WorldWideScience

Sample records for analysis fire simulation

  1. Sensitivity Analysis of Fire Dynamics Simulation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter V.; Petersen, Arnkell J.

    2007-01-01

    equations require solution of the issues of combustion and gas radiation to mention a few. This paper performs a sensitivity analysis of a fire dynamics simulation on a benchmark case where measurement results are available for comparison. The analysis is performed using the method of Elementary Effects...

  2. Sensitivity Analysis of Fire Dynamics Simulation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter V.; Petersen, Arnkell J.

    2007-01-01

    In case of fire dynamics simulation requirements to reliable results are most often very high due to the severe consequences of erroneous results. At the same time it is a well known fact that fire dynamics simulation constitutes rather complex physical phenomena which apart from flow and energy ...

  3. LNG pool fire simulation for domino effect analysis

    International Nuclear Information System (INIS)

    Masum Jujuly, Muhammad; Rahman, Aziz; Ahmed, Salim; Khan, Faisal

    2015-01-01

    A three-dimensional computational fluid dynamics (CFD) simulation of liquefied natural gas (LNG) pool fire has been performed using ANSYS CFX-14. The CFD model solves the fundamental governing equations of fluid dynamics, namely, the continuity, momentum and energy equations. Several built-in sub-models are used to capture the characteristics of pool fire. The Reynolds-averaged Navier–Stokes (RANS) equation for turbulence and the eddy-dissipation model for non-premixed combustion are used. For thermal radiation, the Monte Carlo (MC) radiation model is used with the Magnussen soot model. The CFD results are compared with a set of experimental data for validation; the results are consistent with experimental data. CFD results show that the wind speed has significant contribution on the behavior of pool fire and its domino effects. The radiation contours are also obtained from CFD post processing, which can be applied for risk analysis. The outcome of this study will be helpful for better understanding of the domino effects of pool fire in complex geometrical settings of process industries. - Highlights: • Simulation of pool fire using computational fluid dynamics (CFD) model. • Integration of CFD based pool fire model with domino effect. • Application of the integrated CFD based domino effect analysis

  4. Discrete Event Simulation for the Analysis of Artillery Fired Projectiles from Shore

    Science.gov (United States)

    2017-06-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS DISCRETE EVENT SIMULATION FOR THE ANALYSIS OF ARTILLERY FIRED PROJECTILES FROM SHORE by James...3. REPORT TYPE AND DATES COVERED Master’s Thesis 07-06-2015 to 06-16-2017 4. TITLE AND SUBTITLE DISCRETE EVENT SIMULATION FOR THE ANALYSIS OF...operations in the littorals. Expeditionary Fire Support Model–Maritime (EFSM) is a discrete event model that simulates current capabilities of Marine Corps

  5. Simulation analysis of the spread of fire through the program Fire Dynamics Simulator FDS in areas of fire of nuclear power plants; Analisis de simulacion de la propagacion de incendios mediante el programa Fire Dynamics Simulator FDS en areas de fuego de Centrales Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Salellas, J.; Zamora, I.; Fabbri, M.; Colomer, C.; Castillo, R.; Fradera, J.

    2014-07-01

    The objective of the analysis of the spread of fire through Computational Fluid Dynamics simulation with the Fire Dynamics Simulator program is to determine the identification of the affected computers and determine the livability in the areas of fire as fire postulates. The simulation with Fire Dynamics Simulator allows the evolution and spread of flame and smoke behavior in an instant in time, determining the exact moment that damage is caused by radiation or temperature to equipment and operation according to the level of toxicity and temperature of the fire area. (Author)

  6. Using the Large Fire Simulator System to map wildland fire potential for the conterminous United States

    Science.gov (United States)

    LaWen Hollingsworth; James Menakis

    2010-01-01

    This project mapped wildland fire potential (WFP) for the conterminous United States by using the large fire simulation system developed for Fire Program Analysis (FPA) System. The large fire simulation system, referred to here as LFSim, consists of modules for weather generation, fire occurrence, fire suppression, and fire growth modeling. Weather was generated with...

  7. A method for ensemble wildland fire simulation

    Science.gov (United States)

    Mark A. Finney; Isaac C. Grenfell; Charles W. McHugh; Robert C. Seli; Diane Trethewey; Richard D. Stratton; Stuart Brittain

    2011-01-01

    An ensemble simulation system that accounts for uncertainty in long-range weather conditions and two-dimensional wildland fire spread is described. Fuel moisture is expressed based on the energy release component, a US fire danger rating index, and its variation throughout the fire season is modeled using time series analysis of historical weather data. This analysis...

  8. Fire risk analysis, fire simulation, fire spreading and impact of smoke and heat on instrumentation electronics - State-of-the-Art Report

    International Nuclear Information System (INIS)

    Roewekamp, M.; Bertrand, R.; Bonneval, F.; Hamblen, D.; Siu, N.; Aulamo, H.; Martila, J.; Sandberg, J.; Virolainen, R.

    2000-01-01

    Numerous fire PSAs (probabilistic safety assessments) have shown that fire can be a major contributor to nuclear power plant risk. However, there are considerable uncertainties in the results of these assessments, due to significant gaps in current abilities to perform realistic assessments. These gaps involve multiple aspects of fire PSA, including the estimation of the probability of important fire scenarios, the modeling of fire growth and suppression, the prediction of fire-induced damage to equipment (including the effects of smoke), and the treatment of plant and operator responses to the fire. In response to recommendations of /VIR 93/, CSNI/PWG5 established a Task Group to review the present status and maturity of current methods used in fire risk assessments for operating nuclear power plants. The Task Group issued a questionnaire in May 1997 to all nuclear power generating OECD countries. The prime focus of the questionnaire (see Appendix A) was on a number of important issues in fire PSA: Fire PSA methodology and applications; Fire simulation codes; Ignition and damageability data; Modeling of fire spread on cables or other equipment; Modeling of smoke production and spread; Impact of smoke and heat on instrumentation, electronics, or other electrical equipment; Impact of actual cable fires on safety systems. The questionnaire requested specific information on these topics (e.g., computer codes used in fire PSAs, the physical parameters used to model ignition). Responses to the questionnaire were provided by Finland, France, Germany, Hungary, Japan, Spain, Switzerland, United Kingdom, and the USA. This report summarizes the questionnaire responses and thereby: a) provides a perspective on the current fire PSA state of the art (SOAR) with respect to the issues listed above, and b) provides numerous references for more detailed information regarding these issues. The main responsibility for writing different chapters of this report was divided between some

  9. Simulation of forced-ventilation fires

    International Nuclear Information System (INIS)

    Krause, F.R.; Gregory, W.S.

    1982-01-01

    Fire hazard descriptions and compartment fire models are assessed as input to airflow network analysis methods that simulate the exposure of ventilation system components to fire products. The assessment considered the availability of hazard descriptions and models for predicting simultaneous heat and mass release at special compartment openings that are characterized by a one-dimensional and controllable volumetric flux

  10. Computer simulations of a generic truck cask in a regulatory fire using the Container Analysis Fire Environment (CAFE) code

    International Nuclear Information System (INIS)

    Ju, H.; Greiner, M.; Suo-Anttila, A.

    2002-01-01

    The Container Analysis Fire Environment (CAFE) computer code is designed to predict accurately convection and radiation heat transfer to a thermally massive object engulfed in a large pool fire. It is well suited for design and risk analyses of spent nuclear fuel transport systems. CAFE employs computational fluid dynamics and several fire and radiation models. These models must be benchmarked using experimental results. In this paper, a set of wind velocity conditions are determined which allow CAFE accurately to reproduce recent heat transfer measurements for a thick walled calorimeter in a ST-1 regulatory pool fire. CAFE is then used to predict the response of an intack (thin walled) generic legal weight truck cask. The maximum temperatures reached by internal components are within safe limits. A simple 800 deg. C, grey-radiation fire model gives maximum component temperatures that are somewhat below those predicted by CAFE. (author)

  11. Global sensitivity analysis using emulators, with an example analysis of large fire plumes based on FDS simulations

    Energy Technology Data Exchange (ETDEWEB)

    Kelsey, Adrian [Health and Safety Laboratory, Harpur Hill, Buxton (United Kingdom)

    2015-12-15

    Uncertainty in model predictions of the behaviour of fires is an important issue in fire safety analysis in nuclear power plants. A global sensitivity analysis can help identify the input parameters or sub-models that have the most significant effect on model predictions. However, to perform a global sensitivity analysis using Monte Carlo sampling might require thousands of simulations to be performed and therefore would not be practical for an analysis based on a complex fire code using computational fluid dynamics (CFD). An alternative approach is to perform a global sensitivity analysis using an emulator. Gaussian process emulators can be built using a limited number of simulations and once built a global sensitivity analysis can be performed on an emulator, rather than using simulations directly. Typically reliable emulators can be built using ten simulations for each parameter under consideration, therefore allowing a global sensitivity analysis to be performed, even for a complex computer code. In this paper we use an example of a large scale pool fire to demonstrate an emulator based approach to global sensitivity analysis. In that work an emulator based global sensitivity analysis was used to identify the key uncertain model inputs affecting the entrainment rates and flame heights in large Liquefied Natural Gas (LNG) fire plumes. The pool fire simulations were performed using the Fire Dynamics Simulator (FDS) software. Five model inputs were varied: the fire diameter, burn rate, radiative fraction, computational grid cell size and choice of turbulence model. The ranges used for these parameters in the analysis were determined from experiment and literature. The Gaussian process emulators used in the analysis were created using 127 FDS simulations. The emulators were checked for reliability, and then used to perform a global sensitivity analysis and uncertainty analysis. Large-scale ignited releases of LNG on water were performed by Sandia National

  12. Global sensitivity analysis using emulators, with an example analysis of large fire plumes based on FDS simulations

    International Nuclear Information System (INIS)

    Kelsey, Adrian

    2015-01-01

    Uncertainty in model predictions of the behaviour of fires is an important issue in fire safety analysis in nuclear power plants. A global sensitivity analysis can help identify the input parameters or sub-models that have the most significant effect on model predictions. However, to perform a global sensitivity analysis using Monte Carlo sampling might require thousands of simulations to be performed and therefore would not be practical for an analysis based on a complex fire code using computational fluid dynamics (CFD). An alternative approach is to perform a global sensitivity analysis using an emulator. Gaussian process emulators can be built using a limited number of simulations and once built a global sensitivity analysis can be performed on an emulator, rather than using simulations directly. Typically reliable emulators can be built using ten simulations for each parameter under consideration, therefore allowing a global sensitivity analysis to be performed, even for a complex computer code. In this paper we use an example of a large scale pool fire to demonstrate an emulator based approach to global sensitivity analysis. In that work an emulator based global sensitivity analysis was used to identify the key uncertain model inputs affecting the entrainment rates and flame heights in large Liquefied Natural Gas (LNG) fire plumes. The pool fire simulations were performed using the Fire Dynamics Simulator (FDS) software. Five model inputs were varied: the fire diameter, burn rate, radiative fraction, computational grid cell size and choice of turbulence model. The ranges used for these parameters in the analysis were determined from experiment and literature. The Gaussian process emulators used in the analysis were created using 127 FDS simulations. The emulators were checked for reliability, and then used to perform a global sensitivity analysis and uncertainty analysis. Large-scale ignited releases of LNG on water were performed by Sandia National

  13. Proof of safer operation of power station plant during a fire by linking in fire simulation and system technical analysis

    International Nuclear Information System (INIS)

    Hensel, W.; Beyer, H.; Samman, A.

    1997-01-01

    In order to attain the basic aims of protection in power station plant, a series of systems, which must be available also in the event of a fire, are provided. The thermal loads for the systems and components which are necessary to attain the aims of protection are ascertained by means of a simulation of the cause of the fire for the specific scenario. Statements on the availability of the systems and components in the specific scenario are derived from the design values used as the basis. (orig.) [de

  14. CERN Fire Brigade rescue simulation

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The CERN Fire Brigade is made up of experienced firemen from all of the 20 Member States. In these images they are seen at a 'Discovery Monday' held at the Microcosm exhibition. Here visitors learn how the Fire Brigade deal with various situations, including a simulated cave rescue performed by the Hazardous Environments Response Team.

  15. Strain gauge analysis of the effect of porcelain firing simulation on the prosthetic misfit of implant-supported frameworks.

    Science.gov (United States)

    De Vasconcellos, Diego Klee; Özcan, Mutlu; Maziero Volpato, Cláudia Ângela; Bottino, Marco Antonio; Yener, Esra Salihoğlu

    2012-06-01

    This study investigated the effect of porcelain firing on the misfit of implant-supported frameworks and analyzed the influence of preheat treatment on the dimensional alterations. Four external-hex cylindrical implants were placed in polyurethane block. Ten frameworks of screw-retained implant-supported prostheses were cast in Pd-Ag using 2 procedures: (1) control group (CG, n = 5): cast in segments and laser welded; and test group (TG, n = 5): cast in segments, preheated, and laser welded. All samples were subjected to firing to simulate porcelain veneering firing. Strain gauges were bonded around the implants, and microstrain values (με = 10⁻⁶ε) were recorded after welding (M1), oxidation cycle (M2), and glaze firing (M3). Data were statistically analyzed (2-way analysis of variance, Bonferroni, α = 0.05). The microstrain value in the CG at M3 (475.2 με) was significantly different from the values observed at M1 (355.6 με) and M2 (413.9 με). The values at M2 and M3 in the CG were not statistically different. Microstrain values recorded at different moments (M1: 361.6 με/M2: 335.3 με/M3: 307.2 με) did not show significant difference. The framework misfit deteriorates during firing cycles of porcelain veneering. Metal distortion after porcelain veneering could be controlled by preheat treatment.

  16. Ames T-3 fire test facility - Aircraft crash fire simulation

    Science.gov (United States)

    Fish, R. H.

    1976-01-01

    There is a need to characterize the thermal response of materials exposed to aircraft fuel fires. Large scale open fire tests are costly and pollute the local environment. This paper describes the construction and operation of a subscale fire test that simulates the heat flux levels and thermochemistry of typical open pool fires. It has been termed the Ames T-3 Test and has been used extensively by NASA since 1969 to observe the behavior of materials exposed to JP-4 fuel fires.

  17. Risk Assessment of the Main Control Room Fire Using Fire Simulations

    International Nuclear Information System (INIS)

    Kang, Dae Il; Kim, Kilyoo; Jang, Seung Cheol

    2013-01-01

    KAERI is performing a fire PSA for a reference plant, Ulchin Unit 3, as part of developing the Korean site risk profile (KSRP). Fire simulations of the MCR fire were conducted using the CFAST (Consolidated Fire Growth and Smoke Transport) model and FDS (fire dynamic simulator) to improve the uncertainty in the MCR fire risk analysis. Using the fire simulation results, the MCR abandonment risk was evaluated. Level 1 PSA (probabilistic safety assessment) results of Ulchin Unit 3 using the EPRI PRA (probabilistic risk assessment) implementation guide showed that the MCR (main control room) fire was the main contributor to the core damage frequency. Recently, U. S. NRC and EPRI developed NUREG/CR-6850 to provide state-of-the-art methods, tools, and data for the conduct of a fire PSA for a commercial NPP

  18. Design of Experiment and Analysis for the Joint Dynamic Allocation of Fires and Sensors (JDAFS) Simulation

    National Research Council Canada - National Science Library

    Freye, Jeffrey T

    2007-01-01

    ...) model, a low-resolution, Discrete Event Simulation Model with embedded optimization enables the analysis of many scenarios and factors to explore Joint Intelligence, Surveillance, and Reconnaissance (ISR) missions...

  19. Experimental Benchmarking of Fire Modeling Simulations. Final Report

    International Nuclear Information System (INIS)

    Greiner, Miles; Lopez, Carlos

    2003-01-01

    A series of large-scale fire tests were performed at Sandia National Laboratories to simulate a nuclear waste transport package under severe accident conditions. The test data were used to benchmark and adjust the Container Analysis Fire Environment (CAFE) computer code. CAFE is a computational fluid dynamics fire model that accurately calculates the heat transfer from a large fire to a massive engulfed transport package. CAFE will be used in transport package design studies and risk analyses

  20. Computer simulation of the fire-tube boiler hydrodynamics

    Directory of Open Access Journals (Sweden)

    Khaustov Sergei A.

    2015-01-01

    Full Text Available Finite element method was used for simulating the hydrodynamics of fire-tube boiler with the ANSYS Fluent 12.1.4 engineering simulation software. Hydrodynamic structure and volumetric temperature distribution were calculated. The results are presented in graphical form. Complete geometric model of the fire-tube boiler based on boiler drawings was considered. Obtained results are suitable for qualitative analysis of hydrodynamics and singularities identification in fire-tube boiler water shell.

  1. Large eddy simulation of compartment fires

    Science.gov (United States)

    Trouvé, Arnaud; Wang, Yi

    2010-12-01

    This paper is aimed at illustrating the capabilities of contemporary large eddy simulation (LES) solvers for compartment fire applications. Compartment fires refer to fires occurring indoors and feature a variety of complex phenomena associated with smoke accumulation and restricted air ventilation. The article provides a brief presentation of the main features of compartment fire dynamics followed by a review of the modelling challenges found in a LES treatment of these dominant features. The discussion shows that in addition to a suitable model for the turbulent flow dynamics, simulations of compartment fires require a collection of physical sub-models in order to describe a large range of multi-physics phenomena, including pyrolysis processes, buoyancy-driven flow, combustion, soot formation and thermal radiation. Some examples of LES simulations of compartment fires are also presented, using two different solvers that represent the current state-of-the-art of compartment fire modelling: FDS developed by the National Institute of Standards and Technology, USA, and FireFOAM developed by FM Global, USA. Both solvers are available as free open-source software and are representative of ongoing efforts within the fire research and engineering community to self-organise and to promote the general area of LES-based fire modelling.

  2. FIRE HAZARDS ANALYSIS - BUSTED BUTTE

    International Nuclear Information System (INIS)

    Longwell, R.; Keifer, J.; Goodin, S.

    2001-01-01

    The purpose of this fire hazards analysis (FHA) is to assess the risk from fire within individual fire areas at the Busted Butte Test Facility and to ascertain whether the DOE fire safety objectives are met. The objective, identified in DOE Order 420.1, Section 4.2, is to establish requirements for a comprehensive fire and related hazards protection program for facilities sufficient to minimize the potential for: (1) The occurrence of a fire related event. (2) A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees. (3) Vital DOE programs suffering unacceptable interruptions as a result of fire and related hazards. (4) Property losses from a fire and related events exceeding limits established by DOE. Critical process controls and safety class systems being damaged as a result of a fire and related events

  3. Coupled numerical simulation of fire in tunnel

    Science.gov (United States)

    Pesavento, F.; Pachera, M.; Schrefler, B. A.; Gawin, D.; Witek, A.

    2018-01-01

    In this work, a coupling strategy for the analysis of a tunnel under fire is presented. This strategy consists in a "one-way" coupling between a tool considering the computational fluid dynamics and radiation with a model treating concrete as a multiphase porous material exposed to high temperature. This global approach allows for taking into account in a realistic manner the behavior of the "system tunnel", composed of the fluid and the solid domain (i.e. the concrete structures), from the fire onset, its development and propagation to the response of the structure. The thermal loads as well as the moisture exchange between the structure surface and the environment are calculated by means of computational fluid dynamics. These set of data are passed in an automatic way to the numerical tool implementing a model based on Multiphase Porous Media Mechanics. Thanks to this strategy the structural verification is no longer based on the standard fire curves commonly used in the engineering practice, but it is directly related to a realistic fire scenario. To show the capability of this strategy some numerical simulations of a fire in the Brenner Base Tunnel, under construction between Italy and Austria, is presented. The numerical simulations show the effects of a more realistic distribution of the thermal loads with respect to the ones obtained by using the standard fire curves. Moreover, it is possible to highlight how the localized thermal load generates a non-uniform pressure rise in the material, which results in an increase of the structure stress state and of the spalling risk. Spalling is likely the most dangerous collapse mechanism for a concrete structure. This coupling approach still represents a "one way" strategy, i.e. realized without considering explicitly the mass and energy exchange from the structure to the fluid through the interface. This results in an approximation, but from physical point of view the current form of the solid-fluid coupling is

  4. COMPUTATIONAL SIMULATION OF FIRE DEVELOPMENT INSIDE A TRADE CENTRE

    Directory of Open Access Journals (Sweden)

    Constantin LUPU

    2015-07-01

    Full Text Available Real scale fire experiments involve considerable costs compared to computational mathematical modelling. This paperwork is the result of such a virtual simulation of a fire occurred in a hypothetical wholesale warehouse comprising a large number of trade stands. The analysis starts from the ignition source located inside a trade stand towards the fire expansion over three groups of compartments, by highlighting the heat transfer, both in small spaces, as well as over large distances. In order to confirm the accuracy of the simulation, the obtained values are compared to the ones from the specialized literature.

  5. A Comparison of Live and Simulated Fire Soldier Shooting Performance

    National Research Council Canada - National Science Library

    Scribner, David R; Wiley, Patrick H; Harper, William H

    2007-01-01

    .... This is true for marksmanship and engagement shooting trainers as well. Many marksmanship studies have used simulated fire, but not many of these simulators have been validated with a live fire comparison. The U.S...

  6. Collection and analysis of wind data for the evaluation of Wildland-Urban Interface Fire Dynamics Simulator

    Science.gov (United States)

    Espina, Chad Edward Obedoza

    The Wildland Urban-Interface Fire Dynamics Simulator (WFDS) is a computer code that is currently being developed by the National Institute of Standards and Technology (NIST). WFDS has the capability of simulating wildland fire behavior with prescribed elements such vegetative and structural fuel, topography, and weather conditions. In this initial stage of the research, support for the development of WFDS focuses on the evaluation of a wind flow simulation on a very complex, outdoor terrain. This effort is preceded by the fabrication, installation and testing of wind-sensing equipment. Foremost, wind data gathered from different sites using various instruments are compared and evaluated. The data gathered in the Trails community of Rancho Bernardo is then presented and compared to select WFDS simulations. Systems consisting of a wind vane and anemometer are currently installed in the Trails community of Rancho Bernardo. They were installed by Professor Fletcher J. Miller and me using a lift that is attached to a telescoping crane. These instruments will gather the wind data needed to show the behavioral patterns of winds influenced by the topography and obstructions such as trees and houses. They are currently installed on top of light posts. These light posts were picked based on the path of the fire influenced by the Santa Ana winds that ravaged the community in 2007. The data from these instruments were graphically represented using a Matlab code that was developed specifically for the data sets. The Matlab graphing utility plots wind speed and wind direction along with matching polar plots. Other main features also include the ability to set a time range and compare two sites in one plot. There are other wind instruments currently being tested and being analyzed to ensure correct data is being recorded. These instruments will also expand to a wider range the wind data-gathering capabilities vertically. A Sound Detecting and Ranging (SoDAR) unit gathers wind

  7. Simulated western spruce budworm defoliation reduces torching and crowning potential: A sensitivity analysis using a physics-based fire model

    Science.gov (United States)

    Gregory M. Cohn; Russell A. Parsons; Emily K. Heyerdahl; Daniel G. Gavin; Aquila Flower

    2014-01-01

    The widespread, native defoliator western spruce budworm (Choristoneura occidentalis Freeman) reduces canopy fuels, which might affect the potential for surface fires to torch (ignite the crowns of individual trees) or crown (spread between tree crowns). However, the effects of defoliation on fire behaviour are poorly understood. We used a physics-based fire model to...

  8. Motorcoach Fire Safety Analysis.

    Science.gov (United States)

    2009-07-01

    This purpose of this study was to collect and analyze information from Government, industry, and media sources on the causes, frequency, and severity of motorcoach fires in the U.S., and to identify potential risk reduction measures. The Volpe Center...

  9. A fire management simulation model using stochastic arrival times

    Science.gov (United States)

    Eric L. Smith

    1987-01-01

    Fire management simulation models are used to predict the impact of changes in the fire management program on fire outcomes. As with all models, the goal is to abstract reality without seriously distorting relationships between variables of interest. One important variable of fire organization performance is the length of time it takes to get suppression units to the...

  10. The French fire protection concept. Vulnerability analysis

    International Nuclear Information System (INIS)

    Kaercher, M.

    1998-01-01

    The French fire protection concept is based on a principle of three levels of defence in depth: fire prevention, fire containing and fire controlling. Fire prevention is based on arrangements which prevent the fire from starting or which make difficult for the fire to start. Fire containing is based on design measures so that the fire will have no impact on the safety of the installation. For fire controlling, equipment nad personnel are on duty in order to detect, to fight and to gain control over the fire as early as possible. The French fire protection concept gives priority to fire containing based on passive structural measures. All buildings containing safety equipment are divided into fire compartments (or fire areas) and fire cells (or fire zones). Basically, a compartment houses safety equipment belonging to one division (or train) so that the other division is always available to reach the plant safe shut down or to mitigate an accident. Because there is a large number of fire compartments and fire cells, deviations from the general principle can be observed. To this reason the RCC-I (Design and Construction Rules applicable for fire protection) requires to implement an assessment of the principle of division. This assessment is called vulnerability analysis. The vulnerability analysis is usually performed at the end of the project, before erection. It is also possible to perform a vulnerability analysis in an operating nuclear power plant in the scope of a fire safety upgrading programme. In the vulnerability analysis, the functional failure of all the equipment (except for those protected by a qualified fire barrier, designed or able to withstand the fire consequences) within the fire compartment or cell, where the fire breaks out, is postulated. The potential consequences for the plant safety are analysed

  11. Davis Fire: Fire behavior and fire effects analysis

    Science.gov (United States)

    LaWen T. Hollingsworth

    2010-01-01

    The Davis Fire presents an interesting example of fire behavior in subalpine fir, partially dead lodgepole pine with multiple age classes, and moist site Douglas-fir vegetation types. This has been summer of moderate temperatures and intermittent moisture that has kept live herbaceous and live woody moistures fairly high and dead fuel moistures at a moderate level....

