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"NIST's Fire Dynamics Simulator (FDS) is a powerful tool for simulating the gas phase fire environment of scenarios involving realistic geometries. If the fire engineer is interested in simulating fire spread processes, FDS provides possible tools involving simulation of the decomposition of the condensed phase: gas burners and simplified pyrolysis models. Continuing to develop understanding of the capability and proper use of FDS related to fire spread will provide the practicing fire engineer with valuable information. In this work three simulations are conducted to evaluate FDS V.4's capabilities for predicting upward flame spread. The FDS predictions are compared with empirical correlations and experimental data for upward flame spread on a 5 m PMMA panel. A simplified flame spread model is also applied to assess the FDS simulation results. Capabilities and limitations of FDS V.4 for upward flame spread predictions are addressed, and recommendations for improvements of FDS and practical use of FDS for fire spread are presented."

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Tropical wildfires account for up to 93% of global burnt area and approximately 85% of the resulting carbon emissions, yet are significantly under-represented in existing fire models. These models are predominantly process-based, require a multitude of input datasets, parameters and calculations, and are difficult to reproduce or use independently from a dynamic global vegetation model (DGVM). The aim of this thesis is to develop empirical parameterisations of tropical fire occurrence and spread that represent an improvement in accuracy over existing models and that can be easily implemented both as standalone models or within a DGVM. These models are based on well-documented relationships from the literature. An index of potential fire is produced based on the observed peak of fire activity at intermediate levels of productivity and aridity. This can be converted into expected fire counts using a simple, observation-derived parameter map. Fire sizes have been shown to follow an approximately fractal distribution in a range of ecosystems, which is used to develop a new burnt area model. Replacing the fire count and burnt area calculations of existing fire models with these new parameterisations improves the spatial distribution of the resulting estimates, while giving temporally comparable predictions to the original models. The magnitude of the resulting burnt area estimates is also improved. The use of empirical fire modelling is therefore a viable alternative to current process-based methods, and makes practical use of theories that are well-documented in the literature. These models require few input variables and can be easily incorporated into a DGVM. However, further work to improve the temporal accuracy and dynamicity of these models would be beneficial, as would a method to link these models to parameterisations of combustion and trace gas emissions.

Fire spread between objects within a compartment is primarily due to the impingement of thermal radiation from the fire source. In order to estimate if or when a remote object from the fire will ignite, one must be able to quantify the radiative heat flux being received by the target. There are a variety of methods presented in the literature that attempt to calculate the thermal radiation to a target; each one based on assumptions about the fire. The performance of six of these methods, of varying complexity, is investigated in this research. This includes the common point source model, three different cylindrical models, a basic correlation and a planar model. In order to determine the performance of each method, the predictions made by the models were compared with actual measurements of radiant heat flux. This involved taking heat flux readings at numerous locations surrounding a propane gas burner. Different fire scenarios were represented by varying the burner geometry and heat release rate. Video recordings of the experiments were used to determine the mean flame heights using video image analysis software. After comparing the measured data with predictions made by the theoretical radiation methods, the point source model was found to be the best performing method on average. This was unexpected given the relative simplicity of the model in comparison to some of its counterparts. Additionally, the point source model proved to be the most robust of the six methods investigated, being least affected by the experimental variables. The Dayan and Tien method, one of the cylindrical models, was the second most accurate over the range of conditions tested in this work. Based on these findings, recommendations are made as to the most appropriate method for use in a radiation sub-model within an existing zone model software. The accuracy shown by the point source model, coupled with its ease of implementation, means that it should be suitable for such a use.

