Zone Models are a widely used tool in fire protection engineering to predict how fires will develop in compartments. Zone models use entrainment algorithms for plumes in the open and the effect of enclosures on the entrainment is currently unclear. This work was a systematic study of six global parameters that effect flame height and the enclosure effect on fire plume entrainment.

"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."

"This thesis evaluates the effectiveness of BEHAVE: Fire Behavior Prediction and Fuel Modeling System in predicting fire behavior in the Northeastern pine-oak forest. This fuel complex is composed primarily of a litter and huckleberry shrub understory with a pitch pine and oak overstory. Measurements of fuel bed physical characteristics, weather and fire behavior are taken from a series of prescribed burn studies in Cape Cod National Seashore in Massachusetts. Site-specific fuel models are constructed which provide the necessary inputs for fire predictions. Observed spread rates and flame lengths are over-predicted by BEHAVE for burns conducted during the winter (dormant season) and under-predicted for burns conducted during the summer (growing season). Attempts to improve winter predictions are successful when the litter moisture is adjusted in order to account for the live wintergreen which increases the overall moisture content of the surface fuels. A sensitivity study is performed where each input parameter is varied over a reasonable interval in order to view its impact on predictions. The model’s high sensitivity to fuel bed depth and 1-hr surface-area-to-volume ratio appear to be the cause for fire prediction deviations during the winter, while the high live fuel moisture contents appear to overwhelm and suppress fire behavior predictions during the summer. It is concluded to overwhelm and suppress fire behavior predictions during the summer. It is concluded that BEHAVE’s representation of fuel complexes as a homogeneous fuel bed with constant properties does not take into account the unique features of the litter and shrub components. An alternative, simple model of fire spread is developed which treats each component as a separate fuel bed. The model is based on a measurement of the heat release rate which can be determined directly through the principle of oxygen consumption calorimetry. Future work using small- and large- scale testing apparatus will help determine the ignition process of the live shrubs and the effect of parameters such as moisture content on the burning characteristics of the fuels. "

The United States of America (US) has a long-standing history of fire management through the United States Forest Service. Despite this history of fire management, the US faces significant increases in fire potential across the 21st Century owing to future climate change and due to a legacy of past fuel management policies. Since the 1970s the US Forest Service (USFS) has operated a fire danger rating system, known as the National Fire Danger Rating System (NFDRS), which has aimed to portray, anticipate, and mitigate wildfires across the country. Fire danger ratings essentially aim to describe how dangerous a fire would be if it were to ignite and are used to inform not only the general public about wildfire risk but are also used by forest and fire managers to determine their actions in regards to fire suppression. The US Forest Service’s NFDRS currently produces 1-day forecasts of fire danger through the Wildland Fire Assessment System, and other state-focused outlets. The system quantifies common aspects of fire behaviour over wide spatial extents through a number of fire danger indices. These indices represent aspects of fire danger in terms of the likelihood of ignitions, rate of spread, potential heat release, and difficulty of control. Despite the NFDRS’s long-standing utility across the US, relatively few studies have sought to relate fire danger observations and forecasts to records of wildfire activity across its operational spatial extent. The majority of assessments of the NFDRS have been conducted at either single sites or on small spatial scales, despite it being a nation-wide system. This thesis analyses the NFDRS in respect to the occurrence of wildland fires and the final fire sizes they attain over an eight year period (2006-2013) through a number of analyses that; (i) examine the system’s ability to portray wildfire activity across the conterminous US; (ii) assess the NFDRS 1-day forecast’s accuracy; (iii) explore the impact of forecasting inaccuracy on wildfire activity across the conterminous US; and (iv) ascertain what outputs from the NFDRS relate most strongly to the formation of large wildfires. Firstly, this thesis shows that different regions of the US display different levels of correspondence between each observed fire danger indices and recorded fire activity. Areas in the Southern and Eastern Geographic Area Coordination Centers (GACCs) exhibit weaker correlations than those in the Northwest, Northern Rockies, Great Basin and Northern California GACCs. Peaks in fire occurrence are shown to occur at mid–low values of fire danger whereas final fire sizes increase monotonically with each fire danger index. Secondly, it is shown that the 1-day NFDRS forecasts have a strong correspondence with observed fire danger indices across the USA in the majority of locations. However, it is clear that there are multiple instances when these 1-day forecasts either over- or under-predict fire danger conditions, where there is systematic over-prediction of low-end fire danger values and under-prediction of high-end fire danger values. These predictive errors likely stem from errors in forecasted fire weather conditions, the subsequent derived fuel state and the reporting time of daily observations. Thirdly, when the inaccuracy of these forecasts was assessed spatially and temporally, the regions with the highest percentage of inaccurate forecasts were found to be in the Northern Rockies and Great Basin Geographic Area Coordination Centers (GACCs). Over-prediction was found to mainly occur between February and May, whilst peaks in the under-prediction of fire danger were found to be in spring and late summer. Finally, large wildfires appear to occur when fire danger indices are highly variable throughout the lifetime of a fire. As such this highlights the importance of considering daily variations in specific fire danger indices and that current understanding of variable fire danger conditions does not allow for the near-term prediction of large wildfire potential.