  12. FARSITE: a fire area simulator for fire managers

    Science.gov (United States)

    Mark A. Finney

    1995-01-01

    A fire growth model (FARSITE) has been developed for use on personal computers (PC’s). Because PC’s are commonly used by land and fire managers, this portable platform would be an accustomed means to bring fire growth modeling technology to management applications. The FARSITE model is intended for use in projecting the growth of prescribed natural fires for wilderness...

  13. Advanced methods for a probabilistic safety analysis of fires. Development of advanced methods for performing as far as possible realistic plant specific fire risk analysis (fire PSA)

    International Nuclear Information System (INIS)

    Hofer, E.; Roewekamp, M.; Tuerschmann, M.

    2003-07-01

    In the frame of the research project RS 1112 'Development of Methods for a Recent Probabilistic Safety Analysis, Particularly Level 2' funded by the German Federal Ministry of Economics and Technology (BMWi), advanced methods, in particular for performing as far as possible realistic plant specific fire risk analyses (fire PSA), should be developed. The present Technical Report gives an overview on the methodologies developed in this context for assessing the fire hazard. In the context of developing advanced methodologies for fire PSA, a probabilistic dynamics analysis with a fire simulation code including an uncertainty and sensitivity study has been performed for an exemplary scenario of a cable fire induced by an electric cabinet inside the containment of a modern Konvoi type German nuclear power plant taking into consideration the effects of fire detection and fire extinguishing means. With the present study, it was possible for the first time to determine the probabilities of specified fire effects from a class of fire events by means of probabilistic dynamics supplemented by uncertainty and sensitivity analyses. The analysis applies a deterministic dynamics model, consisting of a dynamic fire simulation code and a model of countermeasures, considering effects of the stochastics (so-called aleatory uncertainties) as well as uncertainties in the state of knowledge (so-called epistemic uncertainties). By this means, probability assessments including uncertainties are provided to be used within the PSA. (orig.) [de

  14. Fire in longleaf pine stand management: an economic analysis

    Science.gov (United States)

    Rodney L. Busby; Donald G. Hodges

    1999-01-01

    A simulation analysis of the economics of using prescribed fire as a forest management tool in the management of longleaf pine (Pinus palustris Mill.) plantations was conducted. A management regime using frequent prescribed fire was compared to management regimes involving fertilization and chemical release, chemical control, and mechanical control. Determining the...

  15. Simulating wall and corner fire tests on wood products with the OSU room fire model

    Science.gov (United States)

    H. C. Tran

    1994-01-01

    This work demonstrates the complexity of modeling wall and corner fires in a compartment. The model chosen for this purpose is the Ohio State University (OSU) room fire model. This model was designed to simulate fire growth on walls in a compartment and therefore lends itself to direct comparison with standard room test results. The model input were bench-scale data...

  16. Sensitivity of fire behavior simulations to fuel model variations

    Science.gov (United States)

    Lucy A. Salazar

    1985-01-01

    Stylized fuel models, or numerical descriptions of fuel arrays, are used as inputs to fire behavior simulation models. These fuel models are often chosen on the basis of generalized fuel descriptions, which are related to field observations. Site-specific observations of fuels or fire behavior in the field are not readily available or necessary for most fire management...

  17. Numerical simulation of a biomass fired grate boiler

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

    2006-01-01

    Computational fluid dynamic (CFD) analysis of the thermal flow in the combustion furnace of a biomass-fired grate boiler provides crucial insight into the boiler's performance. Quite a few factors play important roles in a general CFD analysis, such as grid, models, discretization scheme and so on....... For a grate boiler, the modeling the interaction of the fuel bed and the gas phase above the bed is also essential. Much effort can be found in literature on developing bed models whose results are introduced into CFD simulations of freeboard as inlet conditions. This paper presents a CFD analysis...... of the largest biomass-fired grate boiler in Denmark. The focus of this paper is to study how significantly an accurate bed model can affect overall CFD results, i.e., how necessarily it is to develop an accurate bed model in terms of the reliability of CFD results. The ultimate purpose of the study is to obtain...

  18. Corrosion behaviour and surface analysis of a Co-Cr and two Ni-Cr dental alloys before and after simulated porcelain firing.

    Science.gov (United States)

    Qiu, Jing; Yu, Wei-Qiang; Zhang, Fu-Qiang; Smales, Roger J; Zhang, Yi-Lin; Lu, Chun-Hui

    2011-02-01

    This study evaluated the corrosion behaviour and surface properties of a commercial cobalt-chromium (Co-Cr) alloy and two nickel-chromium (Ni-Cr) alloys [beryllium (Be)-free and Be-containing] before and after a simulated porcelain-firing process. Before porcelain firing, the microstructure, surface composition and hardness, electrochemical corrosion properties, and metal-ion release of as-cast alloy specimens were examined. After firing, similar alloy specimens were examined for the same properties. In both as-cast and fired conditions, the Co-Cr alloy (Wirobond C) showed significantly more resistance to corrosion than the two Ni-Cr alloys. After firing, the corrosion rate of the Be-free Ni-Cr alloy (Stellite N9) increased significantly, which corresponded to a reduction in the levels of Cr, molybdenum (Mo), and Ni in the surface oxides and to a reduction in the thickness of the surface oxide film. The corrosion properties of the Co-Cr alloy and the Be-containing Ni-Cr alloy (ChangPing) were not significantly affected by the firing process. Porcelain firing also changed the microstructure and microhardness values of the alloys, and there were increases in the release of Co and Ni ions, especially for Ni from the Be-free Ni-Cr alloy. Thus, the corrosion rate of the Be-free Ni-Cr alloy increased significantly after porcelain firing, whereas the firing process had little effect on the corrosion susceptibility of the Co-Cr alloy and the Be-containing Ni-Cr alloy. © 2011 Eur J Oral Sci.

  19. Live tree carbon stock equivalence of fire and fuels extension to the Forest Vegetation Simulator and Forest Inventory and Analysis approaches

    Science.gov (United States)

    James E. Smith; Coeli M. Hoover

    2017-01-01

    The carbon reports in the Fire and Fuels Extension (FFE) to the Forest Vegetation Simulator (FVS) provide two alternate approaches to carbon estimates for live trees (Rebain 2010). These are (1) the FFE biomass algorithms, which are volumebased biomass equations, and (2) the Jenkins allometric equations (Jenkins and others 2003), which are diameter based. Here, we...

  20. Probabilistic methods in fire-risk analysis

    International Nuclear Information System (INIS)

    Brandyberry, M.D.

    1989-01-01

    The first part of this work outlines a method for assessing the frequency of ignition of a consumer product in a building and shows how the method would be used in an example scenario utilizing upholstered furniture as the product and radiant auxiliary heating devices (electric heaters, wood stoves) as the ignition source. Deterministic thermal models of the heat-transport processes are coupled with parameter uncertainty analysis of the models and with a probabilistic analysis of the events involved in a typical scenario. This leads to a distribution for the frequency of ignition for the product. In second part, fire-risk analysis as currently used in nuclear plants is outlines along with a discussion of the relevant uncertainties. The use of the computer code COMPBRN is discussed for use in the fire-growth analysis along with the use of response-surface methodology to quantify uncertainties in the code's use. Generalized response surfaces are developed for temperature versus time for a cable tray, as well as a surface for the hot gas layer temperature and depth for a room of arbitrary geometry within a typical nuclear power plant compartment. These surfaces are then used to simulate the cable tray damage time in a compartment fire experiment

  1. Simulation of Burn Probabilities and Fire Size Distributions for the Western United States

    Science.gov (United States)

    Finney, M.

    2009-04-01

    This simulation research was conducted on behalf of five U.S. land management agencies in order to develop a fire risk assessment system for the contiguous land area of the United States. The requirements included generating burn probabilities, characterizing fire behavior variation, and providing a means to evaluate sensitivity to both fire suppression and fuel treatment effects. This paper presents the methods and results of wildland fire size distributions and burn probabilities that were simulated for large units of land that together comprised the entire western United States. The outputs of these simulations are compared with historic data from Federal lands. The methods involved simulating fire ignition and growth for 10,000 to 20,000 "years" of artificial weather. The fire growth simulations were based on previously published methods (Finney 1998, 2002) and, when run repeatedly with different weather and ignition locations, produce fire behavior distributions at each landscape location (e.g. a "cell"). The artificial weather was generated using 1) a time-series analysis of recorded fire danger rating indices for each land unit that served as a proxy of daily and seasonal variation in fuel moisture, and 2) distributions of wind speed and direction from weather records in each unit. The simulations also required spatial data on fuel structure and topography which were provided by the LandFire project for the study area (http://www.landfire.gov). The occurrence and frequency of ignitions were simulated stochastically using empirical relationships that predicted the probability of large fire occurrence from the fire danger rating index. Fire suppression was represented using a modeling analysis of 453 large fires that was used to predict the probability of fire containment (by suppression forces) based on independent predictors of fire growth rates and fuel type. Fuel treatments were implemented into the fuel structure of the landscape to evaluate how these

  2. OR fire virtual training simulator: design and face validity.

    Science.gov (United States)

    Dorozhkin, Denis; Olasky, Jaisa; Jones, Daniel B; Schwaitzberg, Steven D; Jones, Stephanie B; Cao, Caroline G L; Molina, Marcos; Henriques, Steven; Wang, Jinling; Flinn, Jeff; De, Suvranu

    2017-09-01

    The Virtual Electrosurgical Skill Trainer is a tool for training surgeons the safe operation of electrosurgery tools in both open and minimally invasive surgery. This training includes a dedicated team-training module that focuses on operating room (OR) fire prevention and response. The module was developed to allow trainees, practicing surgeons, anesthesiologist, and nurses to interact with a virtual OR environment, which includes anesthesia apparatus, electrosurgical equipment, a virtual patient, and a fire extinguisher. Wearing a head-mounted display, participants must correctly identify the "fire triangle" elements and then successfully contain an OR fire. Within these virtual reality scenarios, trainees learn to react appropriately to the simulated emergency. A study targeted at establishing the face validity of the virtual OR fire simulator was undertaken at the 2015 Society of American Gastrointestinal and Endoscopic Surgeons conference. Forty-nine subjects with varying experience participated in this Institutional Review Board-approved study. The subjects were asked to complete the OR fire training/prevention sequence in the VEST simulator. Subjects were then asked to answer a subjective preference questionnaire consisting of sixteen questions, focused on the usefulness and fidelity of the simulator. On a 5-point scale, 12 of 13 questions were rated at a mean of 3 or greater (92%). Five questions were rated above 4 (38%), particularly those focusing on the simulator effectiveness and its usefulness in OR fire safety training. A total of 33 of the 49 participants (67%) chose the virtual OR fire trainer over the traditional training methods such as a textbook or an animal model. Training for OR fire emergencies in fully immersive VR environments, such as the VEST trainer, may be the ideal training modality. The face validity of the OR fire training module of the VEST simulator was successfully established on many aspects of the simulation.

  3. Numerical simulation methods of fires in nuclear power plants

    International Nuclear Information System (INIS)

    Keski-Rahkonen, O.; Bjoerkman, J.; Heikkilae, L.

    1992-01-01

    Fire is a significant hazard to the safety of nuclear power plants (NPP). Fire may be serious accident as such, but even small fire at a critical point in a NPP may cause an accident much more serious than fire itself. According to risk assessments a fire may be an initial cause or a contributing factor in a large part of reactor accidents. At the Fire Technology and the the Nuclear Engineering Laboratory of the Technical Research Centre of Finland (VTT) fire safety research for NPPs has been carried out in a large extent since 1985. During years 1988-92 a project Advanced Numerical Modelling in Nuclear Power Plants (PALOME) was carried out. In the project the level of numerical modelling for fire research in Finland was improved by acquiring, preparing for use and developing numerical fire simulation programs. Large scale test data of the German experimental program (PHDR Sicherheitsprogramm in Kernforschungscentral Karlsruhe) has been as reference. The large scale tests were simulated by numerical codes and results were compared to calculations carried out by others. Scientific interaction with outstanding foreign laboratories and scientists has been an important part of the project. This report describes the work of PALOME-project carried out at the Fire Technology Laboratory only. A report on the work at the Nuclear Engineering Laboratory will be published separatively. (au)

  4. The use of CAFE-3D for the simulation of tunnel fires

    International Nuclear Information System (INIS)

    Lopez, C.; Koski, J.A.; Hohnstreiter, G.F.; Khalil, I.; Suo-Anttila, A.

    2004-01-01

    Fires after accidents inside tunnels, such as the July 2001 Howard Street Tunnel fire in Baltimore, Maryland, USA, have raised stakeholder questions concerning the survivability of a spent nuclear fuel (SNF) transport cask when exposed to similar thermal environments. The analysis of tunnel fires is a computational challenge because of the need for very large computational domains in order to fully simulate such a problem. In this paper, the analyses of two different tunnel fire scenarios are described and the performance of typical SNF casks when exposed to these tunnel fire environments is discussed. The CAFE-3D fire code is used to model a series of fires inside tunnels, and the thermal performance of a SNF transportation cask within such fire environments is estimated with the use of the MSC PATRAN-P/Thermal finite element analysis code. The methodology used to simulate this type of fire scenario as well as a description of the manner in which the CAFE code couples the computational fluid dynamics and the finite element analysis techniques are also presented

  5. Analysing initial attack on wildland fires using stochastic simulation.

    Science.gov (United States)

    Jeremy S. Fried; J. Keith Gilless; James. Spero

    2006-01-01

    Stochastic simulation models of initial attack on wildland fire can be designed to reflect the complexity of the environmental, administrative, and institutional context in which wildland fire protection agencies operate, but such complexity may come at the cost of a considerable investment in data acquisition and management. This cost may be well justified when it...

  6. STRUCTURAL TEST AND ANALYSIS OF RC SLAB AFTER FIRE LOADING

    Directory of Open Access Journals (Sweden)

    CHUL-HUN CHUNG

    2013-04-01

    Full Text Available In the present study the behavior of fire and the residual strength of fire-ignited RC slabs are investigated by experimental tests and numerical simulations. The fire tests of RC slabs were carried out in a furnace using the ISO 834 standard fire. The load capacity of the cooled RC slabs that were not loaded during the fire tests was evaluated by additional 3 point bending tests. The influence of the proportion of PP (polypropylene fibers in the RC slabs on the structural behavior of the RC slabs after the fire loading was investigated. The results of the fire tests showed that the maximum temperature of concrete with PP fiber was lower than that of concrete without PP fiber. As the concrete was heated, the ultimate compressive strength decreased and the ultimate strain increased. The load-deflection relations of RC slabs after fire loading were compared by using existing stress-strain-temperature models. The comparison between the numerical analysis and the experimental tests showed that some numerical analyses were reliable and therefore, can be applied to evaluate the ultimate load of RC slabs after fire loading. The ultimate load capacity after cooling down the RC slabs without PP fiber showed a considerable reduction from that of the RC slabs with PP fiber.

  7. Structural Test and Analysis of RC Slab After Fire Loading

    International Nuclear Information System (INIS)

    Chung, Chulhun; Im, Cho Rong; Park, Jaegyun

    2013-01-01

    In the present study the behavior of fire and the residual strength of fire-ignited RC slabs are investigated by experimental tests and numerical simulations. The fire tests of RC slabs were carried out in a furnace using the ISO 834 standard fire. The load capacity of the cooled RC slabs that were not loaded during the fire tests was evaluated by additional 3 point bending tests. The influence of the proportion of PP (polypropylene) fibers in the RC slabs on the structural behavior of the RC slabs after the fire loading was investigated. The results of the fire tests showed that the maximum temperature of concrete with PP fiber was lower than that of concrete without PP fiber. As the concrete was heated, the ultimate compressive strength decreased and the ultimate strain increased. The load-deflection relations of RC slabs after fire loading were compared by using existing stress-strain-temperature models. The comparison between the numerical analysis and the experimental tests showed that some numerical analyses were reliable and therefore, can be applied to evaluate the ultimate load of RC slabs after fire loading. The ultimate load capacity after cooling down the RC slabs without PP fiber showed a considerable reduction from that of the RC slabs with PP fiber

  8. Exploratory Studies Facility Subsurface Fire Hazards Analysis

    International Nuclear Information System (INIS)

    Kubicek, J. L.

    2001-01-01

    The primary objective of this Fire Hazard Analysis (FHA) is to confirm the requirements for a comprehensive fire and related hazards protection program for the Exploratory Studies Facility (ESF) are sufficient to minimize the potential for: (1) The occurrence of a fire or related event. (2) A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees, the public or the environment. (3) Vital US. Department of Energy (DOE) programs suffering unacceptable interruptions as a result of fire and related hazards. (4) Property losses from a fire and related events exceeding limits established by DOE. (5) Critical process controls and safety class systems being damaged as a result of a fire and related events

  9. Exploratory Studies Facility Subsurface Fire Hazards Analysis

    International Nuclear Information System (INIS)

    Logan, Richard C.

    2002-01-01

    The primary objective of this Fire Hazard Analysis (FHA) is to confirm the requirements for a comprehensive fire and related hazards protection program for the Exploratory Studies Facility (ESF) are sufficient to minimize the potential for: The occurrence of a fire or related event; A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees, the public or the environment; Vital U.S. Department of Energy (DOE) programs suffering unacceptable interruptions as a result of fire and related hazards; Property losses from a fire and related events exceeding limits established by DOE; and Critical process controls and safety class systems being damaged as a result of a fire and related events

  10. Fire hazard analysis for the fuel supply shutdown storage buildings

    International Nuclear Information System (INIS)

    REMAIZE, J.A.

    2000-01-01

    The purpose of a fire hazards analysis (FHA) is to comprehensively assess the risk from fire and other perils within individual fire areas in a DOE facility in relation to proposed fire protection so as to ascertain whether the objectives of DOE 5480.7A, Fire Protection, are met. This Fire Hazards Analysis was prepared as required by HNF-PRO-350, Fire Hazards Analysis Requirements, (Reference 7) for a portion of the 300 Area N Reactor Fuel Fabrication and Storage Facility

  11. Dynamic model of Fire Growth in Abernethy Estate and Glen Tanar using FARSITE simulator

    OpenAIRE

    Grabowiecka, Magdalena

    2008-01-01

    Most of the vegetation fires in Great Britain are of an anthropogenic nature. The possibility of a wildfire occurrence depends on the combination of human behaviour, the type and condition of the vegetation and the weather conditions. By using FARSITE – Fire Area Simulator it is easy to develop a two-dimensional output such as Fire Growth model on personal computer. The simulator incorporates existing fire behaviour models of surface fire spread, crown fire, fire acceleration, fuel moisture a...

  12. Using fire dynamics simulator to reconstruct a hydroelectric power plant fire accident.

    Science.gov (United States)

    Chi, Jen-Hao; Wu, Sheng-Hung; Shu, Chi-Min

    2011-11-01

    The location of the hydroelectric power plant poses a high risk to occupants seeking to escape in a fire accident. Calculating the heat release rate of transformer oil as 11.5 MW/m(2), the fire at the Taiwan Dajia-River hydroelectric power plant was reconstructed using the fire dynamics simulator (FDS). The variations at the escape route of the fire hazard factors temperature, radiant heat, carbon monoxide, and oxygen were collected during the simulation to verify the causes of the serious casualties resulting from the fire. The simulated safe escape time when taking temperature changes into account is about 236 sec, 155 sec for radiant heat changes, 260 sec for carbon monoxide changes, and 235-248 sec for oxygen changes. These escape times are far less than the actual escape time of 302 sec. The simulation thus demonstrated the urgent need to improve escape options for people escaping a hydroelectric power plant fire. © 2011 American Academy of Forensic Sciences.

  13. Analysis of Fire Data in Oman

    Directory of Open Access Journals (Sweden)

    K.S. Al-Jabri

    2003-06-01

    Full Text Available The aim of this study is to illustrate the problem of fire accidents in the Sultanate of Oman and their causes in order to find out how the existing data could be used as a base to improve fire resistance, to detect the weak points (vulnerability to fire in existing structures, and to minimize fire occurrences in places where it is high. This will also provide useful recommendations with regard to fire safety including causes, people’s awareness and education, etc.  Fire data in Oman were collected from two sources: The Directorate General of Civil Defence (Public Relations Department and Sultan Qaboos University library. The collected data represent the number of fires in Oman during the last decade.  It also includes fire distribution by type and averages.  The analysis shows that there is a linear increase in the number of fire accidents in the last decade with time.  Many factors are included as potential sources, which are explained in the paper, and suggestions are made for possible control.

  14. Repository Subsurface Preliminary Fire Hazard Analysis

    International Nuclear Information System (INIS)

    Logan, Richard C.

    2001-01-01

    This fire hazard analysis identifies preliminary design and operations features, fire, and explosion hazards, and provides a reasonable basis to establish the design requirements of fire protection systems during development and emplacement phases of the subsurface repository. This document follows the Technical Work Plan (TWP) (CRWMS M and O 2001c) which was prepared in accordance with AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''; Attachment 4 of AP-ESH-008, ''Hazards Analysis System''; and AP-3.11Q, ''Technical Reports''. The objective of this report is to establish the requirements that provide for facility nuclear safety and a proper level of personnel safety and property protection from the effects of fire and the adverse effects of fire-extinguishing agents

  15. Repository Subsurface Preliminary Fire Hazard Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Richard C. Logan

    2001-07-30

    This fire hazard analysis identifies preliminary design and operations features, fire, and explosion hazards, and provides a reasonable basis to establish the design requirements of fire protection systems during development and emplacement phases of the subsurface repository. This document follows the Technical Work Plan (TWP) (CRWMS M&O 2001c) which was prepared in accordance with AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''; Attachment 4 of AP-ESH-008, ''Hazards Analysis System''; and AP-3.11Q, ''Technical Reports''. The objective of this report is to establish the requirements that provide for facility nuclear safety and a proper level of personnel safety and property protection from the effects of fire and the adverse effects of fire-extinguishing agents.

  16. Analysis of large urban fires

    International Nuclear Information System (INIS)

    Kang, S.W.; Reitter, T.A.; Takata, A.N.

    1984-11-01

    Fires in urban areas caused by a nuclear burst are analyzed as a first step towards determining their smoke-generation chacteristics, which may have grave implications for global-scale climatic consequences. A chain of events and their component processes which would follow a nuclear attack are described. A numerical code is currently being developed to calculate ultimately the smoke production rate for a given attack scenario. Available models for most of the processes are incorporated into the code. Sample calculations of urban fire-development history performed in the code for an idealized uniform city are presented. Preliminary results indicate the importance of the wind, thermal radiation transmission, fuel distributions, and ignition thresholds on the urban fire spread characteristics. Future plans are to improve the existing models and develop new ones to characterize smoke production from large urban fires. 21 references, 18 figures

  17. Fire-accident analysis code (FIRAC) verification

    International Nuclear Information System (INIS)

    Nichols, B.D.; Gregory, W.S.; Fenton, D.L.; Smith, P.R.

    1986-01-01

    The FIRAC computer code predicts fire-induced transients in nuclear fuel cycle facility ventilation systems. FIRAC calculates simultaneously the gas-dynamic, material transport, and heat transport transients that occur in any arbitrarily connected network system subjected to a fire. The network system may include ventilation components such as filters, dampers, ducts, and blowers. These components are connected to rooms and corridors to complete the network for moving air through the facility. An experimental ventilation system has been constructed to verify FIRAC and other accident analysis codes. The design emphasizes network system characteristics and includes multiple chambers, ducts, blowers, dampers, and filters. A larger industrial heater and a commercial dust feeder are used to inject thermal energy and aerosol mass. The facility is instrumented to measure volumetric flow rate, temperature, pressure, and aerosol concentration throughout the system. Aerosol release rates and mass accumulation on filters also are measured. We have performed a series of experiments in which a known rate of thermal energy is injected into the system. We then simulated this experiment with the FIRAC code. This paper compares and discusses the gas-dynamic and heat transport data obtained from the ventilation system experiments with those predicted by the FIRAC code. The numerically predicted data generally are within 10% of the experimental data

  18. Fully coupled numerical simulation of fire in tunnels: From fire scenario to structural response

    Directory of Open Access Journals (Sweden)

    Pesavento F.

    2013-09-01

    Full Text Available In this paper we present an efficient tool for simulation of a fire scenario in a tunnel. The strategy adopted is based on a 3D-2D coupling technique between the fluid domain and the solid one. So, the thermally driven CFD part is solved in a three dimensional cavity i.e. the tunnel, and the concrete part is solved on 2D sections normal to the tunnel axis, at appropriate intervals. The heat flux and temperature values, which serve as coupling terms between the fluid and the structural problem, are interpolated between the sections. Between the solid and the fluid domain an interface layer is created for the calculation of the heat flux exchange based on a “wall law”. In the analysis of the concrete structures, concrete is treated as a multiphase porous material. Some examples of application of this fully coupled tool will be shown.