To build multi story buildings out of timber is of a common interest in the building sector. Timber as a building material has many profits, such as the low cost, the availability and the ability to recycle it, the low carbon footprint and the workability. Although, when it comes to fire protection of buildings with a timber based structure there are challenges regarding prevention of the spread of fire while timber surface is exposed to fire. There have been cases in which timber buildings have caught fire leading to severe fire spread and ruined buildings. One example concerns a student modulus accommodation in Luleå that caught fire in august 2013. The fire started on the fourth floor after which a vertical fire spread occurred in concealed spaces between the volume modules. According to the fire investigation lack of knowledge regarding performance of detailed building solutions has led to the poor fire performance of the building. This master thesis mainly consists of a model scale tests that is prepared and performed according to the standard EN 1363-1. The purpose of the test is to investigate the performance of various cavity barriers exposed to fire. The main objective is to examine which temperatures that can be expected at different positions at various cavity barriers when using model scale test as a test method. There are two main kinds of cavity barriers: barriers that are airtight and closed inside the voids of the construction; and ventilated barriers. The most common cavity barriers are the ones that are airtight and closed. The material can be solid wood, gypsum board or mineral wool. The installation areas for these cavity barriers are anywhere, besides where the concealed spaces shall be ventilated and in every joint that shall be sealed using sealant. The ventilated cavity barriers are mounted in concealed spaces where the ventilating function is provided. These concealed spaces are often situated in, for example, ventilated attics, facades and roofs. The purpose of the ventilated barriers is to maintain the air flow in the cavity during regular conditions but also to form a protecting barrier between fire compartments when exposed to fire. The model scale test includes test apparatuses such as thermocouples and a fire resistance furnace with plate thermometers and burners. In addition, a test rig consisting of test specimens and the products to be tested are essential.  In this report, two model scale tests have been performed and prepared according to EN 1363‑1. The test period endured for four hours and the thermocouples measured the temperatures during the whole time. During the first hour the test specimens were exposed to the standard ISO 834 fire curve by controlling the burners in the furnace. After one hour the burners were turned off and the specimens were no longer exposed to fire. The measurements of the temperatures continued during three more hours. After the first two of these three hours the furnace was opened to confer more oxygen in the purpose to record any changes in the temperatures. Results of the performed experiments have indicated parameters that affect the performance of the cavity barriers. The cavity surface itself has an influence to the fire spread. The number of barriers in the cavity and the material properties of the material that is used as the cavity barrier lead to the different protection by those cavity barriers. Some of the tested barriers were plastic covered, which had effect on the performance of the cavity barriers. The dimensions of the barriers, moreover the width and the thickness, are important parameters for the proper function of the barrier. The test results indicate that glowing combustion occurs in the cavity between various cavity barriers.  It can be seen that the temperature rises when the furnace is opened. This indicates the appearance of smouldering since the combustion increases when the amount of oxygen increases, which leads to a temperature rise. Furthermore, the appearance of smouldering (glowing combustion) can be indicated by the observation of the damages of the specimens after the test. The temperatures that may be expected at the unexposed side of the cavity barrier depend on the surface material of the cavity, dimensions, and the material of the cavity barriers. Smouldering is a consequence of the temperature rise in closed cavities between cavity barriers. The performed test endured for approximately four hours and this indicates that fires in cavities can stay for a long time. To ensure the performance of various cavity barriers and verification by a model scale test it is important to perform further experiment and analyses to investigate the effects of the various parameters. To ensure the effectiveness of the performance of the cavity barriers they should be tested in cavities with various widths and various heights. Further investigation of the risk for smouldering is needed with measuring the amount of oxygen and the pressure.

<p>In 2002 an amendment was added to the International Convention for the Safety of Life at Sea (SOLAS) which opened up for shipbuilders to replace steel with lightweight materials in the superstructures. However, SOLAS requires equal fire safety compared to ships with steel superstructures.</p><p> </p><p>LASS-c is a cross-organizational project with the aim to find a method to build cruise ships with part of the superstructure made in lightweight materials. As a part of the LASS-c project the purpose of this thesis has been to develop an application in Java (FISPAT). The tool has been designed to find fire sensitive areas in structures such as cruise vessels. A second aim with the thesis has been to evaluate the cruise ship Norwegian Gem with respect to fire sensitive areas.   </p><p> </p><p>In FISPAT the user can make a model of a structure. The model is built up by rooms, networks and devices. With the model, FISPAT can simulate fire spread and the effects on the networks included in the model. The user can then analyze the results to find fire sensitive parts.</p><p> </p><p>One of the main results in this thesis is the tool itself together with this report which also serves as a manual to FISPAT. An evaluation of Norwegian Gem was also made which points to some critical parts of the ship. One example is the main water supply pipe to the sprinklers which has no redundant systems and all sectioning valves are manually operated, hence it is vulnerable to faults. The electrical feed to the three pump units is also a vulnerable point on the vessel. The pumps have redundant electrical networks, but the wires are drawn on the same paths, making it possible to take out both systems with one fire.</p>