The ability to predict the temperatures in protected steel structures is of vital importance for the progress of fire safety engineering. Existing methods are limited in several respects, typically being computationally restricted and limited to examination of the performance of specific components. This thesis investigates a generalised CFDbased methodology for thermal analysis of structural members in fire, developed to overcome these limitations. A novel methodology has been developed, known as GeniSTELA (Generalised Solid ThErmal Analysis), which computes a “steel temperature field” parameter in each computational cell. The approach is based on a simplified 1D model for heat transfer, together with appropriate corrections for 2D and 3D effects, to provide a quasi- 3D solution with a reasonable computational cost. GeniSTELA has been implemented as a submodel within the SOFIE RANS CFD code. The basic operation of the model has been verified and results compared to the empirical methods in EC3, indicating a satisfactory performance. The role of the surface temperature prediction has been examined and demonstrated to be important for certain cases, justifying its inclusion in the generalised method. Validation of the model is undertaken with respect to standard testing in fire resistance furnaces, examining the fire ratings of different practical protection systems, and the BRE large compartment fire tests, which looked at protected steel indicatives in full-scale post-flashover fires; in both cases, a satisfactory agreement is achieved. Model sensitivities are reported which reveal the expected strong dependencies on certain properties of thermal protection materials.

First order fire effects in mixed grass and tallgrass prairies may differ between current and historic fire regimes. To determine potential differences, the thermal dynamics of nine prescribed grassland fires and six experimental fires were evaluated. Fires were instrumented with dataloggers and arrays of up to twelve thermocouples set at heights ranging from -5 cm to 300 cm. Soil moisture and texture were documented, along with fuel characteristics. A series of experimental fires allowed soil moisture to be manipulated while minimizing other variables. Maximum temperature for the prescribed fires was 875°C at 75cm, and for the experimental fires 920°C at 10 cm. In experimental fires, the greatest temperature difference was at the surface with the dry substrate averaging 130°C higher than saturated. Average temperatures at -1 cm differed by 33°C. At 60°C, residence times in dry substrate averaged almost four minutes, while the average for saturated treatment was only 1 second. Surface residence times on dry substrate averaged over 7 minutes, almost 3 times longer than saturated. Soil moisture was shown to influence relative humidity and fine fuel moisture near the ground surface. An increased evaporation of soil water at the surface is suggested by a slight drop in subsurface temperatures as the flaming front moves over the surface. These data suggest that soil moisture affects fire intensity, decreasing temperatures at all levels of a fire. Temperatures and residence times were compared with data from studies documenting temperatures significantly affecting seed germination and edaphic effects at and below the surface. Temperatures increasing the germination of some seeds were found at all heights. Temperatures documented can be expected to decrease organic matter content and aggregate stability at the surface, slightly increasing erodibility. Thermal dynamics from the fires in this study represent a broad range of grassland fires under conditions common for prescribed fire. Soil moisture appears to significantly affect temperatures and residence times below, at, and above the soil surface. Data were compared with output from FOFEM 5.2 to access the applicability of FOFEM for use in mixed grass and tallgrass prairie. FOFEM consistently underestimated soil heating by up to 419°C.