  19. Turbulence and fire-spotting effects into wild-land fire simulators

    Science.gov (United States)

    Kaur, Inderpreet; Mentrelli, Andrea; Bosseur, Frédéric; Filippi, Jean-Baptiste; Pagnini, Gianni

    2016-10-01

    This paper presents a mathematical approach to model the effects and the role of phenomena with random nature such as turbulence and fire-spotting into the existing wildfire simulators. The formulation proposes that the propagation of the fire-front is the sum of a drifting component (obtained from an existing wildfire simulator without turbulence and fire-spotting) and a random fluctuating component. The modelling of the random effects is embodied in a probability density function accounting for the fluctuations around the fire perimeter which is given by the drifting component. In past, this formulation has been applied to include these random effects into a wildfire simulator based on an Eulerian moving interface method, namely the Level Set Method (LSM), but in this paper the same formulation is adapted for a wildfire simulator based on a Lagrangian front tracking technique, namely the Discrete Event System Specification (DEVS). The main highlight of the present study is the comparison of the performance of a Lagrangian and an Eulerian moving interface method when applied to wild-land fire propagation. Simple idealised numerical experiments are used to investigate the potential applicability of the proposed formulation to DEVS and to compare its behaviour with respect to the LSM. The results show that DEVS based wildfire propagation model qualitatively improves its performance (e.g., reproducing flank and back fire, increase in fire spread due to pre-heating of the fuel by hot air and firebrands, fire propagation across no fuel zones, secondary fire generation, ...) when random effects are included according to the present formulation. The performance of DEVS and LSM based wildfire models is comparable and the only differences which arise among the two are due to the differences in the geometrical construction of the direction of propagation. Though the results presented here are devoid of any validation exercise and provide only a proof of concept, they show a

  20. Motorcoach and school bus fire safety analysis.

    Science.gov (United States)

    2016-11-01

    This report documents a motorcoach and school bus fire safety analysis performed by the John A. Volpe National Transportation Systems Center (Volpe) for the Federal Motor Carrier Safety Administration. This report aims to: 1) identify the causes, fre...

  1. Large eddy simulation based fire modeling applications for Indian nuclear power plant

    International Nuclear Information System (INIS)

    Sharma, Pavan K.; Markandeya, S.G.; Ghosh, A.K.; Kushwaha, H.S.

    2005-01-01

    Full text of publication follows: The Nuclear Power Plants (NPPs) are always designed for the highest level of safety against postulated accidents which may be initiated due to internal or external causes. One of the external/internal causes, which may lead to accident in the reactor and its associated systems, is fire in certain vital areas of the plant. Conventionally, the fire containment approach and/or the fire confinement approach is used in designing the fire protection systems of NPPs. Indian NPPs (PHWRs) follow the combined approach to ensure plant safety and all newly designed plants are required to comply with the provisions of Atomic Energy Regulatory Board (AERB) fire safety Guide. In respect of older plants, the reassessment of adequacy of fire safety provisions in the light of current advances has becomes essential so as to decide upon the steps for retrofitting. Keeping this in mind the deterministic fire hazard analysis was carried out for the Madras Atomic Power Station (MAPS). As a part of this exercise, detailed fire consequences analysis was required to be carried out for various critical areas. The choice of CFD based code was considered appropriate for these studies. A dedicated fire hazard analysis code Fire Dynamics Simulator (FDS) from NIST was used to perform these case studies. The code has option to use advanced fire models based on Large Eddy Simulation (LES) technique/ Direct Numerical Simulation (DNS) to model the fire-generated conditions. The LES option has been extensively used in the present studies which were primarily aimed at estimating the damage time for important safety related cable. Present paper describes the salient features of the methodology and important results for one of the most critical areas i.e. cable bridge area of MAPS. The typical dimensions of the cable bridge area are (length x breadth x height) of 12 m x 6 m x 2.5 m with an opening on one side of the cable bridge area. With almost equal gap, six numbers

  2. Fire spread simulation of a full scale cable tunnel

    International Nuclear Information System (INIS)

    Huhtanen, R.

    1999-11-01

    A fire simulation of a full scale tunnel was performed by using the commercial code EFFLUENT as the simulation platform. Estimation was made for fire spread on the stacked cable trays, possibility of fire spread to the cable trays on the opposite wall of the tunnel, detection time of smoke detectors in the smouldering phase and response of sprinkler heads in the flaming phase. According to the simulation, the rise of temperature in the smouldering phase is minimal, only of the order 1 deg C. The estimates of optical density of smoke show that normal smoke detectors should give an alarm within 2-4 minutes from the beginning of the smouldering phase, depending on the distance to the detector (in this case it was assumed that the thermal source connected to the smoke source was 50 W). The flow conditions at smoke detectors may be challenging, because the velocity magnitude is rather low at this phase. At 4 minutes the maximum velocity at the detectors is 0.12 m/s. During the flaming phase (beginning from 11 minutes) fire spreads on the stacked cable trays in an expected way, although the ignition criterion seems to perform poorly when ignition of new objects is considered. The Upper cable trays are forced to ignite by boundary condition definitions according to the experience found from ti full scale experiment and an earlier simulation. After 30 minutes the hot layer in the room becomes so hot that it speeds up the fire spread and the rate of heat release of burning objects. Further, the hot layer ignites the cable trays on the opposite wall of the tunnel after 45 minutes. It is estimated that the sprinkler heads would be activated at 20-22 minutes near the fire source and at 24-28 minutes little further from the fire source when fast sprinkler heads are used. The slow heads are activated between 26-32 minutes. (orig.)

  3. Fire hazards analysis of transuranic waste storage and assay facility

    Energy Technology Data Exchange (ETDEWEB)

    Busching, K.R., Westinghouse Hanford

    1996-07-31

    This document analyzes the fire hazards associated with operations at the Central Waste Complex. It provides the analysis and recommendations necessary to ensure compliance with applicable fire codes.

  4. Fire Hazard Analysis for the Cold Vacuum Drying (CVD) Facility

    International Nuclear Information System (INIS)

    JOHNSON, B.H.

    1999-01-01

    This Fire Hazard Analysis assesses the risk from fire within individual fire areas in the Cold Vacuum Drying Facility at the Hanford Site in relation to existing or proposed fire protection features to ascertain whether the objectives of DOE Order 5480.7A Fire Protection are met

  5. Fire Hazard Analysis for the Cold Vacuum Drying (CVD) Facility

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON, B.H.

    1999-08-19

    This Fire Hazard Analysis assesses the risk from fire within individual fire areas in the Cold Vacuum Drying Facility at the Hanford Site in relation to existing or proposed fire protection features to ascertain whether the objectives of DOE Order 5480.7A Fire Protection are met.

  6. Simulation of quaking aspen potential fire behavior in Northern Utah, USA

    Science.gov (United States)

    R. Justin DeRose; A. Joshua Leffler

    2014-01-01

    Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and...

  7. Fire analysis. Relevant aspects from Spanish nuclear power plants experience

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Pedro; Villar, Tomas [Empresarios Agrupados A.I.E., Madrid (Spain). Nuclear Safety Dept.

    2015-12-15

    not fall within the range of the study, further justification must be made. Additionally, in order to compare the results and to check that the semi-empirical equations described in NUREG-1805 lead to conservative results, some calculations for a few fire zones were performed using the more accurate CFD model ''Fire Dynamics Simulator'' (FDS). As a result of Human Reliability Analysis, more complete and accurate information about equipment and instrumentation that can fail due to a fire in the different fire areas will be provided to the operators in order to assure them about the equipment they can rely on in case of fire, thus helping them respond better to a plant transient caused by the fire. As part of the transition process to NFPA-805, an estimation has been performed of the increase in risk associated with non-compliance with Appendix R of 10 CFR 50, for both Core Damage Frequency (CDF) and Large Early Release Frequency (LERF), in order to determine its acceptability within the criteria established in the Regulatory Guide 1.174.

  8. Simulation and Study of Natural Fire in a Wide-Framed Multipurpose Hall with Steel Roof Trusses

    Directory of Open Access Journals (Sweden)

    D. Pada

    2009-01-01

    Full Text Available In this case study, the structural fire safety of unprotected steel roof trusses in a wide-framed multipurpose hall was evaluated according to the natural fire safety concept. The design fires were simulated with FDS in order to determine the temperature development inside the hall. The temperature of the steel was calculated based on the results from the simulation and the structural analysis was carried out in Robot. It was established that the steel roof trusses could be left unprotected under certain conditions, however, a more violent design fire resulted in failure of the truss. 

  9. Probabilistic analysis of fires in nuclear plants

    International Nuclear Information System (INIS)

    Unione, A.; Teichmann, T.

    1985-01-01

    The aim of this paper is to describe a multilevel (i.e., staged) probabilistic analysis of fire risks in nuclear plants (as part of a general PRA) which maximizes the benefits of the FRA (fire risk assessment) in a cost effective way. The approach uses several stages of screening, physical modeling of clearly dominant risk contributors, searches for direct (e.g., equipment dependences) and secondary (e.g., fire induced internal flooding) interactions, and relies on lessons learned and available data from and surrogate FRAs. The general methodology is outlined. 6 figs., 10 tabs

  10. Assessing the accuracy of wildland fire situation analysis (WFSA) fire size and suppression cost estimates.

    Science.gov (United States)

    Geoffrey H. Donovan; Peter. Noordijk

    2005-01-01

    To determine the optimal suppression strategy for escaped wildfires, federal land managers are requiredto conduct a wildland fire situation analysis (WFSA). As part of the WFSA process, fire managers estimate final fire size and suppression costs. Estimates from 58 WFSAs conducted during the 2002 fire season are compared to actual outcomes. Results indicate that...

  11. FIRES: Fire Information Retrieval and Evaluation System - A program for fire danger rating analysis

    Science.gov (United States)

    Patricia L. Andrews; Larry S. Bradshaw

    1997-01-01

    A computer program, FIRES: Fire Information Retrieval and Evaluation System, provides methods for evaluating the performance of fire danger rating indexes. The relationship between fire danger indexes and historical fire occurrence and size is examined through logistic regression and percentiles. Historical seasonal trends of fire danger and fire occurrence can be...

  12. Simulating the impacts of fire: A computer program

    Science.gov (United States)

    Ffolliott, Peter F.; Guertin, D. Phillip; Rasmussen, William D.

    1988-11-01

    Recurrent fire has played a dominant role in the ecology of southwestern ponderosa pine forests. To assess the benefits or losses of fire in these forests, a computer simulation model, called BURN, considers vegetation (mortality, regeneration, and production of herbaceous vegetation), wildlife (populations and habitats), and hydrology (streamflow and water quality). In the formulation of the model, graphical representations (time-trend response curves) of increases or losses (compared to an unburned control) after the occurrence of fire are converted to fixedterm annual ratios, and then annuities for the simulation components. Annuity values higher than 1.0 indicate benefits, while annuity values lower than 1.0 indicate losses. Studies in southwestern ponderosa pine forests utilized in the development of BURN are described briefly.

  13. Multifractal analysis of forest fires in complex regions

    Science.gov (United States)

    Vega Orozco, C. D.; Kanevski, M.; Golay, J.; Tonini, M.; Conedera, M.

    2012-04-01

    Forest fires can be studied as point processes where the ignition points represent the set of locations of the observed events in a defined study region. Their spatial and temporal patterns can be characterized by their fractal properties; which quantify the global aspect of the geometry of the support data. However, a monofractal dimension can not completely describe the pattern structure and related scaling properties. Enhancements in fractal theory had developed the multifractal concept which describes the measures from which interlinked fractal sets can be retrieved and characterized by their fractal dimension and singularity strength [1, 2]. The spatial variability of forest fires is conditioned by an intermixture of human, topographic, meteorological and vegetation factors. This heterogeneity makes fire patterns complex scale-invariant processes difficult to be depicted by a single scale. Therefore, this study proposes an exploratory data analysis through a multifractal formalism to characterize and quantify the multiscaling behaviour of the spatial distribution pattern of this phenomenon in a complex region like the Swiss Alps. The studied dataset is represented by 2,401 georeferenced forest fire ignition points in canton Ticino, Switzerland, in a 40-years period from 1969 to 2008. Three multifractal analyses are performed: one assesses the multiscaling behaviour of fire occurrence probability of the support data (raw data) and four random patterns simulated within three different support domains; second analysis studies the multifractal behavior of patterns from anthropogenic and natural ignited fires (arson-, accident- and lightning-caused fires); and third analysis aims at detecting scale-dependency of the size of burned area. To calculate the generalized dimensions, Dq, a generalization of the box counting methods is carried out based on the generalization of Rényi information of the qth order moment of the probability distribution. For q > 0, Dq

  14. Quantitative analysis of forest fire extinction efficiency

    Directory of Open Access Journals (Sweden)

    Miguel E. Castillo-Soto

    2015-08-01

    Full Text Available Aim of study: Evaluate the economic extinction efficiency of forest fires, based on the study of fire combat undertaken by aerial and terrestrial means. Area of study, materials and methods: Approximately 112,000 hectares in Chile. Records of 5,876 forest fires that occurred between 1998 and 2009 were analyzed. The area further provides a validation sector for results, by incorporating databases for the years 2010 and 2012. The criteria used for measuring extinction efficiency were economic value of forestry resources, Contraction Factor analysis and definition of the extinction costs function. Main results: It is possible to establish a relationship between burnt area, extinction costs and economic losses. The method proposed may be used and adapted to other fire situations, requiring unit costs for aerial and terrestrial operations, economic value of the property to be protected and speed attributes of fire spread in free advance. Research highlights: The determination of extinction efficiency in containment works of forest fires and potential projection of losses, different types of plant fuel and local conditions favoring the spread of fire broaden the admissible ranges of a, φ and Ce considerably.

  15. Fire hazards analysis for solid waste burial grounds

    International Nuclear Information System (INIS)

    McDonald, K.M.

    1995-01-01

    This document comprises the fire hazards analysis for the solid waste burial grounds, including TRU trenches, low-level burial grounds, radioactive mixed waste trenches, etc. It analyzes fire potential, and fire damage potential for these facilities. Fire scenarios may be utilized in future safety analysis work, or for increasing the understanding of where hazards may exist in the present operation

  16. The influence of sodium fires on LMFBRs safety analysis

    International Nuclear Information System (INIS)

    Justin, F.

    1979-01-01

    In a sodium cooled reactor, sodium fires are accidental conditions to be taken into account in safety analysis. For the various sodium categories, fire conditions, associated risks, safety analysis objectives and detailed corresponding issues are indicated, An experimental research program can be deduced from these considerations. This report covers the following: safety analysis methodology; primary sodium fires; secondary sodium fires; auxiliary sodium fires, and related experimental research programs

  17. Assessing accuracy of point fire intervals across landscapes with simulation modelling

    Science.gov (United States)

    Russell A. Parsons; Emily K. Heyerdahl; Robert E. Keane; Brigitte Dorner; Joseph Fall

    2007-01-01

    We assessed accuracy in point fire intervals using a simulation model that sampled four spatially explicit simulated fire histories. These histories varied in fire frequency and size and were simulated on a flat landscape with two forest types (dry versus mesic). We used three sampling designs (random, systematic grids, and stratified). We assessed the sensitivity of...

  18. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

    Sørensen, K.; Condra, T.; Houbak, Niels

    2003-01-01

    A model for a flue gas boiler covering the flue gas and the water-/steam side has been formulated. The model has been formulated as a number of sub models that are merged into an overall model for the complete boiler. Sub models have been defined for the furnace, the convection zone (split in 2......: a zone submerged in water and a zone covered by steam), a model for the material in the boiler (the steel) and 2 models for resp. the water/steam zone (the boiling) and the steam. The dynamic model has been developed as a number of Differential-Algebraic-Equation system (DAE). Subsequently Mat......Lab/Simulink has been applied for carrying out the simulations. To be able to verify the simulated results experiments has been carried out on a full scale boiler plant....

  19. Simulation and optimization of evacuation routes in case of fire in underground mines

    Directory of Open Access Journals (Sweden)

    Vancho Adjiski

    2015-01-01

    Full Text Available Risks of fire occurrence in underground mines are known for a long time. Evacuation and rescue plans allow to each underground mine to respond and establish control in case of emergency. The primary goal of this paper is to determine the optimal system for evacuation in case of fire in underground mines and through a process of computer simulation to be presented to all workers that are affected by this issue. In this study is developed a system that allows by using available software to work out the complete evacuation plans that include analysis of fire scenarios and optimal routes for evacuation. With development of database of fire scenarios, it is possible to plan routes for evacuation in all situations. This presented methodology can serve to make effective system for evacuation and rescue in case of fire and to help save lives and protect the financial investment in the mine. This methodology represents the most economical option of making an effective system for evacuation and also can serve as an idea of making a software package that includes all the steps of making a system for evacuation and rescue in case of fire in underground mines. This presented model will have increased accuracy compared to other models presented so far, because of the prepared 3D model of the underground mine which includes the actual dimensions of the mine along with its associated elements from which the fire dynamics and system for evacuation depends.

  20. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2003-01-01

    This paper presents an analysis of the possibilities for improving the efficiency of an indi-rectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supple-mentary firing may be based on natural gas, biogas or pyrolysis gas. Intuitively, sup-plementary firing is expected ...

  1. Evaluating the ecological benefits of wildfire by integrating fire and ecosystem simulation models

    Science.gov (United States)

    Robert E. Keane; Eva Karau

    2010-01-01

    Fire managers are now realizing that wildfires can be beneficial because they can reduce hazardous fuels and restore fire-dominated ecosystems. A software tool that assesses potential beneficial and detrimental ecological effects from wildfire would be helpful to fire management. This paper presents a simulation platform called FLEAT (Fire and Landscape Ecology...

  2. New tendencies in wildland fire simulation for understanding fire phenomena: An overview of the WFDS system capabilities in Mediterranean ecosystems

    Science.gov (United States)

    Pastor, E.; Tarragó, D.; Planas, E.

    2012-04-01

    Wildfire theoretical modeling endeavors predicting fire behavior characteristics, such as the rate of spread, the flames geometry and the energy released by the fire front by applying the physics and the chemistry laws that govern fire phenomena. Its ultimate aim is to help fire managers to improve fire prevention and suppression and hence reducing damage to population and protecting ecosystems. WFDS is a 3D computational fluid dynamics (CFD) model of a fire-driven flow. It is particularly appropriate for predicting the fire behaviour burning through the wildland-urban interface, since it is able to predict the fire behaviour in the intermix of vegetative and structural fuels that comprise the wildland urban interface. This model is not suitable for operational fire management yet due to computational costs constrains, but given the fact that it is open-source and that it has a detailed description of the fuels and of the combustion and heat transfer mechanisms it is currently a suitable system for research purposes. In this paper we present the most important characteristics of the WFDS simulation tool in terms of the models implemented, the input information required and the outputs that the simulator gives useful for understanding fire phenomena. We briefly discuss its advantages and opportunities through some simulation exercises of Mediterranean ecosystems.

  3. Using cellular automata to simulate forest fire propagation in Portugal

    Science.gov (United States)

    Freire, Joana; daCamara, Carlos

    2017-04-01

    Wildfires in the Mediterranean region have severe damaging effects mainly due to large fire events [1, 2]. When restricting to Portugal, wildfires have burned over 1:4 million ha in the last decade. Considering the increasing tendency in the extent and severity of wildfires [1, 2], the availability of modeling tools of fire episodes is of crucial importance. Two main types of mathematical models are generally available, namely deterministic and stochastic models. Deterministic models attempt a description of fires, fuel and atmosphere as multiphase continua prescribing mass, momentum and energy conservation, which typically leads to systems of coupled PDEs to be solved numerically on a grid. Simpler descriptions, such as FARSITE, neglect the interaction with atmosphere and propagate the fire front using wave techniques. One of the most important stochastic models are Cellular Automata (CA), in which space is discretized into cells, and physical quantities take on a finite set of values at each cell. The cells evolve in discrete time according to a set of transition rules, and the states of the neighboring cells. In the present work, we implement and then improve a simple and fast CA model designed to operationally simulate wildfires in Portugal. The reference CA model chosen [3] has the advantage of having been applied successfully in other Mediterranean ecosystems, namely to historical fires in Greece. The model is defined on a square grid with propagation to 8 nearest and next-nearest neighbors, where each cell is characterized by 4 possible discrete states, corresponding to burning, not-yet burned, fuel-free and completely burned cells, with 4 possible rules of evolution which take into account fuel properties, meteorological conditions, and topography. As a CA model, it offers the possibility to run a very high number of simulations in order to verify and apply the model, and is easily modified by implementing additional variables and different rules for the

  4. A Contextual Fire Detection Algorithm for Simulated HJ-1B Imagery

    Directory of Open Access Journals (Sweden)

    Xiangsheng Kong

    2009-02-01

    Full Text Available The HJ-1B satellite, which was launched on September 6, 2008, is one of the small ones placed in the constellation for disaster prediction and monitoring. HJ-1B imagery was simulated in this paper, which contains fires of various sizes and temperatures in a wide range of terrestrial biomes and climates, including RED, NIR, MIR and TIR channels. Based on the MODIS version 4 contextual algorithm and the characteristics of HJ-1B sensor, a contextual fire detection algorithm was proposed and tested using simulated HJ-1B data. It was evaluated by the probability of fire detection and false alarm as functions of fire temperature and fire area. Results indicate that when the simulated fire area is larger than 45 m2 and the simulated fire temperature is larger than 800 K, the algorithm has a higher probability of detection. But if the simulated fire area is smaller than 10 m2, only when the simulated fire temperature is larger than 900 K, may the fire be detected. For fire areas about 100 m2, the proposed algorithm has a higher detection probability than that of the MODIS product. Finally, the omission and commission error were evaluated which are important factors to affect the performance of this algorithm. It has been demonstrated that HJ-1B satellite data are much sensitive to smaller and cooler fires than MODIS or AVHRR data and the improved capabilities of HJ-1B data will offer a fine opportunity for the fire detection.

  5. WIPP fire hazards and risk analysis

    International Nuclear Information System (INIS)

    1991-05-01

    The purpose of this analysis was to conduct a fire hazards risk analysis of the Transuranic (TRU) contact-handled waste receipt, emplacement, and disposal activities at the Waste Isolation Pilot Plant (WIPP). The technical bases and safety envelope for these operations are defined in the approved WIPP Final Safety Analysis Report (FSAR). Although the safety documentation for the initial phase of the Test Program, the dry bin scale tests, has not yet been approved by the Department of Energy (DOE), reviews of the draft to date, including those by the Advisory Committee on Nuclear Facility Safety (ACNFS), have concluded that the dry bin scale tests present no significant risks in excess of those estimated in the approved WIPP FSAR. It is the opinion of the authors and reviewers of this analysis, based on sound engineering judgment and knowledge of the WIPP operations, that a Fire Hazards and Risk Analysis specific to the dry bin scale test program is not warranted prior to first waste receipt. This conclusion is further supported by the risk analysis presented in this document which demonstrates the level of risk to WIPP operations posed by fire to be extremely low. 15 refs., 41 figs., 48 tabs

  6. Fire simulation in nuclear facilities--the FIRAC code and supporting experiments

    International Nuclear Information System (INIS)

    Burkett, M.W.; Martin, R.A.; Fenton, D.L.; Gunaji, M.V.

    1985-01-01

    The fire accident analysis computer code FIRAC was designed to estimate radioactive and nonradioactive source terms and predict fire-induced flows and thermal and material transport within the ventilation systems of nuclear fuel cycle facilities. FIRAC maintains its basic structure and features and has been expanded and modified to include the capabilities of the zone-type compartment fire model computer code FIRIN developed by Battelle Pacific Northwest Laboratory. The two codes have been coupled to provide an improved simulation of a fire-induced transient within a facility. The basic material transport capability of FIRAC has been retained and includes estimates of entrainment, convection, deposition, and filtration of material. The interrelated effects of filter plugging, heat transfer, gas dynamics, material transport, and fire and radioactive source terms also can be simulated. Also, a sample calculation has been performed to illustrate some of the capabilities of the code and how a typical facility is modeled with FIRAC. In addition to the analytical work being performed at Los Alamos, experiments are being conducted at the New Mexico State University to support the FIRAC computer code development and verification. This paper summarizes two areas of the experimental work that support the material transport capabilities of the code: the plugging of high-efficiency particulate air (HEPA) filters by combustion aerosols and the transport and deposition of smoke in ventilation system ductwork

  7. Fire simulation of the canister transfer and installation vehicle; Kapselin siirto- ja asennusajoneuvon palosimulointi

    Energy Technology Data Exchange (ETDEWEB)

    Peltokorpi, L. [Fortum Power and Heat Oy, Espoo (Finland)

    2012-12-15

    A pyrolysis model of the canister transfer and installation vehicle was developed and vehicle fires in the final disposal tunnel and in the central tunnel were simulated using the fire simulation program FDS (Fire Dynamics Simulator). For comparison, same vehicle fire was also simulated at conditions in which the fire remained as a fuel controlled during the whole simulation. The purpose of the fire simulations was to simulate the fire behaviour realistically taking into account for example the limitations coming from the lack of oxygen. The material parameters for the rubber were defined and the simulation models for the tyres developed by simulating the fire test of a front wheel loader rubber tyre done by SP Technical Research Institute of Sweden. In these simulations the most important phenomena were successfully brought out but the timing of the phenomena was difficult. The final values for the rubber material parameters were chosen so that the simulated fire behaviour was at least as intense as the measured one. In the vehicle fire simulations a hydraulic oil or diesel leak causing a pool fire size of 2 MW and 2 m{sup 2} was assumed. The pool fire was assumed to be located under the tyres of the SPMT (Self Propelled Modular Transporters) transporter. In each of the vehicle fire simulations only the tyres of the SPMT transporter were observed to be burning whereas the tyres of the trailer remained untouched. In the fuel controlled fire the maximum power was slightly under 10 MW which was reached in about 18 minutes. In the final disposal tunnel the growth of the fire was limited due to the lack of oxygen and the relatively fast air flows existing in the tunnel. Fast air flows caused the flame spreading to be limited to the certain directions. In the final disposal tunnel fire the maximum power was slightly over 7 MW which was reached about 8 minutes after the ignition. In the central tunnel there was no shortage of oxygen but the spread of the fire was limited

  8. Blended-fuel based EDC combustion model and its application in heptane-ethanol fire simulation

    Directory of Open Access Journals (Sweden)

    Changjian Wang

    2014-01-01

    Full Text Available The blended-fuel based eddy-dissipation-concept combustion model was newly developed in the FireFOAM framework, and applied to simulate 30 cm×30 cm heptane-ethanol pool fire. Comparison was made of fire height, centerline temperature against experimental measurements, which shows that they match very well with each other. However, further studies are needed to examine the validation of this model in fire simulations with various scales.