In 2002 an amendment was added to the International Convention for the Safety of Life at Sea (SOLAS) which opened up for shipbuilders to replace steel with lightweight materials in the superstructures. However, SOLAS requires equal fire safety compared to ships with steel superstructures.   LASS-c is a cross-organizational project with the aim to find a method to build cruise ships with part of the superstructure made in lightweight materials. As a part of the LASS-c project the purpose of this thesis has been to develop an application in Java (FISPAT). The tool has been designed to find fire sensitive areas in structures such as cruise vessels. A second aim with the thesis has been to evaluate the cruise ship Norwegian Gem with respect to fire sensitive areas.      In FISPAT the user can make a model of a structure. The model is built up by rooms, networks and devices. With the model, FISPAT can simulate fire spread and the effects on the networks included in the model. The user can then analyze the results to find fire sensitive parts.   One of the main results in this thesis is the tool itself together with this report which also serves as a manual to FISPAT. An evaluation of Norwegian Gem was also made which points to some critical parts of the ship. One example is the main water supply pipe to the sprinklers which has no redundant systems and all sectioning valves are manually operated, hence it is vulnerable to faults. The electrical feed to the three pump units is also a vulnerable point on the vessel. The pumps have redundant electrical networks, but the wires are drawn on the same paths, making it possible to take out both systems with one fire.

Shrub fuels are capable of extreme fire behaviour under conditions that are often moderate in other fuels. There is also a narrow range of conditions that determine fire success in these fuels, below which fires may ignite but hardly spread and above which they ignite and develop into fast moving and high intensity fires. This is due to the elevated dead fine fuels that dry rapidly and carry fire. Fire danger rating systems designed for forest and grassland fuels do not predict fire potential in shrub fuels very well. Fire management requires fire danger rating systems to provide accurate and timely information on fire potential for all important fuel types. Studies of fuel moisture, ignition and fire spread were carried out in the field in gorse (Ulex europaeus L.) shrub fuels to predict the moisture content of the elevated dead fuels and to define the conditions that govern fire development. The accuracy of the Fine Fuel Moisture Code (FFMC) of the Canadian Forest Fire Weather Index (FWI) System to predict moisture content of this layer was assessed. A bookkeeping method to predict moisture content was developed based on semi-physical models of equilibrium moisture content, fuel response time and the FFMC. The FFMC predicted moisture content poorly, because the FWI System is based on the litter layer of a mature conifer forest. The gorse elevated dead fuel layer is more aerated and dries faster than this conifer forest litter layer. The bookkeeping method was reliable and allowed adjustment of fuel response time based on weather conditions. Difficulties in modelling meteorological conditions under the gorse canopy limited its accuracy. Separate thresholds determined ignition and fire spread success, with both based on the elevated dead fuel moisture content. Options to improve the shrub fire danger rating system were presented based on these findings. The results are significant because they are based on data collected in the field under real conditions. Validation of these results and extension to other shrub fuels is required before the findings are used to change current models. However, the study has significantly advanced the knowledge of fire behaviour in shrub fuels and will contribute to safe and effective fire management in these fuels.

A challenge for fire researchers is obtaining data from those fires that are most dangerous and costly. While it is feasible to instrument test beds, test plots, and small prescribed burns for research, it is uncommon to successfully instrument an active wildland fire. With a focus on very specific facets of wildland fire, researchers have created many unique models utilizing matchsticks, cardboard, liquid fuel, excelsior, plywood, live fuels, dead fuels, and wood cribs of different packing densities. Such scale models, however, only serve as valid substitutes for the full-scale system when all functional relations of the scale model are made similar to corresponding relations of the original phenomena. The field of study of large wildland fires therefore was in need of a framework that researchers could use to relate the results from many previous experiments to full-scale wildland fires; this framework was developed during the research for this dissertation. This further work developing laws for instability scaling in wildland settings was founded on the established work in dynamic similitude of G.I. Taylor, H. C. Hottel, F. A. Williams, R. I. Emori, K. Saito and Y. Iguchi. Additionally, in this work, a new dynamic flame parameter was incorporated into the scaling laws for fires that had not previously been assessed and proved to provide additional, important insight into flame spread. The new dynamic parameter enabled improved St-Fr correlations and was established for a wide range of fire sizes and fuel types.