Thesis (Ph. D.)--University of Montana, 2006. / Title from title screen. Description based on contents viewed Mar. 30, 2007. Includes bibliographical references (p. 142-151).

Innovative restoration strategies are critically needed in the South Texas Plains for controlling increased Opuntia cacti invasions. Using a replicated and randomized experimental study, I have examined the effects of fire seasonality and herbivory on the dominant cacti and herbaceous plant species in this semi-arid ecosystem. Results from this study demonstrate that the combination of fire and wildlife herbivory significantly reduces Opuntia cactus cover. I was able to empirically demonstrate that prescribed fire decreases prickly pear cactus cover. Moreover, this decrease is further exacerbated by the effects of large mammalian herbivores consuming and/or disturbing recently burned mottes. In the absence of fire, both mottes with and without herbivore exclosures increased in size. The ecological insights gained from this study will contribute to the development of management strategies of Opuntia cacti, while promoting the restoration and long-term sustainability of Texas rangelands.

Viewing the economic development of the recent years, complying with the advancement of the time, the change of society and the development of the electronic technology, the probability to cause fire accident becomes much higher and it means the beginning of a serious disaster happened to human beings. Most of factories or companies where the people work inside are built towards high leveled, under grounded, large-sized, and getting more like closed areas, furthermore, the numbers of the companies making or supplying hazardous or dangerous materials gets more and more, this phenomenon causes the same result - that is wherever there is a fire, it will cause very serious loss about human lives & financial stuffs in an extremely short time. So being an modern people, we should put more focus on how to prevent the damages or reduce to the least ones caused by fire Due to the high price increase of the land, people want to fully utilize about the land efficiency, the architecture skill is developed towards building large-scaled ones, so the factories & electronic companies are mostly having big square-measured land, complicated structure, using special built material, containing many people in and even the building¡¦s usage becomes very complicated. All of these cause it extremely hard to make urgent rescues when there is a fire and will easily cause enormous loss about lives & stuffs. Most of the people think that it is the government & the fire fighting organization¡¦s responsibility to do the job about ¡§fire fight or fire prevention¡¨ and people always blame the fire fighting unit does not do their best to make rescues when there is a fire. While a complete fire fight & rescuing procedure has very timing concern, which includes perceiving about the fire clue, calling to report, initial fire extinction and control, guiding people to escape, safety protection, emergency protection and making complete fire extinction. In most cases, when the fire fighting unit arrives & starts to work on fire fight, the fire very likely grows to a certain burning phase, so the initial fire extinction will depend on the factory¡¦s ability to act about fire prevention and to deal with urgent situation, but due to the lack of the relative research about the factories & building¡¦s fire prevention in our country, and especially there is too few regarding the fire prevention strategy & safety management, this research majors to review the relative information to understand the connotation of the factory¡¦s fire fighting strategy and the law about safety management, and try to sieve the factors and its relative importance about the factory & building¡¦s fire prevention strategy from the actual examples of the fire accidents. As a matter of fact, this research is trying to bring up the importance about the factory & building¡¦s fire fighting strategy and its safety management, in order to promote the factory¡¦s efficiency about fire prevention management.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: building performance -- fire safety -- fire spread -- fire detection and initial action -- automatic sprinkler systems -- smoke movement, control and toxicity -- structural frame -- fire brigade intervention -- life safety. Includes bibliographical references.