  9. Fire hazards analysis for the uranium oxide (UO3) facility

    International Nuclear Information System (INIS)

    Wyatt, D.M.

    1994-01-01

    The Fire Hazards Analysis (FHA) documents the deactivation end-point status of the UO 3 complex fire hazards, fire protection and life safety systems. This FHA has been prepared for the Uranium Oxide Facility by Westinghouse Hanford Company in accordance with the criteria established in DOE 5480.7A, Fire Protection and RLID 5480.7, Fire Protection. The purpose of the Fire Hazards Analysis is to comprehensively and quantitatively assess the risk from a fire within individual fire areas in a Department of Energy facility so as to ascertain whether the objectives stated in DOE Order 5480.7, paragraph 4 are met. Particular attention has been paid to RLID 5480.7, Section 8.3, which specifies the criteria for deactivating fire protection in decommission and demolition facilities

  10. Sensitivity Analysis of a Simplified Fire Dynamic Model

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Nielsen, Anker

    2015-01-01

    This paper discusses a method for performing a sensitivity analysis of parameters used in a simplified fire model for temperature estimates in the upper smoke layer during a fire. The results from the sensitivity analysis can be used when individual parameters affecting fire safety are assessed...

  11. Simulation of Quaking Aspen Potential Fire Behavior in Northern Utah, USA

    Directory of Open Access Journals (Sweden)

    R. Justin DeRose

    2014-12-01

    Full Text Available Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and Fuels Extension. The wind speeds necessary for crowning (crown-to-crown fire spread and torching (surface to crown fire spread were evaluated to test the hypothesis that predicted fire behavior is influenced by the proportion of aspen in the stand. Results showed a strong effect of species composition on crowning, but only under moderate fire weather, where aspen-dominated stands were unlikely to crown or torch. Although rarely observed in actual fires, conifer-dominated stands were likely to crown but not to torch, an example of “hysteresis” in crown fire behavior. Results support the hypothesis that potential crown fire behavior varies across a gradient of aspen dominance and fire weather, where it was likely under extreme and severe fire weather, and unlikely under moderate and high fire weather. Furthermore, the “fire-proof” nature of aspen stands broke down across the gradient of aspen dominance and fire weather.

  12. Time fluctuation analysis of forest fire sequences

    Science.gov (United States)

    Vega Orozco, Carmen D.; Kanevski, Mikhaïl; Tonini, Marj; Golay, Jean; Pereira, Mário J. G.

    2013-04-01

    Forest fires are complex events involving both space and time fluctuations. Understanding of their dynamics and pattern distribution is of great importance in order to improve the resource allocation and support fire management actions at local and global levels. This study aims at characterizing the temporal fluctuations of forest fire sequences observed in Portugal, which is the country that holds the largest wildfire land dataset in Europe. This research applies several exploratory data analysis measures to 302,000 forest fires occurred from 1980 to 2007. The applied clustering measures are: Morisita clustering index, fractal and multifractal dimensions (box-counting), Ripley's K-function, Allan Factor, and variography. These algorithms enable a global time structural analysis describing the degree of clustering of a point pattern and defining whether the observed events occur randomly, in clusters or in a regular pattern. The considered methods are of general importance and can be used for other spatio-temporal events (i.e. crime, epidemiology, biodiversity, geomarketing, etc.). An important contribution of this research deals with the analysis and estimation of local measures of clustering that helps understanding their temporal structure. Each measure is described and executed for the raw data (forest fires geo-database) and results are compared to reference patterns generated under the null hypothesis of randomness (Poisson processes) embedded in the same time period of the raw data. This comparison enables estimating the degree of the deviation of the real data from a Poisson process. Generalizations to functional measures of these clustering methods, taking into account the phenomena, were also applied and adapted to detect time dependences in a measured variable (i.e. burned area). The time clustering of the raw data is compared several times with the Poisson processes at different thresholds of the measured function. Then, the clustering measure value

  13. The Safety Analysis of Shipborne Ammunition in Fire Environment

    Science.gov (United States)

    Ren, Junpeng; Wang, Xudong; Yue, Pengfei

    2017-12-01

    The safety of Ammunition has always been the focus of national military science and technology issues. And fire is one of the major safety threats to the ship’s ammunition storage environment, In this paper, Mk-82 shipborne aviation bomb has been taken as the study object, simulated the whole process of fire by using the FDS (Fire Detection System) software. According to the simulation results of FDS, ANSYS software was used to simulate the temperature field of Mk-82 carrier-based aviation bomb under fire environment, and the safety of aviation bomb in fire environment was analyzed. The result shows that the aviation bombs under the fire environment can occur the combustion or explosion after 70s constant cook-off, and it was a huge threat to the ship security.

  14. Thermal stress analysis of FIRE divertor

    International Nuclear Information System (INIS)

    Baxi, C.B.; Reis, E.E.; Ulrickson, M.A.; Heizenroeder, P.; Driemeyer, D.

    2003-01-01

    The fusion engineering research experiment (FIRE) device is designed for high power density and advanced physics operating modes. Due to the short distance of the divertor from the X-point, the connection lengths are short and the scrape off layer thickness is small. A relatively high peak heat flux of 25 MW/m 2 is expected on the divertor. The FIRE divertor engineering design is based on the design approaches developed for international thermonuclear experimental reactor (ITER). The geometry of the FIRE divertor consists of water cooled copper fingers and a tungsten brush armor as plasma facing material. The divertor assembly consists of modular units for remote handling. A 316 stainless steel back plate is used for support and manifolding. The backing plate is joined to the copper fingers by pins. The coolant channel diameter is 8 mm at a pitch of 14 mm. The total power flow to the outer divertor is 35 MW. Water at an inlet temperature of 30 deg.C, 1.5 MPa and a flow velocity of 10 m/s is used with two channels in series. A margin of ∼1.6 is obtained on the critical heat flux. A three dimensional thermal stress finite element (FE) analysis of this geometry was performed. Thermal hydraulic correlations derived for ITER were used to perform the thermal analysis. Design changes were implemented to reduce the stresses and temperatures to acceptable levels

  15. Forest Fire History... A Computer Method of Data Analysis

    Science.gov (United States)

    Romain M. Meese

    1973-01-01

    A series of computer programs is available to extract information from the individual Fire Reports (U.S. Forest Service Form 5100-29). The programs use a statistical technique to fit a continuous distribution to a set of sampled data. The goodness-of-fit program is applicable to data other than the fire history. Data summaries illustrate analysis of fire occurrence,...

  16. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2002-01-01

    This paper presents an analysis of the possibilities for improving the efficiency of an indirectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supplementary firing may be based on natural gas, biogas, or pyrolysis gas. {The interest in this cycle arise from a recent ...

  17. On efficiency of fire simulation realization: parallelization with greater number of computational meshes

    Science.gov (United States)

    Valasek, Lukas; Glasa, Jan

    2017-12-01

    Current fire simulation systems are capable to utilize advantages of high-performance computer (HPC) platforms available and to model fires efficiently in parallel. In this paper, efficiency of a corridor fire simulation on a HPC computer cluster is discussed. The parallel MPI version of Fire Dynamics Simulator is used for testing efficiency of selected strategies of allocation of computational resources of the cluster using a greater number of computational cores. Simulation results indicate that if the number of cores used is not equal to a multiple of the total number of cluster node cores there are allocation strategies which provide more efficient calculations.

  18. Advanced analysis of forest fire clustering

    Science.gov (United States)

    Kanevski, Mikhail; Pereira, Mario; Golay, Jean

    2017-04-01

    Analysis of point pattern clustering is an important topic in spatial statistics and for many applications: biodiversity, epidemiology, natural hazards, geomarketing, etc. There are several fundamental approaches used to quantify spatial data clustering using topological, statistical and fractal measures. In the present research, the recently introduced multi-point Morisita index (mMI) is applied to study the spatial clustering of forest fires in Portugal. The data set consists of more than 30000 fire events covering the time period from 1975 to 2013. The distribution of forest fires is very complex and highly variable in space. mMI is a multi-point extension of the classical two-point Morisita index. In essence, mMI is estimated by covering the region under study by a grid and by computing how many times more likely it is that m points selected at random will be from the same grid cell than it would be in the case of a complete random Poisson process. By changing the number of grid cells (size of the grid cells), mMI characterizes the scaling properties of spatial clustering. From mMI, the data intrinsic dimension (fractal dimension) of the point distribution can be estimated as well. In this study, the mMI of forest fires is compared with the mMI of random patterns (RPs) generated within the validity domain defined as the forest area of Portugal. It turns out that the forest fires are highly clustered inside the validity domain in comparison with the RPs. Moreover, they demonstrate different scaling properties at different spatial scales. The results obtained from the mMI analysis are also compared with those of fractal measures of clustering - box counting and sand box counting approaches. REFERENCES Golay J., Kanevski M., Vega Orozco C., Leuenberger M., 2014: The multipoint Morisita index for the analysis of spatial patterns. Physica A, 406, 191-202. Golay J., Kanevski M. 2015: A new estimator of intrinsic dimension based on the multipoint Morisita index

  19. “Use of fire extinguishers”—a new course with a new simulator

    CERN Multimedia

    HSE Unit & GS/FB

    2012-01-01

    Don’t wait, sign up! A new training course, “Handling of fire extinguishers”, is available since the beginning of March 2012. The training course is given by members of CERN’s Fire Brigade (GS-FB) and is intended for all members of personnel of CERN. Upon successful completion of the training course, you will be able to do the following: recognise a potentially combustible item and the various fire classes; choose the appropriate extinguisher for a given fire class; handle a fire extinguisher properly and efficiently; apply CERN's safety instructions. An important part of the training are the different firefighting exercises conducted using a new simulator, which makes it possible to simulate real conditions such as the following: a fire in the office; a fire in an electrical cabinet; a fire involving chemicals.        Don’t wait:  sign up for the training course directly ...

  20. Fire debris analysis for forensic fire investigation using laser induced breakdown spectroscopy (LIBS)

    Science.gov (United States)

    Choi, Soojin; Yoh, Jack J.

    2017-08-01

    The possibility verification of the first attempt to apply LIBS to arson investigation was performed. LIBS has capabilities for real time in-situ analysis and depth profiling. It can provide valuable information about the fire debris that are complementary to the classification of original sample components and combustion residues. In this study, fire debris was analyzed to determine the ignition source and existence of a fire accelerant using LIBS spectra and depth profiling analysis. Fire debris chemical composition and carbon layer thickness determines the possible ignition source while the carbon layer thickness of combusted samples represents the degree of sample carbonization. When a sample is combusted with fire accelerants, a thicker carbon layer is formed because the burning rate is increased. Therefore, depth profiling can confirm the existence of combustion accelerants, which is evidence of arson. Also investigation of fire debris by depth profiling is still possible when a fire is extinguished with water from fire hose. Such data analysis and in-situ detection of forensic signals via the LIBS may assist fire investigation at crime scenes.

  1. Experimental measurement of a shipboard fire environment with simulated radioactive materials packages

    International Nuclear Information System (INIS)

    Koski, J.A.; Wix, S.D.

    1996-01-01

    Results from a series of eight test fires ranging in size from 2.2 to 18.8 MW conducted aboard the Coast Guard fire test ship Mayo Lykes at Mobile, Alabama are presented and discussed. Tests aboard the break-bulk type cargo ship consisted of heptane spray fires simulating engine room and galley fires, wood crib fires simulating cargo hold fires, and pool fires staged for comparison to land-based regulatory fire results. Primary instrumentation for the tests consisted of two pipe calorimeters that simulated a typical package shape for radioactive materials packages. The calorimeters were both located adjacent to the fires and on the opposite side of the cargo hold bulkhead nearest the fire. The calorimeters were constructed from 1.5 m length sections of nominal 2 foot diameter schedule 60 steel pipe. Type K thermocouples were attached at 12 locations on the circumference and ends of the calorimeter. Fire heat fluxes to the calorimeter surfaces were estimated with the use of the Sandia SODDIT inverse heat conduction code. Experimental results from all types of tests are discussed, and some comparisons are made between the environments found on the ship and those found in land-based pool fire tests

  2. An overview of the fire and fuels extension to the forest vegetation simulator

    Science.gov (United States)

    Sarah J. Beukema; Elizabeth D. Reinhardt; Werner A. Kurz; Nicholas L. Crookston

    2000-01-01

    The Fire and Fuels Extension (FFE) to the Forest Vegetation Simulator (FVS) has been developed to assess the risk, behavior, and impact of fire in forest ecosystems. This extension to the widely-used stand-dynamics model FVS simulates the dynamics of snags and surface fuels as they are affected by stand management (of trees or fuels), live tree growth and mortality,...

  3. Spatially explicit and stochastic simulation of forest landscape fire disturbance and succession

    Science.gov (United States)

    Hong S. He; David J. Mladenoff

    1999-01-01

    Understanding disturbance and recovery of forest landscapes is a challenge because of complex interactions over a range of temporal and spatial scales. Landscape simulation models offer an approach to studying such systems at broad scales. Fire can be simulated spatially using mechanistic or stochastic approaches. We describe the fire module in a spatially explicit,...

  4. Validation and uncertainty quantification of Fuego simulations of calorimeter heating in a wind-driven hydrocarbon pool fire.

    Energy Technology Data Exchange (ETDEWEB)

    Domino, Stefan Paul; Figueroa, Victor G.; Romero, Vicente Jose; Glaze, David Jason; Sherman, Martin P.; Luketa-Hanlin, Anay Josephine

    2009-12-01

    The objective of this work is to perform an uncertainty quantification (UQ) and model validation analysis of simulations of tests in the cross-wind test facility (XTF) at Sandia National Laboratories. In these tests, a calorimeter was subjected to a fire and the thermal response was measured via thermocouples. The UQ and validation analysis pertains to the experimental and predicted thermal response of the calorimeter. The calculations were performed using Sierra/Fuego/Syrinx/Calore, an Advanced Simulation and Computing (ASC) code capable of predicting object thermal response to a fire environment. Based on the validation results at eight diversely representative TC locations on the calorimeter the predicted calorimeter temperatures effectively bound the experimental temperatures. This post-validates Sandia's first integrated use of fire modeling with thermal response modeling and associated uncertainty estimates in an abnormal-thermal QMU analysis.

  5. Survival analysis and classification methods for forest fire size.

    Directory of Open Access Journals (Sweden)

    Pier-Olivier Tremblay

    Full Text Available Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene and the size at "being held" (a state when no further increase in size is expected. We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at "being held" exceeds the size at initial assessment. Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances.

  6. Survival analysis and classification methods for forest fire size.

    Science.gov (United States)

    Tremblay, Pier-Olivier; Duchesne, Thierry; Cumming, Steven G

    2018-01-01

    Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene) and the size at "being held" (a state when no further increase in size is expected). We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at "being held" exceeds the size at initial assessment). Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances.

  7. Computer simulation of forest fire and its possible usage

    International Nuclear Information System (INIS)

    Halada, L.; Weisenpacher, P.; Glasa, J.

    2005-01-01

    In this presentation authors deal with computer modelling of forest fires. Their possible usage is discussed. Results of modelling are compared with real forest fire in the National Park Slovensky Raj (Slovak Paradise) in 2000 year

  8. Advanced analysis and design for fire safety of steel structures

    CERN Document Server

    Li, Guoqiang

    2013-01-01

    Advanced Analysis and Design for Fire Safety of Steel Structures systematically presents the latest findings on behaviours of steel structural components in a fire, such as the catenary actions of restrained steel beams, the design methods for restrained steel columns, and the membrane actions of concrete floor slabs with steel decks. Using a systematic description of structural fire safety engineering principles, the authors illustrate the important difference between behaviours of an isolated structural element and the restrained component in a complete structure under fire conditions. The book will be an essential resource for structural engineers who wish to improve their understanding of steel buildings exposed to fires. It is also an ideal textbook for introductory courses in fire safety for master’s degree programs in structural engineering, and is excellent reading material for final-year undergraduate students in civil engineering and fire safety engineering. Furthermore, it successfully bridges th...

  9. Root cause analysis for fire events at nuclear power plants

    International Nuclear Information System (INIS)

    1999-09-01

    Fire hazard has been identified as a major contributor to a plant' operational safety risk. The International nuclear power community (regulators, operators, designers) has been studying and developing tools for defending against this hazed. Considerable advances have been achieved during past two decades in design and regulatory requirements for fire safety, fire protection technology and related analytical techniques. The IAEA endeavours to provide assistance to Member States in improving fire safety in nuclear power plants. A task was launched by IAEA in 1993 with the purpose to develop guidelines and good practices, to promote advanced fire safety assessment techniques, to exchange state of the art information, and to provide engineering safety advisory services and training in the implementation of internationally accepted practices. This TECDOC addresses a systematic assessment of fire events using the root cause analysis methodology, which is recognized as an important element of fire safety assessment

  10. Fire Hazards Analysis for the 200 Area Interim Storage Area

    International Nuclear Information System (INIS)

    JOHNSON, D.M.

    2000-01-01

    This documents the Fire Hazards Analysis (FHA) for the 200 Area Interim Storage Area. The Interim Storage Cask, Rad-Vault, and NAC-1 Cask are analyzed for fire hazards and the 200 Area Interim Storage Area is assessed according to HNF-PRO-350 and the objectives of DOE Order 5480 7A. This FHA addresses the potential fire hazards associated with the Interim Storage Area (ISA) facility in accordance with the requirements of DOE Order 5480 7A. It is intended to assess the risk from fire to ensure there are no undue fire hazards to site personnel and the public and to ensure property damage potential from fire is within acceptable limits. This FHA will be in the form of a graded approach commensurate with the complexity of the structure or area and the associated fire hazards

  11. 327 Building fire hazards analysis implementation plan

    International Nuclear Information System (INIS)

    Eggen, C.D.

    1998-01-01

    In March 1998, the 327 Building Fire Hazards Analysis (FRA) (Reference 1) was approved by the US Department of Energy, Richland Operations Office (DOE-RL) for implementation by B and W Hanford Company (B and WHC). The purpose of the FHA was to identify gaps in compliance with DOE Order 5480.7A (Reference 2) and Richland Operations Office Implementation Directive (RLID) 5480.7 (Reference 3), especially in regard to loss limitation. The FHA identified compliance gaps in five areas and provided nine recommendations (11 items) to bring the 327 Building into compliance. To date, actions for five of the 11 items have been completed. Exemption requests will be transmitted to DOE-RL for two of the items. Corrective actions have been identified for the remaining four items. The completed actions address combustible loading requirements associated with the operation of the cells and support areas. The status of the recommendations and actions was confirmed during the July 1998 Fire Protection Assessment. B and WHC will use this Implementation Plan to bring the 327 Building and its operation into compliance with DOE Order 5480.7A and RLID 5480.7

  12. 324 Building fire hazards analysis implementation plan

    International Nuclear Information System (INIS)

    Eggen, C.D.

    1998-01-01

    In March 1998, the 324 Building Fire Hazards Analysis (FHA) (Reference 1) was approved by the US Department of Energy, Richland Operations Office (DOE-RL) for implementation by B and W Hanford Company (BWHC). The purpose of the FHA was to identify gaps in compliance with DOE Order 5480.7A (Reference 2) and Richland Operations Office Implementation Directive (RLID) 5480.7 (Reference 3), especially in regard to loss limitation. The FHA identified compliance gaps in six areas and provided 20 recommendations to bring the 324 Building into compliance with DOE Order 5480.7A. Additionally, one observation was provided. To date, four of the recommendations and the one observation have been completed. Actions identified for seven of the recommendations are currently in progress. Exemption requests will be transmitted to DOE-RL for three of the recommendations. Six of the recommendations are related to future shut down activities of the facility and the corrective actions are not being addressed as part of this plan. The actions for recommendations associated with the safety related part of the 324 Building and operation of the cells and support areas were evaluated using the Unreviewed Safety Question (USQ) process. Major Life Safety Code concerns have been corrected. The status of the recommendations and actions was confirmed during the July 1998 Fire Protection Assessment. BVMC will use this Implementation Plan to bring the 324 Building and its operation into compliance with DOE Order 5480.7A and RLID 5480.7

  13. Surface Accessibility with Spatial Analysis During Fire Extinguishing Procedures: Example on the Island of Vis

    Directory of Open Access Journals (Sweden)

    Kruno Lepoglavec

    2017-01-01

    Full Text Available Background and Purpose: The existing public and forest transport infrastructure (truck forest roads are permanent objects used when passing through forests. They also serve as a firefighter belt and provide direct access to firefighting vehicles, or are used as the starting point where firefighting teams extinguish fires or move toward remote fires. The paper identifies the existing fire road network (including public roads, forest roads, non-classified roads and fire roads for access of firefighting vehicles during fire extinguishing interventions. Material and Methods: An analysis of the intervention rate was conducted on a dispersive sample (35 positions from two volunteer fire associations (VFA on the island of Vis. Also, an analysis of the surface availability to fire vehicles concerning the time of departure from the fire station was conducted, as well as the comparison with the Standard time of intervention defined by the regulations on fire department organization in the Republic of Croatia. Results: For each simulated fire location for intervention of two existing volunteer fire associations: VFA Komiža and VFA Vis, results show that for a few fire locations, despite a smaller distance from the VFA Komiža, a quicker intervention is possible from the VFA Vis (locations 4, 5 and 14, and vice versa (locations 21, 22 and 25. With the use of a New Service Area, tool intervention times regarding different areas were calculated. Intervention times were divided into intervals: 25 min. The last two categories of area are beyond reach for firefighters within the Standard time of intervention (15 min and together they comprise to 27.88% of the total research area. Conclusions: The results of Closest Facility tool indicate that for the simulated fire position the best/fastest route is not always the shortest one, because of a significant effect of the structural elements of each road, the state of the road and the longitudinal slope of the road

  14. 327 Building fire hazards analysis implementation plan

    International Nuclear Information System (INIS)

    BARILO, N.F.

    1999-01-01

    In March 1998, the 327 Building Fire Hazards Analysis (FHA) (Reference 1) was approved by the U.S. Department of Energy, Richland Operations Office (DOE-E) for implementation by B and W Hanford Company (BWC). The purpose of the FHA was to identify gaps in compliance with DOE Order 5480.7A (Reference 2) and Richland Operations Office Implementation Directive (RLID) 5480.7 (Reference 3), especially in regard to loss limitation. The FHA identified compliance gaps in five areas and provided nine recommendations (11 items) to bring the 327 Building into compliance. A status is provided for each recommendation in this document. BWHC will use this Implementation Plan to bring the 327 Building and its operation into compliance with DOE Order 5480.7A and IUD 5480.7

  15. Measurements and simulation for design optimization for low NOx coal-firing system

    Energy Technology Data Exchange (ETDEWEB)

    E. Bar-Ziv; Y. Yasur; B. Chudnovsky; L. Levin; A. Talanker [Ben-Gurion University of Negev, Beer-Sheva (Israel)

    2003-07-01

    The information required to design a utility steam generator is the heat balance, fuel analysis and emission. These establish the furnace wall configuration, the heat release rates, and the firing technology. The furnace must be sized for (1) residence time for complete combustion with low NOx, and (2) reduction of flue gas temperature to minimize ash deposition. To meet these, computational fluid dynamics (CFD) of the combustion process in the furnace were performed and proven to be a powerful tool for this purpose. Still, reliable numerical simulations require careful interpretation and comparison with measurements. We report numerical results and measurements for a 575 MW pulverized coal tangential firing boiler of the Hadera power plant of Israel Electric Corporation (IEC). Measured and calculated values were found to be in reasonable agreement. We used the simulations for optimization and investigated temperature distribution, heat fluxes and concentration of chemical species. We optimized both the furnace flue gas temperature entering the convective path and the staged residence time for low NOx. We tested mass flow rates through close-coupled and separate overfire air ports and its arrangement and the coal powder fineness. These parameters can control the mixing rate between the fuel and the oxidizer streams and can affect the most important characteristics of the boiler such as temperature regimes, coal burning rate and nitrogen oxidation/reduction. From this effort, IEC started to improve the boiler performance by replacing the existing typical tangential burners to low NOx firing system to ensure the current regulation requirements of emission pollutions.

  16. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2003-01-01

    This paper presents an analysis of the possibilities for improving the efficiency of an indi-rectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supple-mentary firing may be based on natural gas, biogas or pyrolysis gas. Intuitively, sup-plementary firing is expected...... to result in a high marginal efficiency. The paper shows that depending on the application, this is not always the case. The interest in this cycle arises from a recent demonstration of the feasibility of a two-stage gasification process through construction of several plants. The gas from this process...... could be divided into two streams, one for primary and one for supplementary firing. A preliminary analysis of the ideal, recuperated Brayton cycle shows that for this cycle any supplementary firing will have a marginal efficiency of unity per extra unit of fuel. The same result is obtained...

