measurements was very good prior to activation of the water mist. Back-layering was modeled well. After activation of the mist, the simulations predicted a large drop in gas temperatures, and retreat of the back-layer, but under-predicted the thermal cooling by the water mist downstream of the fire. With the suppression system, high temperatures and heat fluxes were limited to the immediate vicinity of the burning pallets. The model was then used to simulate a free burn fire in the tunnel. The simulation demonstrated the catastrophic conditions created by an unsuppressed fire in a tunnel when compared against the thermally managed conditions under suppressed conditions.

SUMMARYThermal properties were measured on coupon size samples for use in predicting the temperature response and mass transfer during fires exposures. The thermal properties were determined up to temperatures of 800 • C through inverse heat transfer analysis on temperature response and mass loss data. Temperature response and mass loss data were determined using a high heat flux decomposition apparatus with controlled oxygen environment. Data included thermal conductivity, specific heat capacity, and density as a function of temperature as well as heat of decomposition and Arrhenius kinetic decomposition constants. Properties for inert materials (no decomposition) compared well with manufacturer reported values and values using other methods. Properties for two decomposing materials, woven glass vinyl ester composite and balsa wood, were measured and compared well with data from other methods.