  17. Water Quality Analysis Simulation

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Water Quality analysis simulation Program, an enhancement of the original WASP. This model helps users interpret and predict water quality responses to natural...

  18. Water Quality Analysis Simulation

    Science.gov (United States)

    The Water Quality analysis simulation Program, an enhancement of the original WASP. This model helps users interpret and predict water quality responses to natural phenomena and man-made pollution for variious pollution management decisions.

  19. Surface Fire Hazards Analysis Technical Report-Constructor Facilities

    International Nuclear Information System (INIS)

    Flye, R.E.

    2000-01-01

    The purpose of this Fire Hazards Analysis Technical Report (hereinafter referred to as Technical Report) is to assess the risk from fire within individual fire areas to ascertain whether the U.S. Department of Energy (DOE) fire safety objectives are met. The objectives identified in DOE Order 420.1, Change 2, Facility Safety, Section 4.2, establish requirements for a comprehensive fire and related hazards protection program for facilities sufficient to minimize the potential for: The occurrence of a fire or related event; A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees, the public, or the environment; Vital DOE programs suffering unacceptable interruptions as a result of fire and related hazards; Property losses from a fire and related events exceeding defined limits established by DOE; and Critical process controls and safety class systems being damaged as a result of a fire and related events

  20. Rocky Flats Plant Live-Fire Range Risk Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Nicolosi, S.L.; Rodriguez, M.A.

    1994-04-01

    The objective of the Live-Fire Range Risk Analysis Report (RAR) is to provide an authorization basis for operation as required by DOE 5480.16. The existing Live-Fire Range does not have a safety analysis-related authorization basis. EG&G Rocky Flats, Inc. has worked with DOE and its representatives to develop a format and content description for development of an RAR for the Live-Fire Range. Development of the RAR is closely aligned with development of the design for a baffle system to control risks from errant projectiles. DOE 5480.16 requires either an RAR or a safety analysis report (SAR) for live-fire ranges. An RAR rather than a SAR was selected in order to gain flexibility to more closely address the safety analysis and conduct of operation needs for a live-fire range in a cost-effective manner.

  1. Estimation of time to rupture in a fire using 6FIRE, a lumped parameter UF6 cylinder transient heat transfer/stress analysis model

    International Nuclear Information System (INIS)

    Williams, W.R.; Anderson, J.C.

    1995-01-01

    The transportation of UF 6 is subject to regulations requiring the evaluation of packaging under a sequence of hypothetical accident conditions including exposure to a 30-min 800 degree C (1475 degree F) fire [10 CFR 71.73(c)(3)]. An issue of continuing interest is whether bare cylinders can withstand such a fire without rupturing. To address this issue, a lumped parameter heat transfer/stress analysis model (6FIRE) has been developed to simulate heating to the point of rupture of a cylinder containing UF 6 when it is exposed to a fire. The model is described, then estimates of time to rupture are presented for various cylinder types, fire temperatures, and fill conditions. An assessment of the quantity of UF 6 released from containment after rupture is also presented. Further documentation of the model is referenced

  2. CFD simulation of coal and straw co-firing

    DEFF Research Database (Denmark)

    Junker, Helle; Hvid, Søren L.; Larsen, Ejvind

    This paper presents the results of a major R&D program with the objective to develop CFD based tools to assess the impact of biomass co-firing in suspension fired pulverized coal power plants. The models have been developed through a series of Danish research projects with the overall objective...... emissions. Results are presented for a Danish full-scale boiler that is currently co-firing biomass with coal on a commercial basis....

  3. Clinimetric quality of the fire fighting simulation test as part of the Dutch fire fighters Workers' Health Surveillance

    Directory of Open Access Journals (Sweden)

    Sluiter Judith K

    2010-02-01

    Full Text Available Abstract Background Clinimetric data for the fire fighting simulation test (FFST, a new test proposed for the Workers' Health Surveillance (WHS of Dutch fire fighters, were evaluated. Methods Twenty-one fire fighters took the FFST three times with one and three weeks between testing. Clinimetric quality was determined by means of reliability, agreement and validity. For reliability and agreement, the intraclass correlation coefficient (ICC, and standard error of measurement (SEM, were analysed. For construct validity, the tests from 45 fire fighters were correlated with their own and their supervisors' rated work ability. Results The ICCs were 0.56 and 0.79 at the one-week and three-week test-retest periods, respectively. Testing times ranged from 9 to 17 minutes; the SEMs were 70 s at the one-week and 40 s at the three-week test-retest periods. The construct validity was moderate (-0.47 ≤ r ≤ -0.33; p Conclusions The FFST was reliable with acceptable agreement after three weeks. Construct validity was moderate. We recommend using FFST as a part of the WHS for Dutch fire fighters. It is advised that fire fighters should perform the FFST once as a trial before judging their performance in testing time during the second performance.

  4. Simulating Changes in Fires and Ecology of the 21st Century Eurasian Boreal Forests of Siberia

    Directory of Open Access Journals (Sweden)

    Ksenia Brazhnik

    2017-02-01

    Full Text Available Wildfires release the greatest amount of carbon into the atmosphere compared to other forest disturbances. To understand how current and potential future fire regimes may affect the role of the Eurasian boreal forest in the global carbon cycle, we employed a new, spatially-explicit fire module DISTURB-F (DISTURBance-Fire in tandem with a spatially-explicit, individually-based gap dynamics model SIBBORK (SIBerian BOReal forest simulator calibrated to Krasnoyarsk Region. DISTURB-F simulates the effect of forest fire on the boreal ecosystem, namely the mortality of all or only the susceptible trees (loss of biomass, i.e., carbon within the forested landscape. The fire module captures some important feedbacks between climate, fire and vegetation structure. We investigated the potential climate-driven changes in the fire regime and vegetation in middle and south taiga in central Siberia, a region with extensive boreal forest and rapidly changing climate. The output from this coupled simulation can be used to estimate carbon losses from the ecosystem as a result of fires of different sizes and intensities over the course of secondary succession (decades to centuries. Furthermore, it may be used to assess the post-fire carbon storage capacity of potential future forests, the structure and composition of which may differ significantly from current Eurasian boreal forests due to regeneration under a different climate.

  5. Applying Open Source Game Engine for Building Visual Simulation Training System of Fire Fighting

    Science.gov (United States)

    Yuan, Diping; Jin, Xuesheng; Zhang, Jin; Han, Dong

    There's a growing need for fire departments to adopt a safe and fair method of training to ensure that the firefighting commander is in a position to manage a fire incident. Visual simulation training systems, with their ability to replicate and interact with virtual fire scenarios through the use of computer graphics or VR, become an effective and efficient method for fire ground education. This paper describes the system architecture and functions of a visual simulated training system of fire fighting on oil storage, which adopting Delat3D, a open source game and simulation engine, to provide realistic 3D views. It presents that using open source technology provides not only the commercial-level 3D effects but also a great reduction of cost.

  6. Parametric analysis of fire model CFAST

    International Nuclear Information System (INIS)

    Lee, Y. H.; Yang, J. Y.; Kim, J. H.

    2004-01-01

    This paper describes the pump room fire of the nuclear power plant using CFAST fire modeling code developed by NIST. It is determined by the constrained or unconstrained fire, Lower Oxygen Limit (LOL), Radiative Fraction (RF), and the times to open doors, which are the input parameters of CAFST. According to the results, pump room fire is ventilation-controlled fire, so it is adequate that the value of LOL is 10% which is also the default value. It is appeared that the RF does not change the temperature of the upper gas layer. But the level of opening of the penetrating area and the times to opening it have an effect on the temperature of the upper layer, so it is determined that the results of it should be carefully analyzed

  7. Forecasting wildland fire behavior using high-resolution large-eddy simulations

    Science.gov (United States)

    Munoz-Esparza, D.; Kosovic, B.; Jimenez, P. A.; Anderson, A.; DeCastro, A.; Brown, B.

    2017-12-01

    Wildland fires are responsible for large socio-economic impacts. Fires affect the environment, damage structures, threaten lives, cause health issues, and involve large suppression costs. These impacts can be mitigated via accurate fire spread forecast to inform the incident management team. To this end, the state of Colorado is funding the development of the Colorado Fire Prediction System (CO-FPS). The system is based on the Weather Research and Forecasting (WRF) model enhanced with a fire behavior module (WRF-Fire). Realistic representation of wildland fire behavior requires explicit representation of small scale weather phenomena to properly account for coupled atmosphere-wildfire interactions. Moreover, transport and dispersion of biomass burning emissions from wildfires is controlled by turbulent processes in the atmospheric boundary layer, which are difficult to parameterize and typically lead to large errors when simplified source estimation and injection height methods are used. Therefore, we utilize turbulence-resolving large-eddy simulations at a resolution of 111 m to forecast fire spread and smoke distribution using a coupled atmosphere-wildfire model. This presentation will describe our improvements to the level-set based fire-spread algorithm in WRF-Fire and an evaluation of the operational system using 12 wildfire events that occurred in Colorado in 2016, as well as other historical fires. In addition, the benefits of explicit representation of turbulence for smoke transport and dispersion will be demonstrated.

  8. Nonlinear phased analysis of reinforced concrete tunnels under fire exposure

    NARCIS (Netherlands)

    Lilliu, G.; Meda, A.

    2013-01-01

    Fire analysis of precast segmental tunnels involves several problems, mainly related to the soil-structure interaction during fire exposure, coupled with material degradation. Temperature increase in the tunnel is the cause of thermal expansion of the lining, which is resisted by the soil pressure.

  9. Spatial interpolation and simulation of post-burn duff thickness after prescribed fire

    Science.gov (United States)

    Peter R. Robichaud; S. M. Miller

    1999-01-01

    Prescribed fire is used as a site treatment after timber harvesting. These fires result in spatial patterns with some portions consuming all of the forest floor material (duff) and others consuming little. Prior to the burn, spatial sampling of duff thickness and duff water content can be used to generate geostatistical spatial simulations of these characteristics....

  10. Thermal analysis of regulatory fire conditions on a transport package for radioactive material

    International Nuclear Information System (INIS)

    Ramsay, J.

    2006-01-01

    MDS Nordion, a division of Canadian-based MDS Inc., maintains and operates transport packages for the distribution of radioactive materials used in the medical, sterilization and pharmaceutical industries. Each of these packages must be proven to meet international regulatory standards, often including the analysis of the packages under accident fire conditions. Actual physical fire tests are costly and time consuming. Therefore, it is beneficial to simulate such fire tests with numerical models validated against previous tests. This paper describes the thermal simulation of the IAEA TS-R-1 regulatory fire conditions (800 o C fire for a period of 30 minutes and left to cool naturally in the heat of the sun) on a transport package using the ANSYS finite element code. The analyzed transport package is a steel-encased cylindrical lead-filled radiation shield welded to a support frame. A cylindrical cavity in the center of the shield, sealed by a lead-filled shielding plug, holds the radioactive material. The radiation shield is wrapped in thermal insulation, which is held in place by wire mesh. A two-dimensional, axi-symmetric model was developed to simulate the thermal behavior of the transport package during and after the regulatory fire. Mechanical deformations and stresses induced from the temperature distributions in the package are not considered in this paper. The mesh (solid model, radiation enclosure calculations, convection and radiation elements), material properties (non-linear), boundary conditions (radiation and convection) and loading (thermal transient, heat generation) used in the ANSYS simulations are discussed. Test data from physical steady state and transient fire tests was used to develop and validate the model. The finite element model was then used to predict and evaluate the response of the package to the TS-R-1 fire transient. (author)

  11. Analysis of the chemical composition of ultrafine particles from two domestic solid biomass fired room heaters under simulated real-world use

    Science.gov (United States)

    Ozgen, Senem; Becagli, Silvia; Bernardoni, Vera; Caserini, Stefano; Caruso, Donatella; Corbella, Lorenza; Dell'Acqua, Manuela; Fermo, Paola; Gonzalez, Raquel; Lonati, Giovanni; Signorini, Stefano; Tardivo, Ruggero; Tosi, Elisa; Valli, Gianluigi; Vecchi, Roberta; Marinovich, Marina

    2017-02-01

    Two common types of wood (beech and fir) were burned in commercial pellet (11.1 kW) and wood (8.2 kW) stoves following a combustion cycle simulating the behavior of a real-world user. Ultrafine particulate matter (UFP, dp metals, main water soluble ions, anhydrosugars, total carbon, and PAH content. The measurement of the number concentration and size distribution was also performed by a fourth multistage impactor. UFP mass emission factors averaged to 424 mg/kgfuel for all the tested stove and wood type (fir, beech) combinations except for beech log burning in the wood stove (838 mg/kgfuel). Compositional differences were observed for pellets and wood UFP samples, where high TC levels characterize the wood log combustion and potassium salts are dominant in every pellet sample. Crucial aspects determining the UFP composition in the wood stove experiments are critical situations in terms of available oxygen (a lack or an excess of combustion air) and high temperatures. Whereas for the automatically controlled pellets stove local situations (e.g., hindered air-fuel mixing due to heaps of pellets on the burner pot) determine the emission levels and composition. Wood samples contain more potentially carcinogenic PAHs with respect to pellets samples. Some diagnostic ratios related to PAH isomers and anhydrosugars compiled from experimental UFP data in the present study and compared to literature values proposed for the emission source discrimination for atmospheric aerosol, extend the evaluation usually limited to higher particle size fractions also to UFP.

  12. Material Analysis for a Fire Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Alexander; Nemer, Martin B.

    2014-08-01

    This report consolidates technical information on several materials and material classes for a fire assessment. The materials include three polymeric materials, wood, and hydraulic oil. The polymers are polystyrene, polyurethane, and melamine- formaldehyde foams. Samples of two of the specific materials were tested for their behavior in a fire - like environment. Test data and the methods used to test the materials are presented. Much of the remaining data are taken from a literature survey. This report serves as a reference source of properties necessary to predict the behavior of these materials in a fire.

  13. Application of wildfire simulation methods to assess wildfire exposure in a Mediterranean fire-prone area (Sardinia, Italy)

    Science.gov (United States)

    Salis, M.; Ager, A.; Arca, B.; Finney, M.; Bacciu, V. M.; Spano, D.; Duce, P.

    2012-12-01

    Spatial and temporal patterns of fire spread and behavior are dependent on interactions among climate, topography, vegetation and fire suppression efforts (Pyne et al. 1996; Viegas 2006; Falk et al. 2007). Humans also play a key role in determining frequency and spatial distribution of ignitions (Bar Massada et al, 2011), and thus influence fire regimes as well. The growing incidence of catastrophic wildfires has led to substantial losses for important ecological and human values within many areas of the Mediterranean basin (Moreno et al. 1998; Mouillot et al. 2005; Viegas et al. 2006a; Riaño et al. 2007). The growing fire risk issue has led to many new programs and policies of fuel management and risk mitigation by environmental and fire agencies. However, risk-based methodologies to help identify areas characterized by high potential losses and prioritize fuel management have been lacking for the region. Formal risk assessment requires the joint consideration of likelihood, intensity, and susceptibility, the product of which estimates the chance of a specific loss (Brillinger 2003; Society of Risk Analysis, 2006). Quantifying fire risk therefore requires estimates of a) the probability of a specific location burning at a specific intensity and location, and b) the resulting change in financial or ecological value (Finney 2005; Scott 2006). When large fires are the primary cause of damage, the application of this risk formulation requires modeling fire spread to capture landscape properties that affect burn probability. Recently, the incorporation of large fire spread into risk assessment systems has become feasible with the development of high performance fire simulation systems (Finney et al. 2011) that permit the simulation of hundreds of thousands of fires to generate fine scale maps of burn probability, flame length, and fire size, while considering the combined effects of weather, fuels, and topography (Finney 2002; Andrews et al. 2007; Ager and Finney 2009

  14. The FIRAC code - its applicability and boundary conditions for fire accident analysis in a reprocessing plant

    International Nuclear Information System (INIS)

    Roewekamp, M.

    1991-01-01

    After a short description of the modelling capabilities and the implementation of the computer code the possible applications of FIRAC are demonstrated by means of two test-examples. The so gained experiences with respect to the variation of different parameters, convergency criteria, etc. can be used for the simulation of a fire accident in the storage area for unconditioned combustible low active waste (LAW) of the planned reprocessing plant at Wackersdorf. The code is prepared for calculating direct effects (of the fire) in the fire room as well as particularly effects on adjacent rooms and ventilation systems. Source terms for the release of radioactive particles outside a building can also be investigated. The temperature and pressure curves for the fire room as well as for other areas in the facility show that no damages caused by temperature effects are expected for the considered fire of low active waste. As a result of the calculated mass and volumetric flows radioactive aerosole particles could be transported into normally non-active areas. The FIRAC code renders the possibility of a more detailed analysis of those parameters relevant for fire accidents and by this means completes the so far phenomenological procedure of the fire hazard analysis in nuclear facilities. (orig.) [de

  15. Fire Risk Analysis and Optimization of Fire Prevention Management for Green Building Design and High Rise Buildings: Hong Kong Experience

    Directory of Open Access Journals (Sweden)

    Yau Albert

    2014-12-01

    Full Text Available There are many iconic high rise buildings in Hong Kong, for example, International Commercial Centre, International Financial Centre, etc. Fire safety issue in high rise buildings has been raised by local fire professionals in terms of occupant evacuation, means of fire-fighting by fire fighters, sprinkler systems to automatically put off fires in buildings, etc. Fire risk becomes an important issue in building fire safety because it relates to life safety of building occupants where they live and work in high rise buildings in Hong Kong. The aim of this research is to identify the fire risk for different types of high rise buildings in Hong Kong and to optimise the fire prevention management for those high rise buildings with higher level of fire risk and to validate the model and also to carry out the study of the conflict between the current fire safety building code and the current trend of green building design. Survey via the 7-point scale questionnaire was conducted through 50 participants and their responses were received and analysed via the statistical tool SPSS software computer program. A number of statistical methods of testing for significantly difference in samples were adopted to carry out the analysis of the data received. When the statistical analysis was completed, the results of the data analysis were validated by two Fire Safety Experts in this area of specialisation and also by quantitative fire risk analysis.

  16. Energy Analysis of a Biomass Co-firing Based Pulverized Coal Power Generation System

    Directory of Open Access Journals (Sweden)

    Marc A. Rosen

    2012-03-01

    Full Text Available The results are reported of an energy analysis of a biomass/coal co-firing based power generation system, carried out to investigate the impacts of biomass co-firing on system performance. The power generation system is a typical pulverized coal-fired steam cycle unit, in which four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel and two coals (bituminous coal and lignite are considered. Key system performance parameters are evaluated for various fuel combinations and co-firing ratios, using a system model and numerical simulation. The results indicate that plant energy efficiency decreases with increase of biomass proportion in the fuel mixture, and that the extent of the decrease depends on specific properties of the coal and biomass types.

  17. Motorcoach and school bus fire safety analysis : technology brief.

    Science.gov (United States)

    2016-11-01

    In 2009, the Federal Motor Carrier Safety Administration (FMCSA) published findings from a study entitled Motorcoach Fire Safety Analysis. The objective of this study was to gather and analyze information regarding the causes, frequency, and se...

  18. Detecting fire in video stream using statistical analysis

    Directory of Open Access Journals (Sweden)

    Koplík Karel

    2017-01-01

    Full Text Available The real time fire detection in video stream is one of the most interesting problems in computer vision. In fact, in most cases it would be nice to have fire detection algorithm implemented in usual industrial cameras and/or to have possibility to replace standard industrial cameras with one implementing the fire detection algorithm. In this paper, we present new algorithm for detecting fire in video. The algorithm is based on tracking suspicious regions in time with statistical analysis of their trajectory. False alarms are minimized by combining multiple detection criteria: pixel brightness, trajectories of suspicious regions for evaluating characteristic fire flickering and persistence of alarm state in sequence of frames. The resulting implementation is fast and therefore can run on wide range of affordable hardware.

  19. Internal fire protection analysis for the United Kingdom EPR design

    Energy Technology Data Exchange (ETDEWEB)

    Laid, Abdallah [Nuclear New Build Generation Company Ltd. (NNB GenCo), Barnwood (United Kingdom). EDF Energy Plc.; Cesbron, Mickael [Service Etudes et Project Thermiques et Nucleaires (SEPTEN), Lyon (France). EDF-SA

    2015-12-15

    In the deterministic design basis analysis of the United Kingdom (UK) EPR based nuclear power plants all postulated initiating events are grouped into two different types, internal faults and internal/external hazards. ''Internal Fires'' is one of the internal hazards analysed at the design stage of the UK EPR. In effect, the main safety objective for fire protection is to ensure that all the required safety functions are performed in the event of an internal fire. To achieve this safety objective, provisions for protection against fire risks are taken to: (i) limit the spread of a fire, protect the safety functions of the facility; (ii) limit the propagation of smoke and dispersion of toxic, radioactive, inflammable, corrosive or explosive materials, and (iii) ensure the achievement of a safe shutdown state, personnel evacuation and all other necessary emergency actions. This paper presents the UK EPR approach on how the above provisions are applied. Such provisions involve implementing means of fire prevention, surveillance, firefighting and limiting fire consequences, appropriate to the risks inherent to the facility. Overall, the design of the UK EPR fire protection systems is based on three types of measures: prevention, containment and control.

  20. Fire risk evaluation using multicriteria analysis--a case study.

    Science.gov (United States)

    Vadrevu, Krishna Prasad; Eaturu, Anuradha; Badarinath, K V S

    2010-07-01

    Forest fires are one of the major causes of ecological disturbance and environmental concerns in tropical deciduous forests of south India. In this study, we use fuzzy set theory integrated with decision-making algorithm in a Geographic Information Systems (GIS) framework to map forest fire risk. Fuzzy set theory implements classes or groupings of data with boundaries that are not sharply defined (i.e., fuzzy) and consists of a rule base, membership functions, and an inference procedure. We used satellite remote sensing datasets in conjunction with topographic, vegetation, climate, and socioeconomic datasets to infer the causative factors of fires. Spatial-level data on these biophysical and socioeconomic parameters have been aggregated at the district level and have been organized in a GIS framework. A participatory multicriteria decision-making approach involving Analytical Hierarchy Process has been designed to arrive at a decision matrix that identified the important causative factors of fires. These expert judgments were then integrated using spatial fuzzy decision-making algorithm to map the forest fire risk. Results from this study were quite useful in identifying potential "hotspots" of fire risk, where forest fire protection measures can be taken in advance. Further, this study also demonstrates the potential of multicriteria analysis integrated with GIS as an effective tool in assessing "where and when" forest fires will most likely occur.

  1. The Numerical Simulation Application for Fire-Tube Boiler Heating Surface Safety Evaluation

    Directory of Open Access Journals (Sweden)

    Khaustov Sergei A.

    2016-01-01

    Full Text Available The numerical simulation is applied for fire-tube boiler heating surface safety estimation. Thermal processes in an inflatable fire-tube furnace during its emergency operation were simulated using the finite volume method with Euler approximation and the implicit pressure based algorithm. Study results reproduce failures connected with increasing of impasse aerodynamic resistance. The method of these failures prediction is suggested. Simulation has shown that entering the amount of coolant into combustion volume results in burner fan incapability to overcome the impasse resistance of the furnace. The simulation results are visually confirmed during the inspection of emergency boilers.

  2. Numerical simulation of fire spread in terminal 2 of Belgrade airport

    Directory of Open Access Journals (Sweden)

    Stevanović Žarko

    2007-01-01

    Full Text Available This paper concern the results of software fire spread process prototype in terminal 2 of Belgrade airport using computational fluid dynamics. Numerical simulation of fire for the most critical fire scenario has been performed, primarily obtaining the space and time distribution of: velocity, pressure, temperature, and smoke concentration, assuming that HVAC systems have been switched off and all doors on the evacuation ways have been opened, just as the fire started. Also, two simulations have been compared of the smoke ventilation and not ventilation for the same scenario. Within the framework of the results presentation, isosurfaces of constant temperature (100 ºC and smoke concentration (4000 ppm are presented, based on the numerical simulation. Progression of these surfaces along the terminal 2 coincides to the experimental and experience evidence, forming the plume zone just above the fireplace, and spreading in the zone of underground ceiling and stairwell openings. .

  3. Rim Fire and its Radiative impact Simulated in CESM/CARMA

    Science.gov (United States)

    Yu, P.; Toon, O. B.; Bardeen, C.; Bucholtz, A.; Rosenlof, K. H.; Saide, P. E.; da Silva, A. M., Jr.; Ziemba, L. D.; Jimenez, J. L.; Schwarz, J. P.; Wagner, N. L.; Lack, D. A.; Mills, M. J.; Reid, J. S.

    2015-12-01

    The Rim Fire of 2013, the third largest area burned by fire recorded in California history, is simulated by CESM1/CARMA. Modeled aerosol mass, number, effective radius, and extinction coefficient are within variability of data obtained from multiple airborne measurements and satellite measurements. Simulations suggest Rim Fire smoke may block 4-6% of sunlight reaching the surface, with a cooling efficiency around 120-150 W m-2 per unit aerosol optical depth. This study shows that exceptional events like the 2013 Rim Fire can be simulated by a climate model with one-degree resolution, though that resolution is still not sufficient to resolve the smoke peak near the source region.

  4. Fire Hazard Analysis for the Cold Neutron Source System

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jung Won; Kim, Young Ki; Wu, Sang Ik; Park, Young Cheol; Kim, Bong Soo; Kang, Mee Jin; Oh, Sung Wook

    2006-04-15

    As the Cold Neutron Source System for its installation in HANARO has been designing, the fire hazard analysis upon the CNS system becomes required under No. 2003-20 of the MOST notice, Technical Standard about the Fire Hazard Analysis. As a moderator, the strongly flammable hydrogen is filled in the hydrogen system of CNS. Against the fire or explosion in the reactor hall, accordingly, the physical damage on the reactor safety system should be evaluated in order to reflect the safety protection precaution in the design of CNS system. For the purpose of fire hazard analysis, the accident scenarios were divided into three: hydrogen leak during the hydrogen charging in the system, hydrogen leak during the normal operation of CNS, explosion of hydrogen buffer tank by the external fire. The analysis results can be summarized as follows. First, there is no physical damage threatening the reactor safety system although all hydrogen gas came out of the system then ignited as a jet fire. Second, since the CNS equipment island (CEI) is located enough away from the reactor, no physical damage caused by the buffer tank explosion is on the reactor in terms of the overpressure except the flying debris so that the light two-hour fireproof panel is installed in an one side of hydrogen buffer tank. Third, there are a few combustibles on the second floor of CEI so that the fire cannot be propagated to other areas in the reactor hall; however, the light two-hour fireproof panel will be built on the second floor against the external or internal fire so as to play the role of a fire protection area.

  5. The simulation of surface fire spread based on Rothermel model in windthrow area of Changbai Mountain (Jilin, China)

    Science.gov (United States)

    Yin, Hang; Jin, Hui; Zhao, Ying; Fan, Yuguang; Qin, Liwu; Chen, Qinghong; Huang, Liya; Jia, Xiang; Liu, Lijie; Dai, Yuhong; Xiao, Ying

    2018-03-01

    The forest-fire not only brings great loss to natural resources, but also destructs the ecosystem and reduces the soil fertility, causing some natural disasters as soil erosion and debris flow. However, due to the lack of the prognosis for forest fire spreading trend in forest fire fighting, it is difficult to formulate rational and effective fire-fighting scheme. In the event of forest fire, achieving accurate judgment to the fire behavior would greatly improve the fire-fighting efficiency, and reduce heavy losses caused by fire. Researches on forest fire spread simulation can effectively reduce the loss of disasters. The present study focused on the simulation of "29 May 2012" wildfire in windthrow area of Changbai Mountain. Basic data were retrieved from the "29 May 2012" wildfire and field survey. A self-development forest fire behavior simulated program based on Rothermel Model was used in the simulation. Kappa coefficient and Sørensen index were employed to evaluate the simulation accuracy. The results showed that: The perimeter of simulated burned area was 4.66 km, the area was 56.47 hm2 and the overlapped burned area was 33.68 hm2, and the estimated rate of fire spread was 0.259 m/s. Between the simulated fire and actual fire, the Kappa coefficient was 0.7398 and the Sørensen co-efficient was 0.7419. This proved the application of Rothermel model to conduct fire behavior simulation in windthrow meadow was feasible. It can achieve the goal of forecasting for the spread behavior in windthrow area of Changbai Mountain. Thus, our self-development program based on the Rothermel model can provide a effective forecast of fire spread, which will facilitate the fire suppression work.

  6. Fire hazard analysis for Plutonium Finishing Plant complex

    Energy Technology Data Exchange (ETDEWEB)

    MCKINNIS, D.L.

    1999-02-23

    A fire hazards analysis (FHA) was performed for the Plutonium Finishing Plant (PFP) Complex at the Department of Energy (DOE) Hanford site. The scope of the FHA focuses on the nuclear facilities/structures in the Complex. The analysis was conducted in accordance with RLID 5480.7, [DOE Directive RLID 5480.7, 1/17/94] and DOE Order 5480.7A, ''Fire Protection'' [DOE Order 5480.7A, 2/17/93] and addresses each of the sixteen principle elements outlined in paragraph 9.a(3) of the Order. The elements are addressed in terms of the fire protection objectives stated in paragraph 4 of DOE 5480.7A. In addition, the FHA also complies with WHC-CM-4-41, Fire Protection Program Manual, Section 3.4 [1994] and WHC-SD-GN-FHA-30001, Rev. 0 [WHC, 1994]. Objectives of the FHA are to determine: (1) the fire hazards that expose the PFP facilities, or that are inherent in the building operations, (2) the adequacy of the fire safety features currently located in the PFP Complex, and (3) the degree of compliance of the facility with specific fire safety provisions in DOE orders, related engineering codes, and standards.

  7. Fire hazard analysis for Plutonium Finishing Plant complex

    International Nuclear Information System (INIS)

    MCKINNIS, D.L.

    1999-01-01

    A fire hazards analysis (FHA) was performed for the Plutonium Finishing Plant (PFP) Complex at the Department of Energy (DOE) Hanford site. The scope of the FHA focuses on the nuclear facilities/structures in the Complex. The analysis was conducted in accordance with RLID 5480.7, [DOE Directive RLID 5480.7, 1/17/94] and DOE Order 5480.7A, ''Fire Protection'' [DOE Order 5480.7A, 2/17/93] and addresses each of the sixteen principle elements outlined in paragraph 9.a(3) of the Order. The elements are addressed in terms of the fire protection objectives stated in paragraph 4 of DOE 5480.7A. In addition, the FHA also complies with WHC-CM-4-41, Fire Protection Program Manual, Section 3.4 [1994] and WHC-SD-GN-FHA-30001, Rev. 0 [WHC, 1994]. Objectives of the FHA are to determine: (1) the fire hazards that expose the PFP facilities, or that are inherent in the building operations, (2) the adequacy of the fire safety features currently located in the PFP Complex, and (3) the degree of compliance of the facility with specific fire safety provisions in DOE orders, related engineering codes, and standards

  8. Simulating fire regimes in the Amazon in response to climate change and deforestation.

    Science.gov (United States)

    Silvestrini, Rafaella Almeida; Soares-Filho, Britaldo Silveira; Nepstad, Daniel; Coe, Michael; Rodrigues, Hermann; Assunção, Renato

    2011-07-01

    Fires in tropical forests release globally significant amounts of carbon to the atmosphere and may increase in importance as a result of climate change. Despite the striking impacts of fire on tropical ecosystems, the paucity of robust spatial models of forest fire still hampers our ability to simulate tropical forest fire regimes today and in the future. Here we present a probabilistic model of human-induced fire occurrence for the Amazon that integrates the effects of a series of anthropogenic factors with climatic conditions described by vapor pressure deficit. The model was calibrated using NOAA-12 night satellite hot pixels for 2003 and validated for the years 2002, 2004, and 2005. Assessment of the fire risk map yielded fitness values > 85% for all months from 2002 to 2005. Simulated fires exhibited high overlap with NOAA-12 hot pixels regarding both spatial and temporal distributions, showing a spatial fit of 50% within a radius of 11 km and a maximum yearly frequency deviation of 15%. We applied this model to simulate fire regimes in the Amazon until 2050 using IPCC's A2 scenario climate data from the Hadley Centre model and a business-as-usual (BAU) scenario of deforestation and road expansion from SimAmazonia. Results show that the combination of these scenarios may double forest fire occurrence outside protected areas (PAs) in years of extreme drought, expanding the risk of fire even to the northwestern Amazon by midcentury. In particular, forest fires may increase substantially across southern and southwestern Amazon, especially along the highways slated for paving and in agricultural zones. Committed emissions from Amazon forest fires and deforestation under a scenario of global warming and uncurbed deforestation may amount to 21 +/- 4 Pg of carbon by 2050. BAU deforestation may increase fires occurrence outside PAs by 19% over the next four decades, while climate change alone may account for a 12% increase. In turn, the combination of climate change

  9. Modeling the Effect of Climate Change on Large Fire Size, Counts, and Intensities Using the Large Fire Simulator (FSim)

    Science.gov (United States)

    Riley, K. L.; Haas, J. R.; Finney, M.; Abatzoglou, J. T.

    2013-12-01

    Changes in climate can be expected to cause changes in wildfire activity due to a combination of shifts in weather (temperature, precipitation, relative humidity, wind speed and direction) and vegetation. Changes in vegetation could include type conversions, altered forest structure, and shifts in species composition, the effects of which could be mitigated or exacerbated by management activities. Further, changes in suppression response and effectiveness may alter potential wildfire activity, as well as the consequences of wildfire. Feedbacks among these factors are extremely complex and uncertain. The ability to anticipate changes driven by fire weather (largely outside of human control) can lead to development of fire and fuel management strategies aimed at mitigating current and future risk. Therefore, in this study we focus on isolating the effects of climate-induced changes in weather on wildfire activity. Specifically, we investigated the effect of changes in weather on fire activity in the Canadian Rockies ecoregion, which encompasses Glacier National Park and several large wilderness areas to the south. To model the ignition, growth, and containment of wildfires, we used the Large Fire Simulator (FSim), which we coupled with current and projected future climatic conditions. Weather streams were based on data from 14 downscaled Global Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) using the Representative Concentration Pathways (RCP) 45 and 85 for the years 2040-2060. While all GCMs indicate increases in temperature for this area, which would be expected to exacerbate fire activity, precipitation predictions for the summer wildfire season are more variable, ranging from a decrease of approximately 50 mm to an increase of approximately 50 mm. Windspeeds are generally predicted to decrease, which would reduce rates of spread and fire intensity. The net effect of these weather changes on the size, number, and intensity

  10. Simulating wildfire spread behavior between two NASA Active Fire data timeframes

    Science.gov (United States)

    Adhikari, B.; Hodza, P.; Xu, C.; Minckley, T. A.

    2017-12-01

    Although NASA's Active Fire dataset is considered valuable in mapping the spatial distribution and extent of wildfires across the world, the data is only available at approximately 12-hour time intervals, creating uncertainties and risks associated with fire spread and behavior between the two Visible Infrared Imaging Radiometer Satellite (VIIRS) data collection timeframes. Our study seeks to close the information gap for the United States by using the latest Active Fire data collected for instance around 0130 hours as an ignition source and critical inputs to a wildfire model by uniquely incorporating forecasted and real-time weather conditions for predicting fire perimeter at the next 12 hour reporting time (i.e. around 1330 hours). The model ingests highly dynamic variables such as fuel moisture, temperature, relative humidity, wind among others, and prompts a Monte Carlo simulation exercise that uses a varying range of possible values for evaluating all possible wildfire behaviors. The Monte Carlo simulation implemented in this model provides a measure of the relative wildfire risk levels at various locations based on the number of times those sites are intersected by simulated fire perimeters. Model calibration is achieved using data at next reporting time (i.e. after 12 hours) to enhance the predictive quality at further time steps. While initial results indicate that the calibrated model can predict the overall geometry and direction of wildland fire spread, the model seems to over-predict the sizes of most fire perimeters possibly due to unaccounted fire suppression activities. Nonetheless, the results of this study show great promise in aiding wildland fire tracking, fighting and risk management.

  11. Oblique electron fire hose instability: Particle-in-cell simulations

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Trávníček, Pavel M.; Decyk, V.; Schriver, D.

    2014-01-01

    Roč. 119, č. 1 (2014), s. 59-68 ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2041 Institutional support: RVO:67985815 Keywords : electron temperature anisotropy * fire hose instability Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.426, year: 2014

  12. Challenges and needs in fire management: A landscape simulation modeling perspective [chapter 4

    Science.gov (United States)

    Robert E. Keane; Geoffrey J. Cary; Mike D. Flannigan

    2011-01-01

    Fire management will face many challenges in the future from global climate change to protecting people, communities, and values at risk. Simulation modeling will be a vital tool for addressing these challenges but the next generation of simulation models must be spatially explicit to address critical landscape ecology relationships and they must use mechanistic...

  13. Design and Realization of Ship Fire Simulation Training System Based on Unity3D

    Science.gov (United States)

    Ting, Ye; Feng, Chen; Wenqiang, Wang; Kai, Yang

    2018-01-01

    Ship fire training is a very important training to ensure the safety of the ship, but limited by the characteristics of the ship itself, it is difficult to carry out fire training on the ship. This paper proposes to introduce a virtual reality technology to build a set of ship fire simulation training system, used to improve the quality of training, reduce training costs. First, the system design ideas are elaborated, and the system architecture diagram is given. Then, the key technologies in the process of system implementation are analyzed. Finally, the system examples are built and tested.

  14. Deforestation fire carbon emissions for the last millennium simulated with the global vegetation model JSBACH

    Science.gov (United States)

    Engels, Jessica; Kloster, Silvia; Wilkenskjeld, Stiig

    2013-04-01

    Humankind has fundamentally modified the Earth's terrestrial surface to secure food and other resources by conversion of natural ecosystems to managed areas. Until today, these anthropogenic changes in land cover have resulted in an extent of conversion from natural land cover by human activities to managed areas between one-third and one-half of the total Earth's land cover (Vitousek (1997)). Large parts of this conversion take place in the form of deforestation fires, which release atmospheric trace gases and aerosols into the atmosphere. These deforestation fires are climate dependent and follow a strong seasonal cycle, which is important for atmospheric chemistry. In the present study, the offline version of the JSBACH carbon pool model of the Max Planck Institute for Meteorology (MPI-M) is used to simulate climate dependent deforestation fire carbon emissions over the last millennium (800-2010). For this, the standard carbon allocation scheme is extended by four additional anthropogenic carbon pools. These pools separate the carbon amount released due to anthropogenic land cover change from the carbon amount released due to natural processes to the atmosphere. The climate dependent deforestation fire emissions are simulated in the model by a linear dependency on the soil moisture. This new carbon allocation scheme results in land cover change carbon emissions, which accumulate between 800 and 2010 to 239.8 PgC. Thereby, the climate dependent deforestation fire carbon emissions accumulate over the last millennium to 182.6 PgC yr-1 in the year 2010, which accounts for 76% of the total land cover change carbon emissions. Compared to present day satellite based observational data sets (GFED3) the simulated mean deforestation fire carbon emissions (1422.5 TgC yr-1) averaged over the time period 1997-2009 are about a factor of 4 higher than the observed carbon emissions (386.4 TgC yr-1) on a global scale. However, compared to a field-observational based estimate

  15. Need for a probabilistic fire analysis at nuclear power plants

    International Nuclear Information System (INIS)

    Calabuig Beneyto, J. L.; Ibanez Aparicio, J.

    1993-01-01

    Although fire protection standards for nuclear power plants cover a wide scope and are constantly being updated, the existence of certain constraints makes it difficult to precisely evaluate plant response to different postulatable fires. These constraints involve limitations such as: - Physical obstacles which impede the implementation of standards in certain cases; - Absence of general standards which cover all the situations which could arise in practice; - Possible temporary noncompliance of safety measures owing to unforeseen circumstances; - The fact that a fire protection standard cannot possibly take into account additional damages occurring simultaneously with the fire; Based on the experience of the ASCO NPP PSA developed within the framework of the joint venture, INITEC-INYPSA-EMPRESARIOS AGRUPADOS, this paper seeks to justify the need for a probabilistic analysis to overcome the limitations detected in general application of prevailing standards. (author)

  16. DAYCENT Simulations to Test the Influence of Fire Regime and Fire Suppression on Trace Gas Fluxes and Nitrogen Biogeochemistry of Colorado Forests

    Directory of Open Access Journals (Sweden)

    Mark A. Gathany

    2012-07-01

    Full Text Available Biological activity and the physical environment regulate greenhouse gas fluxes (CH4, N2O and NO from upland soils. Wildfires are known to alter these factors such that we collected daily weather records, fire return intervals, or specific fire years, and soil data of four specific sites along the Colorado Front Range. These data were used as primary inputs into DAYCENT. In this paper we test the ability of DAYCENT to simulate four forested sites in this area and to address two objectives: (1 to evaluate the short-term influence of fire on trace gas fluxes from burned landscapes; and (2 to compare trace gas fluxes among locations and between pre-/post- fire suppression. The model simulations indicate that CH4 oxidation is relatively unaffected by wildfire. In contrast, gross nitrification rates were reduced by 13.5–37.1% during the fire suppression period. At two of the sites, we calculated increases in gross nitrification rates (>100%, and N2O and NO fluxes during the year of fire relative to the year before a fire. Simulated fire suppression exhibited decreased gross nitrification rates presumably as nitrogen is immobilized. This finding concurs with other studies that highlight the importance of forest fires to maintain soil nitrogen availability.

  17. VISUAL-SEVEIF, a tool for integrating fire behavior simulation and economic evaluation of the impact of Wildfires

    Science.gov (United States)

    Francisco Rodríguez y Silva; Juan Ramón Molina Martínez; Miguel Ángel Herrera Machuca; Jesús Mª Rodríguez Leal

    2013-01-01

    Progress made in recent years in fire science, particularly as applied to forest fire protection, coupled with the increased power offered by mathematical processors integrated into computers, has led to important developments in the field of dynamic and static simulation of forest fires. Furthermore, and similarly, econometric models applied to economic...

  18. A Causal Inference Analysis of the Effect of Wildland Fire ...

    Science.gov (United States)

    Wildfire smoke is a major contributor to ambient air pollution levels. In this talk, we develop a spatio-temporal model to estimate the contribution of fire smoke to overall air pollution in different regions of the country. We combine numerical model output with observational data within a causal inference framework. Our methods account for aggregation and potential bias of the numerical model simulation, and address uncertainty in the causal estimates. We apply the proposed method to estimation of ozone and fine particulate matter from wildland fires and the impact on health burden assessment. We develop a causal inference framework to assess contributions of fire to ambient PM in the presence of spatial interference.

  19. Oblique electron fire hose instability: Particle-in-cell simulations

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Trávníček, Pavel M.; Decyk, V.; Schriver, D.

    2014-01-01

    Roč. 119, č. 1 (2014), s. 59-68 ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2041 Grant - others:European Commission(XE) 284515 Institutional support: RVO:68378289 Keywords : electron temperature anisotropy * fire hose instability Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.426, year: 2014 http://onlinelibrary.wiley.com/doi/10.1002/2013JA019227/abstract

  20. Analysis of simulator training

    International Nuclear Information System (INIS)

    Hollnagel, E.

    1983-01-01

    A method has been developed for systematic observation of operator performance in nuclear training simulators which combines training and research. It is based on generally accepted theories of operator models and decision making developed at Riso and elsewhere. It makes explicitly available the data which experienced instructors implicitly use in their assessment of operator performance. This means that the feed-back/debriefing function of the training is facilitated, it becomes possible to use normal training sessions to obtain data which can be used in further theoretical studies of e.g. operator decision making, and the generalized description of operator performance may be used to evaluate the training program as such. The method for observation is designed in cooperation with the instructors so that it does not interfere with their normal work. It is based on a detailed prior analysis of experienced transients, leading to a description of an expected performance, and some transient-in-dependent observation schemes, which are used to characterize points where the actual performance deviates from the expected performance. The analysis of the observations takes place according to the structure of a general model of analysis developed from numerous studies of operator performance, in real life and in simulators. (author)

  1. Immersive virtual reality-based training improves response in a simulated operating room fire scenario.

    Science.gov (United States)

    Sankaranarayanan, Ganesh; Wooley, Lizzy; Hogg, Deborah; Dorozhkin, Denis; Olasky, Jaisa; Chauhan, Sanket; Fleshman, James W; De, Suvranu; Scott, Daniel; Jones, Daniel B

    2018-01-25

    SAGES FUSE curriculum provides didactic knowledge on OR fire prevention. The objective of this study is to evaluate the impact of an immersive virtual reality (VR)-based OR fire training simulation system in combination with FUSE didactics. The study compared a control with a simulation group. After a pre-test questionnaire that assessed the baseline knowledge, both groups were given didactic material that consists of a 10-min presentation and reading materials about precautions and stopping an OR fire from the FUSE manual. The simulation group practiced on the OR fire simulation for one session that consisted of five trials within a week from the pre-test. One week later, both groups were reassessed using a questionnaire. A week after the post-test both groups also participated in a simulated OR fire scenario while their performance was videotaped for assessment. A total of 20 subjects (ten per group) participated in this IRB approved study. Median test scores for the control group increased from 5.5 to 9.00 (p = 0.011) and for the simulation group it increased from 5.0 to 8.5 (p = 0.005). Both groups started at the same baseline (pre-test, p = 0.529) and reached similar level in cognitive knowledge (post-test, p = 0.853). However, when tested in the mock OR fire scenario, 70% of the simulation group subjects were able to perform the correct sequence of steps in extinguishing the simulated fire whereas only 20% subjects in the control group were able to do so (p = 0.003). The simulation group was better than control group in correctly identifying the oxidizer (p = 0.03) and ignition source (p = 0.014). Interactive VR-based hands-on training was found to be a relatively inexpensive and effective mode for teaching OR fire prevention and management scenarios.

  2. Coupled simulation of a tangentially hard coal fired 700 °C boiler

    OpenAIRE

    Schuhbauer, C.; Angerer, M.; Spliethoff, H.; Kluger, F.; Tschaffon, H.

    2015-01-01

    This paper presents the coupled simulation of steam cycle and firing of the 700 ° C boiler. The focus is on the implementation of the coupling algorithm and the modification of the implemented ANSYS FLUENT models to adjust the simulation to the specific boundary conditions of a pulverized coal combustion in a tower-type boiler. Therefore the necessary simulation fundamentals are explained. This includes the used software packages and the combustion modeling in ANSYS FLUENT a...

  3. Simulator training analysis

    International Nuclear Information System (INIS)

    Hollnagel, E.; Rasmussen, J.

    1981-08-01

    This paper presents a suggestion for systematic collection of data during the normal use of training simulators, with the double purpose of supporting trainee debriefing and providing data for further theoretical studies of operator performance. The method is based on previously described models of operator performance and decision-making, and is a specific instance of the general method for analysis of operator performance data. The method combines a detailed transient-specific description of the expected performance with transient-independent tools for observation of critical activities. (author)

  4. Effectiveness of Fire and Fire Surrogate Treatments For Controlling Wildfire Behavior in Piedmont Forests: A Simulation Study

    Science.gov (United States)

    Helen H. Mohr; Thomas A. Waldrop; Sandra Rideout; Ross J. Phillips; Charles T. Flint

    2004-01-01

    The need for fuel reduction has increased in United States forests due to decades of fire exclusion. Excessive fuel buildup has led to uncharacteristically severe fires in areas with historically short-interval, low-to-moderate-intensity fire regimes. The National Fire and Fire Surrogate (NFFS) Study compared the impacts of three fuel-reduction treatments on numerous...

  5. Forest fires in Pennsylvania.

    Science.gov (United States)

    Donald A. Haines; William A. Main; Eugene F. McNamara

    1978-01-01

    Describes factors that contribute to forest fires in Pennsylvania. Includes an analysis of basic statistics; distribution of fires during normal, drought, and wet years; fire cause, fire activity by day-of-week; multiple-fire day; and fire climatology.

  6. A Cellular Automata-Based Simulation Tool for Real Fire Accident Prevention

    Directory of Open Access Journals (Sweden)

    Jacek M. Czerniak

    2018-01-01

    Full Text Available Many serious real-life problems could be simulated using cellular automata theory. There were a lot of fires in public places which kill many people. Proposed method, called Cellular Automata Evaluation (CAEva in short, is using cellular automata theory and could be used for checking buildings conditions for fire accident. The tests performed on real accident showed that an appropriately configured program allows obtaining a realistic simulation of human evacuation. The authors analyze some real accidents and proved that CAEva method appears as a very promising solution, especially in the cases of building renovations or temporary unavailability of escape routes.

  7. Large eddy simulation of a mechanically ventilated compartment fire for nuclear applications

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Bao P. [Dalian Univ. of Technology (China). Faculty of Energy and Power Engineering; Wen, Jennifer X. [Warwick Univ. (United Kingdom). Warwick FIRE, School of Engineering

    2015-12-15

    This paper deals with the modelling of a mechanically ventilated compartment fire which is a commonplace in nuclear fire scenarios. An advanced Computational Fluid Dynamics (CFD) field model with a wall conjugate heat transfer treatment is proposed. It simultaneously solves the compartment fire flow and the wall heat conduction. The flow solver is based on the Large Eddy Simulation (LES) based fire simulation solver FireFOAM within the frame of open source CFD code OpenFOAM {sup registered}. An extended eddy dissipation model is used to calculate the chemical reaction rate. A soot model based on the concept of smoke point height is employed to model the soot formation and oxidation. A finite volume method is adopted to model the radiative heat transfer. The ventilation flow is modelled by a simplified Bernoulli equation neglecting the detailed information on the ventilation system. The proposed model is validated against a single room fire test with forced mechanical ventilations. The predictions are in reasonably good agreement with experimental data.

  8. A Drone Remote Sensing for Virtual Reality Simulation System for Forest Fires: Semantic Neural Network Approach

    Science.gov (United States)

    Narasimha Rao, Gudikandhula; Jagadeeswara Rao, Peddada; Duvvuru, Rajesh

    2016-09-01

    Wild fires have significant impact on atmosphere and lives. The demand of predicting exact fire area in forest may help fire management team by using drone as a robot. These are flexible, inexpensive and elevated-motion remote sensing systems that use drones as platforms are important for substantial data gaps and supplementing the capabilities of manned aircraft and satellite remote sensing systems. In addition, powerful computational tools are essential for predicting certain burned area in the duration of a forest fire. The reason of this study is to built up a smart system based on semantic neural networking for the forecast of burned areas. The usage of virtual reality simulator is used to support the instruction process of fire fighters and all users for saving of surrounded wild lives by using a naive method Semantic Neural Network System (SNNS). Semantics are valuable initially to have a enhanced representation of the burned area prediction and better alteration of simulation situation to the users. In meticulous, consequences obtained with geometric semantic neural networking is extensively superior to other methods. This learning suggests that deeper investigation of neural networking in the field of forest fires prediction could be productive.

  9. Global fire activity patterns (1996─2006 and climatic influence: an analysis using the World Fire Atlas

    Directory of Open Access Journals (Sweden)

    D. Oom

    2008-04-01

    Full Text Available Vegetation fires have been acknowledged as an environmental process of global scale, which affects the chemical composition of the troposphere, and has profound ecological and climatic impacts. However, considerable uncertainty remains, especially concerning intra and inter-annual variability of fire incidence. The main goals of our global-scale study were to characterise spatial-temporal patterns of fire activity, to identify broad geographical areas with similar vegetation fire dynamics, and to analyse the relationship between fire activity and the El Niño-Southern Oscillation. This study relies on 10 years (mid 1996–mid 2006 of screened European Space Agency World Fire Atlas (WFA data, obtained from Along Track Scanning Radiometer (ATSR and Advanced ATSR (AATSR imagery. Empirical Orthogonal Function analysis was used to reduce the dimensionality of the dataset. Regions of homogeneous fire dynamics were identified with cluster analysis, and interpreted based on their eco-climatic characteristics. The impact of 1997–1998 El Niño is clearly dominant over the study period, causing increased fire activity in a variety of regions and ecosystems, with variable timing. Overall, this study provides the first global decadal assessment of spatial-temporal fire variability and confirms the usefulness of the screened WFA for global fire ecoclimatology research.

  10. Numerical simulations of LNG vapor dispersion in Brayton Fire Training Field tests with ANSYS CFX.

    Science.gov (United States)

    Qi, Ruifeng; Ng, Dedy; Cormier, Benjamin R; Mannan, M Sam

    2010-11-15

    Federal safety regulations require the use of validated consequence models to determine the vapor cloud dispersion exclusion zones for accidental liquefied natural gas (LNG) releases. One tool that is being developed in industry for exclusion zone determination and LNG vapor dispersion modeling is computational fluid dynamics (CFD). This paper uses the ANSYS CFX CFD code to model LNG vapor dispersion in the atmosphere. Discussed are important parameters that are essential inputs to the ANSYS CFX simulations, including the atmospheric conditions, LNG evaporation rate and pool area, turbulence in the source term, ground surface temperature and roughness height, and effects of obstacles. A sensitivity analysis was conducted to illustrate uncertainties in the simulation results arising from the mesh size and source term turbulence intensity. In addition, a set of medium-scale LNG spill tests were performed at the Brayton Fire Training Field to collect data for validating the ANSYS CFX prediction results. A comparison of test data with simulation results demonstrated that CFX was able to describe the dense gas behavior of LNG vapor cloud, and its prediction results of downwind gas concentrations close to ground level were in approximate agreement with the test data. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Fire and Smoke Model Evaluation Experiment (FASMEE): Modeling gaps and data needs

    Science.gov (United States)

    Yongqiang Liu; Adam Kochanski; Kirk Baker; Ruddy Mell; Rodman Linn; Ronan Paugam; Jan Mandel; Aime Fournier; Mary Ann Jenkins; Scott Goodrick; Gary Achtemeier; Andrew Hudak; Matthew Dickson; Brian Potter; Craig Clements; Shawn Urbanski; Roger Ottmar; Narasimhan Larkin; Timothy Brown; Nancy French; Susan Prichard; Adam Watts; Derek McNamara

    2017-01-01

    Fire and smoke models are numerical tools for simulating fire behavior, smoke dynamics, and air quality impacts of wildland fires. Fire models are developed based on the fundamental chemistry and physics of combustion and fire spread or statistical analysis of experimental data (Sullivan 2009). They provide information on fire spread and fuel consumption for safe and...

  12. Determination of Ignitable Liquids in Fire Debris: Direct Analysis by Electronic Nose

    Directory of Open Access Journals (Sweden)

    Marta Ferreiro-González

    2016-05-01

    Full Text Available Arsonists usually use an accelerant in order to start or accelerate a fire. The most widely used analytical method to determine the presence of such accelerants consists of a pre-concentration step of the ignitable liquid residues followed by chromatographic analysis. A rapid analytical method based on headspace-mass spectrometry electronic nose (E-Nose has been developed for the analysis of Ignitable Liquid Residues (ILRs. The working conditions for the E-Nose analytical procedure were optimized by studying different fire debris samples. The optimized experimental variables were related to headspace generation, specifically, incubation temperature and incubation time. The optimal conditions were 115 °C and 10 min for these two parameters. Chemometric tools such as hierarchical cluster analysis (HCA and linear discriminant analysis (LDA were applied to the MS data (45–200 m/z to establish the most suitable spectroscopic signals for the discrimination of several ignitable liquids. The optimized method was applied to a set of fire debris samples. In order to simulate post-burn samples several ignitable liquids (gasoline, diesel, citronella, kerosene, paraffin were used to ignite different substrates (wood, cotton, cork, paper and paperboard. A full discrimination was obtained on using discriminant analysis. This method reported here can be considered as a green technique for fire debris analyses.

  13. Analysis Evacuation Route for KM Zahro Express on Fire Condition using Agent Based Modeling and Fire Dynamics Simulatior

    Directory of Open Access Journals (Sweden)

    Trika Pitana

    2017-09-01

    Full Text Available Safety is the thing that needs to be preferred by users of transport, passengers should also understand about safety procedures and evacuation procedures in the means of transport. There have been many accidents that happen in the world of transport, particularly in the shipping world, from 2010 to 2016 is no more than 50 accidents of ships in accordance with the cause recorded by KNKT (Komisi Nasional Keselamatan Transportasi. On this research was discussed the evacuation time on the ship KM Zahro express that occurred earlier in the year 2017 in the Kepulauan Seribu, DKI Jakarta. Almost all passenger dead caused by fire from power source in engine room. This thesis will explaine about evacuation time and dangers from fire that interfere the process of evacuation. The methods used are Agent Based Modeling and Simulation (ABMS and Fire Dynamics Simulator (FDS for modeling fire simulation. Agent-Based Modeling software (pathfinder and Fire Dynamics Simulator software (pyrosim are used to calculate time evacuation in normal condition and fire condition of KM Zahro Express. Agent-Based Modeling and Simulator (ABMS is a modeling method that aims to model complex problems based on real cases. Agent-Based Modeling and Simulator (ABMS is designed to model a place that has a seat, path, exit door, humans, and others. Pyrosim is a graphical user interface for the Fire Dynamics Simulator (FDS. FDS models can predict smoke, temperature, carbon monoxide, and other substances during fires.  In this case the existing models can be used to plan and prepare an emergency if unwanted things happen. As well as using basic rules which refer to the Safety Of Life At Sea (SOLAS and International Maritime Organization (IMO. Result of Evacuation simulation calculation on emergency conditions (two rear exit doors will be closed that match at actually condition is 29,783 minutes (respon is not taken in this simulation, calculation results obtained from simulation of

  14. Forest-fire models

    Science.gov (United States)

    Haiganoush Preisler; Alan Ager

    2013-01-01

    For applied mathematicians forest fire models refer mainly to a non-linear dynamic system often used to simulate spread of fire. For forest managers forest fire models may pertain to any of the three phases of fire management: prefire planning (fire risk models), fire suppression (fire behavior models), and postfire evaluation (fire effects and economic models). In...

  15. Numerical simulations of forest fire propagation and smoke transport as an external hazard assessment methodology development for a nuclear power plant

    International Nuclear Information System (INIS)

    Okano, Yasushi; Yamano, Hidemasa

    2016-01-01

    A new method has been developed to assess potential challenges by forest fire smoke on a cooling function of a decay heat removal system (DHRS) of a sodium-cooled fast reactor. Combinational numerical simulations of a forest fire propagation and a smoke transport were performed to evaluate a cumulative amount of smoke captured on air filters of the DHRS. The forest fire propagation simulations were performed using FARSITE code to evaluate a temporal increase of a forest fire spread area, a frontal fireline location, reaction intensity, and fireline intensity. Peripheral boundary of the forest fire spread area is shaped like an ellipse on the terrain, and the active forest fire area from which smoke is produced as a forest fire product is increased with forest fire spread. The smoke transport simulations were performed using ALOFT-FT code where a spatial distribution of smoke density, especially of particle matter (PM), is evaluated. The snapshot (i.e. at a certain time step) outputs by FARSITE on the reaction intensity and the fireline intensity were utilized as the input data for ALOFT-FT, while it was conservatively assumed that the smoke generated from the active forest fire area along the periphery boundary rises up from the frontal fireline location nearest to a nuclear power plant (NPP) and that prevailing wind transports all smoke to an NPP in the leeward side. The evaluated time-dependent changes of spatial PM density were utilized to calculate a cumulative amount of PM captured on the air filters of the DHRS. Sensitivity analysis was performed on prevailing wind speed to which both the fireline intensity and the smoke transport behavior are sensitive. The total amount of PM on the air filters was conservatively estimated around several hundred grams per m 2 which is well below the utilization limit. (author)

  16. Suppression of pool fires with HRC-125 in a simulated engine nacelle.

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, David R. (INS, Inc., Lexington Park, MD); Hewson, John C.

    2007-06-01

    CFD simulations are conducted to predict the distribution of fire suppressant in an engine nacelle and to predict the suppression of pool fires by the application of this suppressant. In the baseline configuration, which is based on an installed system, suppressant is injected through four nozzles at a rate fast enough to suppress all simulated pool fires. Variations that reduce the mass of the suppression system (reducing the impact of the suppression system on meeting mission needs) are considered, including a reduction in the rate of suppressant injection, a reduction in the mass of suppressant and a reduction in the number of nozzles. In general, these variations should work to reduce the effectiveness of the suppression system, but the CFD results point out certain changes that have negligible impact, at least for the range of phenomena considered here. The results are compared with measurements where available. Comparisons with suppressant measurements are reasonable. A series of twenty-three fire suppression tests were conducted to check the predictions. The pre-test predictions were generally successful in identifying the range of successful suppression tests. In two separate cases, each where one nozzle of the suppression system was capped, the simulation results did indicate a failure to suppress for a condition where the tests indicated successful suppression. When the test-suppressant discharge rate was reduced by roughly 25%, the tests were in agreement with the predictions. That is, the simulations predict a failure to suppress slightly before observed in these cases.

  17. Simulating forest fuel and fire risk dynamics across landscapes--LANDIS fuel module design

    Science.gov (United States)

    Hong S. He; Bo Z. Shang; Thomas R. Crow; Eric J. Gustafson; Stephen R. Shifley

    2004-01-01

    Understanding fuel dynamics over large spatial (103-106 ha) and temporal scales (101-103 years) is important in comprehensive wildfire management. We present a modeling approach to simulate fuel and fire risk dynamics as well as impacts of alternative fuel treatments. The...

  18. An algorithm to help design fire simulation and other data base work

    Science.gov (United States)

    Romain Mees

    1974-01-01

    The data necessary for fire simulation may be made available through an algorithm based on tracing of boundaries composed of straight-line segments. Useful assumptions are that if a closed boundary does not contain a given point, then any other closed boundary contained within the former one does not contain the location; and that a given location will be contained in...

  19. FDS5 Simulation for OECD PRISME Fire Test of DOOR PRSD5

    International Nuclear Information System (INIS)

    Lee, Kyu Bok; Park, Jong Seuk

    2009-01-01

    OECD/NEA PRISME Fire Project is an international co-operation project to investigate fire propagation by means of experiments and analyses for nuclear power plant applications. This project focuses on the generation of experimental data for fire and smoke propagation from the fire room to adjacent rooms under various conditions and room configurations. In addition, analyses using computer codes are performed to understand the phenomena of interest and to produce a consistent interpretation of the experimental results. The PRISME Project is composed of series of tests named as SOURCE, DOOR, LEAK and Global Tests. The SOURCE is composed of tests to characterize the fire source, and the DOOR is to study fire and smoke propagation through an open door, while the LEAK is to investigate hot gas leakages through other modes of openings such as holes, a slot, a duct, and a partially opened door. The Global test will be conducted as integral tests on the basis of the results of the previous separate effects tests. In this paper, simulations are performed with FDS5 computer code for the DOOR Test No.5 (PRS D 5) and the calculation results are compared with the corresponding experimental data to study the code capability to predict the phenomena of the hot gas propagation between two rooms

  20. Users Guide for Fire Image Analysis System - Version 5.0: A Tool for Measuring Fire Behavior Characteristics

    Science.gov (United States)

    Carl W. Adkins

    1995-01-01

    The Fire Image Analysis System is a tool for quantifying flame geometry and relative position at selected points along a spreading line fire. At present, the system requires uniform terrain (constant slope). The system has been used in field and laboratory studies for determining flame length, depth, cross sectional area, and rate of spread.

  1. Oblique proton fire hose instability in the expanding solar wind: Hybrid simulations

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Trávníček, Pavel M.

    2008-01-01

    Roč. 113, A10 (2008), A10109/1-A10109/9 ISSN 0148-0227 R&D Projects: GA AV ČR IAA300420702; GA AV ČR IAA300420602 Institutional research plan: CEZ:AV0Z30420517; CEZ:AV0Z10030501 Keywords : kinetic instability * fire hose * solar wind * fire hose instabilities * linear analysis * nonlinear evolution * solar wind Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.147, year: 2008

  2. FireStem2D — A two-dimensional heat transfer model for simulating tree stem injury in fires

    Science.gov (United States)

    Efthalia K. Chatziefstratiou; Gil Bohrer; Anthony S. Bova; Ravishankar Subramanian; Renato P.M. Frasson; Amy Scherzer; Bret W. Butler; Matthew B. Dickinson

    2013-01-01

    FireStem2D, a software tool for predicting tree stem heating and injury in forest fires, is a physically-based, two-dimensional model of stem thermodynamics that results from heating at the bark surface. It builds on an earlier one-dimensional model (FireStem) and provides improved capabilities for predicting fire-induced mortality and injury before a fire occurs by...

  3. Identification of fire modeling issues based on an analysis of real events from the OECD FIRE database

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, Dominik [Swiss Federal Nuclear Safety Inspectorate ENSI, Brugg (Switzerland)

    2017-03-15

    Precursor analysis is widely used in the nuclear industry to judge the significance of events relevant to safety. However, in case of events that may damage equipment through effects that are not ordinary functional dependencies, the analysis may not always fully appreciate the potential for further evolution of the event. For fires, which are one class of such events, this paper discusses modelling challenges that need to be overcome when performing a probabilistic precursor analysis. The events used to analyze are selected from the Organisation for Economic Cooperation and Development (OECD) Fire Incidents Records Exchange (FIRE) Database.

  4. High temperature corrosion under conditions simulating biomass firing: depth-resolved phase identification

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2014-01-01

    Both cross-sectional and plan view, ‘top-down’ characterization methods were employed , for a depth-resolved characterization of corrosion products resulting from high temperature corrosion under laboratory conditions simulating biomass firing. Samples of an austenitic stainless steel (TP 347H FG......) were coated with KCl and is o-thermally exposed at 560 o C for 168 h under a flue gas corresponding to straw firing. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD) characterization techniques were employed for comprehensive characterization...... of the corrosion product. Results from this comprehensive characterization revealed more details on the morphology and composition of the corrosion product....

  5. Fully predictive simulation of real-scale cable tray fire based on small-scale laboratory experiments

    Energy Technology Data Exchange (ETDEWEB)

    Beji, Tarek; Merci, Bart [Ghent Univ. (Belgium). Dept. of Flow, Heat and Combustion Mechanics; Bonte, Frederick [Bel V, Brussels (Belgium)

    2015-12-15

    This paper presents a computational fluid dynamics (CFD)-based modelling strategy for real-scale cable tray fires. The challenge was to perform fully predictive simulations (that could be called 'blind' simulations) using solely information from laboratory-scale experiments, in addition to the geometrical arrangement of the cables. The results of the latter experiments were used (1) to construct the fuel molecule and the chemical reaction for combustion, and (2) to estimate the overall pyrolysis and burning behaviour. More particularly, the strategy regarding the second point consists of adopting a surface-based pyrolysis model. Since the burning behaviour of each cable could not be tracked individually (due to computational constraints), 'groups' of cables were modelled with an overall cable surface area equal to the actual value. The results obtained for one large-scale test (a stack of five horizontal trays) are quite encouraging, especially for the peak Heat Release Rate (HRR) that was predicted with a relative deviation of 3 %. The time to reach the peak is however overestimated by 4.7 min (i.e. 94 %). Also, the fire duration is overestimated by 5 min (i.e. 24 %). These discrepancies are mainly attributed to differences in the HRRPUA (heat release rate per unit area) profiles between the small-scale and large-scale. The latter was calculated by estimating the burning area of cables using video fire analysis (VFA).

  6. Visibility analysis of fire lookout towers in the Boyabat State Forest Enterprise in Turkey.

    Science.gov (United States)

    Kucuk, Omer; Topaloglu, Ozer; Altunel, Arif Oguz; Cetin, Mehmet

    2017-07-01

    For a successful fire suppression, it is essential to detect and intervene forest fires as early as possible. Fire lookout towers are crucial assets in detecting forest fires, in addition to other technological advancements. In this study, we performed a visibility analysis on a network of fire lookout towers currently operating in a relatively fire-prone region in Turkey's Western Black Sea region. Some of these towers had not been functioning properly; it was proposed that these be taken out of the grid and replaced with new ones. The percentage of visible areas under the current network of fire lookout towers was 73%; it could rise to 81% with the addition of newly proposed towers. This study was the first research to conduct a visibility analysis of current and newly proposed fire lookout towers in the Western Black Sea region and focus on its forest fire problem.

  7. Risk Analysis for Road Tunnels – A Metamodel to Efficiently Integrate Complex Fire Scenarios

    DEFF Research Database (Denmark)

    Berchtold, Florian; Knaust, Christian; Arnold, Lukas

    2018-01-01

    Fires in road tunnels constitute complex scenarios with interactions between the fire, tunnel users and safety measures. More and more methodologies for risk analysis quantify the consequences of these scenarios with complex models. Examples for complex models are the computational fluid dynamics...... in risk analysis. We further emphasise that the metamodel is broadly applicable on various experimental or modelling issues in fire safety engineering....

  8. An ensemble approach to simulate CO2 emissions from natural fires

    Science.gov (United States)

    Eliseev, A. V.; Mokhov, I. I.; Chernokulsky, A. V.

    2014-06-01

    This paper presents ensemble simulations with the global climate model developed at the A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM). These simulations are forced by historical reconstructions of concentrations of well-mixed greenhouse gases (CO2, CH4, and N2O), sulfate aerosols (both in the troposphere and stratosphere), extent of crops and pastures, and total solar irradiance for AD 850-2005 (hereafter all years are taken as being AD) and by the Representative Concentration Pathway (RCP) scenarios for the same forcing agents until the year 2300. Our model implements GlobFIRM (Global FIRe Model) as a scheme for calculating characteristics of natural fires. Comparing to the original GlobFIRM model, in our implementation, the scheme is extended by a module accounting for CO2 release from soil during fires. The novel approach of our paper is to simulate natural fires in an ensemble fashion. Different ensemble members in the present paper are constructed by varying the values of parameters of the natural fires module. These members are constrained by the GFED-3.1 data set for the burnt area and CO2 release from fires and further subjected to Bayesian averaging. Our simulations are the first coupled model assessment of future changes in gross characteristics of natural fires. In our model, the present-day (1998-2011) global area burnt due to natural fires is (2.1 ± 0.4) × 106 km2 yr-1 (ensemble mean and intra-ensemble standard deviation are presented), and the respective CO2 emissions to the atmosphere are (1.4 ± 0.2) Pg C yr-1. The latter value is in agreement with the corresponding GFED estimates. The area burnt by natural fires is generally larger than the GFED estimates except in boreal Eurasia, where it is realistic, and in Australia, where it is smaller than these estimates. Regionally, the modelled CO2 emissions are larger (smaller) than the GFED estimates in Europe (in the tropics and north-eastern Eurasia). From

  9. Validation/Uncertainty Quantification for Large Eddy Simulations of the heat flux in the Tangentially Fired Oxy-Coal Alstom Boiler Simulation Facility

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.J.; Eddings, E.G.; Ring, T.; Thornock, J.; Draper, T.; Isaac, B.; Rezeai, D.; Toth, P.; Wu, Y.; Kelly, K.

    2014-08-01

    The objective of this task is to produce predictive capability with quantified uncertainty bounds for the heat flux in commercial-scale, tangentially fired, oxy-coal boilers. Validation data came from the Alstom Boiler Simulation Facility (BSF) for tangentially fired, oxy-coal operation. This task brings together experimental data collected under Alstom’s DOE project for measuring oxy-firing performance parameters in the BSF with this University of Utah project for large eddy simulation (LES) and validation/uncertainty quantification (V/UQ). The Utah work includes V/UQ with measurements in the single-burner facility where advanced strategies for O2 injection can be more easily controlled and data more easily obtained. Highlights of the work include: • Simulations of Alstom’s 15 megawatt (MW) BSF, exploring the uncertainty in thermal boundary conditions. A V/UQ analysis showed consistency between experimental results and simulation results, identifying uncertainty bounds on the quantities of interest for this system (Subtask 9.1) • A simulation study of the University of Utah’s oxy-fuel combustor (OFC) focused on heat flux (Subtask 9.2). A V/UQ analysis was used to show consistency between experimental and simulation results. • Measurement of heat flux and temperature with new optical diagnostic techniques and comparison with conventional measurements (Subtask 9.3). Various optical diagnostics systems were created to provide experimental data to the simulation team. The final configuration utilized a mid-wave infrared (MWIR) camera to measure heat flux and temperature, which was synchronized with a high-speed, visible camera to utilize two-color pyrometry to measure temperature and soot concentration. • Collection of heat flux and temperature measurements in the University of Utah’s OFC for use is subtasks 9.2 and 9.3 (Subtask 9.4). Several replicates were carried to better assess the experimental error. Experiments were specifically designed for the

  10. Incorporating field wind data into FIRETEC simulations of the International Crown Fire Modeling Experiment (ICFME): preliminary lessons learned

    Science.gov (United States)

    Rodman Linn; Kerry Anderson; Judith Winterkamp; Alyssa Broos; Michael Wotton; Jean-Luc Dupuy; Francois Pimont; Carleton Edminster

    2012-01-01

    Field experiments are one way to develop or validate wildland fire-behavior models. It is important to consider the implications of assumptions relating to the locality of measurements with respect to the fire, the temporal frequency of the measured data, and the changes to local winds that might be caused by the experimental configuration. Twenty FIRETEC simulations...

  11. Fuel loads and simulated fire behavior in "old-stage" beetle-infested ponderosa pine of the Colorado Plateau

    Science.gov (United States)

    E. Matthew Hansen; Morris C. Johnson; Barbara J. Bentz; James C. Vandygriff; A. Steven. Munson

    2015-01-01

    Recent bark beetle outbreaks in western North America have led to concerns regarding changes in fuel profiles and associated changes in fire behavior. Data are lacking for a range of infestation severities and time since outbreak, especially for relatively arid cover types. We surveyed fuel loads and simulated fire behavior for ponderosa pine stands of the...

  12. Econometric analysis of fire suppression production functions for large wildland fires

    Science.gov (United States)

    Thomas P. Holmes; David E. Calkin

    2013-01-01

    In this paper, we use operational data collected for large wildland fires to estimate the parameters of economic production functions that relate the rate of fireline construction with the level of fire suppression inputs (handcrews, dozers, engines and helicopters). These parameter estimates are then used to evaluate whether the productivity of fire suppression inputs...

  13. When can refuges mediate the genetic effects of fire regimes? A simulation study of the effects of topography and weather on neutral and adaptive genetic diversity in fire-prone landscapes.

    Science.gov (United States)

    Banks, Sam C; Davies, Ian D; Cary, Geoffrey J

    2017-10-01

    Understanding how landscape heterogeneity mediates the effects of fire on biodiversity is increasingly important under global changes in fire regimes. We used a simulation experiment to investigate how fire regimes interact with topography and weather to shape neutral and selection-driven genetic diversity under alternative dispersal scenarios, and to explore the conditions under which microrefuges can maintain genetic diversity of populations exposed to recurrent fire. Spatial heterogeneity in simulated fire frequency occurred in topographically complex landscapes, with fire refuges and fire-prone "hotspots" apparent. Interannual weather variability reduced the effect of topography on fire patterns, with refuges less apparent under high weather variability. Neutral genetic diversity was correlated with long-term fire frequency under spatially heterogeneous fire regimes, being higher in fire refuges than fire-prone areas, except under high dispersal or low fire severity (low mortality). This generated different spatial genetic structures in fire-prone and fire-refuge components of the landscape, despite similar dispersal. In contrast, genetic diversity was only associated with time since the most recent fire in flat landscapes without predictable refuges and hotspots. Genetic effects of selection driven by fire-related conditions depended on selection pressure, migration distance and spatial heterogeneity in fire regimes. Allele frequencies at a locus conferring higher fitness under successional environmental conditions followed a pattern of "temporal adaptation" to contemporary conditions under strong selection pressure and high migration. However, selected allele frequencies were correlated with spatial variation in long-term mean fire frequency (relating to environmental predictability) under weak dispersal, low selection pressure and strong spatial heterogeneity in fire regimes. © 2017 John Wiley & Sons Ltd.

  14. Simulation of fire in a deposit of radioactive waste and the radiological risk associated to this scenario

    Energy Technology Data Exchange (ETDEWEB)

    Domingos, Érica Nascimento; Lima, Zelmo Rodrigues de, E-mail: erica.ndomingos@gmail.com, E-mail: zrlima@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Aguiar, Laís Alencar de, E-mail: laguiars@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    A fire at radioactive waste deposit can result in significant damage as well as serious risks to the environment and the health of the general public. The CNEN (National Commission of Nuclear Energy) norms have fire protection regulations criteria and requirements to prevent the occurrence, neutralize the action and minimize the effects of the fire on the radioactive material present on the plant. These norms it is for to avoid or limit to the lowest possible levels the effects of ionizing radiation or toxic substances on humans and the environment. Before a possible fire containing radioactive material is necessary information that can estimate the dose in which the population will be submitted. In this work the proposal is to simulate a fire scenario containing radioactive material using Hotspot Health Physics simulation code and to identify the radiological risk of cancer in the respiratory system associated with this scenario using the BEIR V model. (author)

  15. Analysis of thermal radiation in coal-fired furnaces

    Science.gov (United States)

    Miles, Jonathan J.; Hammaker, Robert G.; Madding, Robert P.; Sunderland, J. E.

    1997-04-01

    Many utilities throughout the United States have added infrared scanning to their arsenal of techniques for inspection and predictive maintenance programs. Commercial infrared scanners are not designed, however, to withstand the searing interiors of boilers, which can exceed 2500 degrees Fahrenheit. Two high-temperature lenses designed to withstand the hostile environment inside a boiler for extended periods of time were developed by the EPRI M&D Center, thus permitting real-time measurement of steam tube temperatures and subsequent analysis of tube condition, inspection of burners, and identification of hot spots. A study was conducted by Sunderland Engineering, Inc. and EPRI M&D in order to characterize the radiative interactions that affect infrared measurements made inside a commercial, coal- fired, water-tube boiler. A comprehensive literature search exploring the existing record of results pertaining to analytical and experimental determination of radiative properties of coal-combustion byproducts was performed. An experimental component intended to provide data for characterization of the optical properties of hot combustion byproducts inside a coal-fired furnace was carried out. The results of the study indicate that hot gases, carbon particles, and fly ash, which together compose the medium inside a boiler, affect to varying degrees the transport of infrared radiation across a furnace. Techniques for improved infrared measurement across a coal-fired furnace are under development.

  16. Laboratory Investigations of the High Temperature Corrosion of Various Materials in Simulated oxy-fuel and Conventional Coal Firing

    International Nuclear Information System (INIS)

    Folkeson, N.; Pettersson, J.; Svensson, J.E.; Hjornhede, A.; Montgomery, M.; Bjurman, M.

    2009-01-01

    Laboratory exposures in horizontal tube furnaces were conducted to test various materials for corrosion resistance in simulated oxy-fuel firing and conventional coal firing environments. Two different exposures were done at 630 C for 672 hours. The reaction atmosphere, consisting of CO 2 , H 2 O, O 2 , N 2 and SO 2 , was mixed to resemble that of oxy-fuel firing in the first exposure and that of conventional coal firing in the second exposure (N 2 was added during the second exposure only). Four different materials were tested in the first exposure; Sanicro 63, Alloy 800HT, 304L and 304HCu. In the second exposure four different materials were tested; 304L, Alloy 800HT, Kanthal APMT and NiCrAl. Apart from cleaned sample coupons, some samples pre-exposed in a test rig under oxy-fuel conditions with lignite as fuel and some pre-exposed with bituminous coal as fuel were investigated in the first exposure. In the second exposure some samples were pre-exposed in a rig under conventional firing conditions with lignite as fuel. The corrosion attack on the investigated samples was analysed by gravimetry, x-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive x-ray (EDX). The SEM/EDX analysis was made on both the sample envelope and metallographic cross sections of the samples. The results show that there is small difference in the corrosion attack between the two environments. There was also little difference in oxide morphology and composition between cleaned samples and pre-exposed samples of the same material. The austenitic chromia former 304HCu suffered the most extensive corrosion attack in the oxy-fuel environment. In the conventional air firing environment 304L showed the highest mass gain. Chromia formers with higher chromium concentrations performed better, especially the super austenitic Alloy 800HT, with its high chromium concentration, formed a thin and protective corundum type oxide. The nickel based Sanicro 63 showed very low

  17. Focus on the studies in support of fire safety analysis. IRSN modelling approach for nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Espargilliere, Julien; Meyrand, Raphael; Vinot, Thierry [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France)

    2015-12-15

    For a fire safety analysis, in order to comply with nuclear safety goals, a nuclear fuel facility operator has to define the elements important for safety to be maintained, even in the case of a fire. One of the key points of this fire analysis is the assessment of possible fire scenarios in the facility. This paper presents the IRSN method applied to a case study to assess fire scenarios which have the most harmful effects on safety targets. The layout consists in a central room (fire cell) containing three glove boxes with radioactive material and three electrical cabinets. This room is linked to two connecting compartments (the fire cell and these two compartments define the containment cell) and then to two corridors. Each room is equipped with a mechanical ventilation system, and a pressure cascade is established from the corridors to the central room. A fire scenario was studied with fire ignition occurring in an electrical cabinet. This scenario has a set of safety goals (prevention of fire cell and containment device failure, propagation of the fire). This case study was conducted with the IRSN code SYLVIA based on two zones modelling. Safety goals were associated with key parameters and performance criteria to be fulfilled. Modelling assumptions were defined in order to maximize physical effects of the fire. Sensitivity studies were also conducted on key parameters such as oxygen limitation, equivalent-fuel definition. Eventually, a critical analysis of the code models was carried out.

  18. A Revised Historical Fire Regime Analysis in Tunisia (1985–2010 from a Critical Analysis of the National Fire Database and Remote Sensing

    Directory of Open Access Journals (Sweden)

    Chiraz Belhadj-Khedher

    2018-01-01

    Full Text Available Long-term fire history reconstructions provide fruitful information in the context of global change. Global remotely-sensed burned areas offer a uniform estimate of fire regimes worldwide, but hardly capture small fire events and cover only the last 20 years. Burned areas from national statistics often lack credibility due to discrepancies in fire report protocols between countries, partial data records and uncertain burned area estimates from field observations. However, they constitute a unique and valuable alternative long-term key source of information. We provide here a detailed critical analysis of the fire database in Tunisia, on the southern boundary of the Mediterranean basin and with a contrasted socio-economic environment compared to the more studied European side. We analyzed the fire record database with a quality checking protocol, combined with remote sensing burned area characterization from Landsat images. The high uncertainties in fire numbers could not lead to any conclusion for an accurate trend estimate. The corrected burned area lead to an average yearly burned area of 1799 ha year−1 compared to previous estimates of 1017 ha year−1, leading to a fraction of burnable land affected by fires of 0.19%, on the lowest range of observations in the Mediterranean basin. From this corrected database, we revised the usually assumed burned area decrease in this region, with no significant trend detected over the 1985–2010 period. We conclude on the need for thorough assessment of data quality in fire history reconstruction from national statistics to prevent misleading conclusions, and for an increased credibility, in order to be further used in fire models benchmarking or fire weather analysis. Our results can contribute to the under-represented fire regime analysis on the southern boundary of the Mediterranean basin.

  19. Application of fluorescence analysis for evaluation of heat stability of Scotch pine needles after ground fires

    Directory of Open Access Journals (Sweden)

    I. V. Kosov

    2017-10-01

    Full Text Available This paper discusses the possibility of using fluorescent methods to assess the thermal effects on Scots pine needles’ assimilation apparatus. Two types of experimental studies were carried out. The assessment of the primary heat resistance of the needles from the forest stand previously unaffected by fire lies at the heart of the first one. To assess the effect of temperature stress on the pine needles’ photosynthetic apparatus functioning, the experiments on modeling a convective flow, simulating the ground fire effect were carried out. The second year needles from the 1st class trees of the green moss-and-motley group of forest types located in the forest-steppe zone of Southern Siberia were studied. According to Fv / Fm fast fluorescence parameter (the maximum photochemical quantum yield of photosystem II, it was demonstrated that after the heat stress, the assimilation apparatus of pine needles can be restored at different rates. This rate depends on the duration and intensity of heating. The second experiment was based upon the task of determining the ability to restore the assimilation apparatus of pine needles after the repeated influence of sub-lethal temperatures on plants in the recovery period after a ground fire of the previous year. Based on the analysis of the parameters of fast and delayed fluorescence, it was possible to detect differences in thermal resistance and the rates of pine needles’ photosynthetic activity reestablishment, which indicates modification of physiological processes in plants under the influence of the thermal stress factor, forming a positive acclimation effect. Thus, fluorescent methods can be used to diagnose the thermal resistance of needles. In particular, the indicator of delayed fluorescence as a criterion for assessing the resistance of the assimilation apparatus in response to the repeated action of stress factors during the recovery from fire. Fv / Fm ratio can be used to assess the response

  20. Analysis of RHIC beam dump pre-fires

    International Nuclear Information System (INIS)

    Zhang, W.; Ahrens, L.; Fischer, W.; Hahn, H.; Mi, J.; Sandberg, J.; Tan, Y.

    2011-01-01

    It has been speculated that the beam may cause instability of the RHIC Beam Abort Kickers. In this study, we explore the available data of past beam operations, the device history of key modulator components, and the radiation patterns to examine the correlations. The RHIC beam abort kicker system was designed and built in the 90's. Over last decade, we have made many improvements to bring the RHIC beam abort kicker system to a stable operational state. However, the challenge continues. We present the analysis of the pre-fire, an unrequested discharge of kicker, issues which relates to the RHIC machine safety and operational stability.

  1. Modeling of biomass smoke injection into the lower stratosphere by a large forest fire (Part I: reference simulation

    Directory of Open Access Journals (Sweden)

    J. Trentmann

    2006-01-01

    Full Text Available Wildland fires in boreal regions have the potential to initiate deep convection, so-called pyro-convection, due to their release of sensible heat. Under favorable atmospheric conditions, large fires can result in pyro-convection that transports the emissions into the upper troposphere and the lower stratosphere. Here, we present three-dimensional model simulations of the injection of fire emissions into the lower stratosphere by pyro-convection. These model simulations are constrained and evaluated with observations obtained from the Chisholm fire in Alberta, Canada, in 2001. The active tracer high resolution atmospheric model (ATHAM is initialized with observations obtained by radiosonde. Information on the fire forcing is obtained from ground-based observations of the mass and moisture of the burned fuel. Based on radar observations, the pyro-convection reached an altitude of about 13 km, well above the tropopause, which was located at about 11.2 km. The model simulation yields a similarly strong convection with an overshoot of the convection above the tropopause. The main outflow from the pyro-convection occurs at about 10.6 km, but a significant fraction (about 8% of the emitted mass of the smoke aerosol is transported above the tropopause. In contrast to regular convection, the region with maximum updraft velocity in the pyro-convection is located close to the surface above the fire. This results in high updraft velocities >10 m s−1 at cloud base. The temperature anomaly in the plume decreases rapidly with height from values above 50 K at the fire to about 5 K at about 3000 m above the fire. While the sensible heat released from the fire is responsible for the initiation of convection in the model, the release of latent heat from condensation and freezing dominates the overall energy budget. Emissions of water vapor from the fire do not significantly contribute to the energy budget of the convection.

  2. Analysis of biomass co-firing systems in Taiwan power markets using linear complementarity models

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Ming-Che; Lin, Chun-Hung [Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Chou, Chun-An [Department of Industrial and Systems Engineering, Rutgers University, 96 Frelinghuysen Rd, Piscataway, NJ 08854 (United States); Hsu, Shao-Yiu [Department of Geography and Environmental Engineering, Johns Hopkins University, 3400, N Charles St, Ames-313, Baltimore, MD 21218 (United States); Wen, Tzai-Hung, E-mail: wenthung@ntu.edu.tw [Department of Geography, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China)

    2011-08-15

    Biomass co-firing systems in power plants generate electric power by the simultaneous combustion of biomass and fossil fuels. The co-firing process reduces investment costs by converting biomass energy into electricity in existing conventional power plants. Biomass co-firing significantly reduces carbon dioxide and sulfur dioxide emissions in power generation. To meet the increase in biomass demand, this paper has considered systematic energy crop production, which is expected to increase in the near future. Our aim is to analyze biomass co-firing systems in the Taiwanese electricity market. In this paper, we study two emerging biomass feedstocks: switchgrass and Miscanthus. We focus on the impact of energy crop co-firing on carbon dioxide and sulfur dioxide emissions for electricity generation. A Nash-Cournot competition model, which simulates potential biomass co-firing scenarios, is formulated for power markets. A case study conducted in the Taiwanese electricity market showed that biomass co-firing lowers total electricity demand and sale. Miscanthus is more economical than switchgrass in terms of the production cost and the land required to generate biopower for the same levels of biomass co-firing. - Highlights: > Biomass co-firing system in electricity market is analyzed in this paper. > The research studies the impact of two energy crops in co-firing system. > This paper conducts a case study of co-firing system in Taiwan power markets.

  3. Integrating fire behavior models and geospatial analysis for wildland fire risk assessment and fuel management planning

    Science.gov (United States)

    Alan A. Ager; Nicole M. Vaillant; Mark A. Finney

    2011-01-01

    Wildland fire risk assessment and fuel management planning on federal lands in the US are complex problems that require state-of-the-art fire behavior modeling and intensive geospatial analyses. Fuel management is a particularly complicated process where the benefits and potential impacts of fuel treatments must be demonstrated in the context of land management goals...

  4. The Persuasive Power of Virtual Reality: Effects of Simulated Human Distress on Attitudes towards Fire Safety

    Science.gov (United States)

    Chittaro, Luca; Zangrando, Nicola

    Although virtual reality (VR) is a powerful simulation tool that can allow users to experience the effects of their actions in vivid and memorable ways, explorations of VR as a persuasive technology are rare. In this paper, we focus on different ways of providing negative feedback for persuasive purposes through simulated experiences in VR. The persuasive goal we consider concerns awareness of personal fire safety issues and the experiment we describe focuses on attitudes towards smoke in evacuating buildings. We test two techniques: the first technique simulates the damaging effects of smoke on the user through a visualization that should not evoke strong emotions, while the second is aimed at partially reproducing the anxiety of an emergency situation. The results of the study show that the second technique is able to increase user's anxiety as well as producing better results in attitude change.

  5. A spatio-temporal analysis of fires in South Africa

    Directory of Open Access Journals (Sweden)

    Sheldon Strydom

    2016-11-01

    Full Text Available The prevalence and history of fires in Africa has led to the continent being named "the fire continent". Fires are common on the continent and lead to a high number of annual fire disasters which result in many human fatalities and considerable financial loss. Increased population growth and concentrated settlement planning increase the probability of fire disasters and the associated loss of human life and financial loss when disasters occur. In order to better understand the spatial and temporal variations and characteristics of fires in South Africa, an 11-year data set of MODIS-derived Active Fire Hotspots was analysed using an open source geographic information system. The study included the mapping of national fire frequency over the 11-year period. Results indicate that the highest fire frequency occurred in the northeastern regions of South Africa, in particular the mountainous regions of KwaZulu-Natal and Mpumalanga, and in the Western Cape. Increasing trends in provincial fire frequency were observed in eight of the nine provinces of South Africa, with Mpumalanga the only province for which a decrease in annual fire frequency was observed. Temporally, fires were observed in all months for all provinces, although distinct fire seasons were observed and were largely driven by rainfall seasons. The southwestern regions of South Africa (winter-rainfall regions experienced higher fire frequencies during the summer months and the rest of the country (summer-rainfall regions during the winter months. Certain regions those which experienced bimodal rainfall seasons did not display distinct fire seasons because of the complex wet and dry seasons. Investigation into the likely effects of climate change on South African fire frequency revealed that increased air temperatures and events such as La Niña have a marked effect on fire activity.

  6. Safety analysis of the existing 850 Firing Facility

    International Nuclear Information System (INIS)

    Odell, B.N.

    1986-01-01

    A safety analysis was performed to determine if normal operations and/or potential accidents at the 850 Firing Facility at Site 300 could present undue hazards to the general public, personnel at Site 300, or have an adverse effect on the environment. The normal operations and credible accidents that might have an effect on these facilities or have off-site consequences were considered. It was determined by this analysis that all but one of the hazards were either low or of the type or magnitude routinely encountered and/or accepted by the public. The exception was explosives, which was classified as a moderate hazard per the requirements given in DOE Order 5481.1A. This safety analysis concluded that the operation at this facility will present no undue risk to the health and safety of LLNL employees or the public

  7. Safety analysis of the existing 851 Firing Facility

    International Nuclear Information System (INIS)

    Odell, B.N.

    1986-01-01

    A safety analysis was performed to determine if normal operations and/or potential accidents at the 851 Firing Facility at Site 300 could present undue hazards to the general public, personnel at Site 300, or have an adverse effect on the environment. The normal operations and credible accidents that might have an effect on these facilities or have off-site consequences were considered. It was determined by this analysis that all but two of the hazards were either low or of the type or magnitude routinely encountered and/or accepted by the public. The exceptions were the linear accelerator and explosives, which were classified as moderate hazards per the requirements given in DOE Order 5481.1A. This safety analysis concluded that the operation at this facility will present no undue risk to the health and safety of LLNL employees or the public

  8. Thermal analysis of two-dimensional structures in fire

    Directory of Open Access Journals (Sweden)

    I. Pierin

    Full Text Available The structural materials, as reinforced concrete, steel, wood and aluminum, when heated have their mechanical proprieties degraded. In fire, the structures are subject to elevated temperatures and consequently the load capacity of the structural elements is reduced. The Brazilian and European standards show the minimal dimensions for the structural elements had an adequate bearing capacity in fire. However, several structural checks are not contemplated in methods provided by the standards. In these situations, the knowledge of the temperature distributions inside of structural elements as function of time of exposition is required. The aim of this paper is present software developed by the authors called ATERM. The software performs the thermal transient analysis of two-dimensional structures. The structure may be formed of any material and heating is provided by means of a curve of temperature versus time. The data input and the visualization of the results is performed thought the GiD software. Several examples are compared with software Super TempCalc and ANSYS. Some conclusions and recommendations about the thermal analysis are presented

  9. FRANX. Application for analysis and quantification of the APS fire

    International Nuclear Information System (INIS)

    Snchez, A.; Osorio, F.; Ontoso, N.

    2014-01-01

    The FRANX application has been developed by EPRI within the Risk and Reliability User Group in order to facilitate the process of quantification and updating APS Fire (also covers floods and earthquakes). By applying fire scenarios are quantified in the central integrating the tasks performed during the APS fire. This paper describes the main features of the program to allow quantification of an APS Fire. (Author)

  10. Reducing the computational requirements for simulating tunnel fires by combining multiscale modelling and multiple processor calculation

    DEFF Research Database (Denmark)

    Vermesi, Izabella; Rein, Guillermo; Colella, Francesco

    2017-01-01

    in FDS version 6.0, a widely used fire-specific, open source CFD software. Furthermore, it compares the reduction in simulation time given by multiscale modelling with the one given by the use of multiple processor calculation. This was done using a 1200m long tunnel with a rectangular cross...... processor calculation (97% faster when using a single mesh and multiscale modelling; only 46% faster when using the full tunnel and multiple meshes). In summary, it was found that multiscale modelling with FDS v.6.0 is feasible, and the combination of multiple meshes and multiscale modelling was established...

  11. Fire data analysis and feature reduction using computational intelligence methods

    NARCIS (Netherlands)

    Bahrepour, M.; van der Zwaag, B.J.; Meratnia, Nirvana; Havinga, Paul J.M.; Phillips-Wren, G.; Jain, L.C.; Nakamatsu, K.

    2010-01-01

    Fire is basically the fast oxidation of a substance that produces gases and chemical productions. These chemical productions can be read by sensors to yield an insight about type and place of the fire. However, as fires may occur in indoor or outdoor areas, the type of gases and therefore sensor

  12. Simulation analysis of a wildfire suppression system

    Science.gov (United States)

    Abílio Pereira Pacheco; João Claro; Tiago. Oliveira

    2013-01-01

    Rekindles and false alarms are unusually high in the Portuguese wildfire management system, representing a high burden on suppression resources in particular, and fire management resources in general. In 20,049 occurrences that the suppression system handled in the summer of 2010, 12.5% were false alarms and 15.0% were rekindles. We present a discreteevent simulation...

  13. Boreal forest fires in 1997 and 1998: a seasonal comparison using transport model simulations and measurement data

    Directory of Open Access Journals (Sweden)

    N. Spichtinger

    2004-01-01

    Full Text Available Forest fire emissions have a strong impact on the concentrations of trace gases and aerosols in the atmosphere. In order to quantify the influence of boreal forest fire emissions on the atmospheric composition, the fire seasons of 1997 and 1998 are compared in this paper. Fire activity in 1998 was very strong, especially over Canada and Eastern Siberia, whereas it was much weaker in 1997. According to burned area estimates the burning in 1998 was more than six times as intense as in 1997. Based on hot spot locations derived from ATSR (Along Track Scanning Radiometer data and official burned area data, fire emissions were estimated and their transport was simulated with a Lagrangian tracer transport model. Siberian and Canadian forest fire tracers were distinguished to investigate the transport of both separately. The fire emissions were transported even over intercontinental distances. Due to the El Niño induced meteorological situation, transport from Siberia to Canada was enhanced in 1998. Siberian fire emissions were transported towards Canada and contributed concentrations more than twice as high as those due to Canada's own CO emissions by fires. In 1998 both tracers arrive at higher latitudes over Europe, which is due to a higher North Atlantic Oscillation (NAO index in 1998. The simulated emission plumes are compared to CMDL (Climate Monitoring and Diagnostics Laboratory CO2 and CO data, Total Ozone Mapping Spectrometer (TOMS aerosol index (AI data and Global Ozone Monitoring Experiment (GOME tropospheric NO2 and HCHO columns. All the data show clearly enhanced signals during the burning season of 1998 compared to 1997. The results of the model simulation are in good agreement with ground-based as well as satellite-based measurements.

  14. Simulating the Effects of Fire on Forests in the Russian Far East: Integrating a Fire Danger Model and the FAREAST Forest Growth Model Across a Complex Landscape

    Science.gov (United States)

    Sherman, N. J.; Loboda, T.; Sun, G.; Shugart, H. H.; Csiszar, I.

    2008-12-01

    The remaining natural habitat of the critically endangered Amur tiger (Panthera tigris altaica) and Amur leopard (Panthera pardus orientalis) is a vast, biologically and topographically diverse area in the Russian Far East (RFE). Although wildland fire is a natural component of ecosystem functioning in the RFE, severe or repeated fires frequently re-set the process of forest succession, which may take centuries to return the affected forests to the pre-fire state and thus significantly alters habitat quality and long-term availability. The frequency of severe fire events has increased over the last 25 years, leading to irreversible modifications of some parts of the species' habitats. Moreover, fire regimes are expected to continue to change toward more frequent and severe events under the influence of climate change. Here we present an approach to developing capabilities for a comprehensive assessment of potential Amur tiger and leopard habitat availability throughout the 21st century by integrating regionally parameterized fire danger and forest growth models. The FAREAST model is an individual, gap-based model that simulates forest growth in a single location and demonstrates temporally explicit forest succession leading to mature forests. Including spatially explicit information on probabilities of fire occurrence at 1 km resolution developed from the regionally specific remotely -sensed data-driven fire danger model improves our ability to provide realistic long-term projections of potential forest composition in the RFE. This work presents the first attempt to merge the FAREAST model with a fire disturbance model, to validate its outputs across a large region, and to compare it to remotely-sensed data products as well as in situ assessments of forest structure. We ran the FAREAST model at 1,000 randomly selected points within forested areas in the RFE. At each point, the model was calibrated for temperature, precipitation, slope, elevation, and fire

  15. A Case Study of Two Computer Methods Used to Simulate Fires in Industrial Facilities

    National Research Council Canada - National Science Library

    Asselta, Christopher

    1997-01-01

    .... The arrangement of decaying organic matter may have been enough to generate a small fire. Conventional anthropologists argue that fire may have been first discovered in forest fires started by lightning, lava flows or other natural causes...

  16. Wildland fire management. Volume 1: Prevention methods and analysis. [systems engineering approach to California fire problems

    Science.gov (United States)

    Weissenberger, S. (Editor)

    1973-01-01

    A systems engineering approach is reported for the problem of reducing the number and severity of California's wildlife fires. Prevention methodologies are reviewed and cost benefit models are developed for making preignition decisions.

  17. Motorcoach fire safety analysis : the causes, frequency, and severity of motorcoach fires in the United States

    Science.gov (United States)

    2012-06-28

    The Federal Motor Carrier Safety Administrations (FMCSA) mission is to reduce crashes, injuries, and fatalities on our nations roads involving motor vehicles, and to further its work the agency set out to identify ways to reduce motorcoach fire...

  18. Trend analysis of fire events at nuclear power plants

    International Nuclear Information System (INIS)

    Shimada, Hiroki

    2007-01-01

    We performed trend analyses to compare fire events occurring overseas (1995-2005) and in Japan (1966-2006). We decided to do this after extracting data on incidents (storms, heavy rain, tsunamis, fires, etc.) occurring at overseas nuclear power plants from the Events Occurred at Overseas Nuclear Power Plants recorded in the Nuclear Information Database at the Institute of Nuclear Safety System (INSS) and finding that fires were the most common of the incidents. Analyses compared the number of fires occurring domestically and overseas and analyzed their causes and the effect of the fires on the power plants. As a result, we found that electrical fires caused by such things as current overheating and electric arcing, account for over one half of the domestic and overseas incidents of fire, which indicates that maintenance management of electric facilities is the most important aspect of fire prevention. Also, roughly the same number of operational fires occurred at domestic and overseas plants, judging from the figures for annual occurrences per unit. However, the overall number of fires per unit at domestic facilities is one fourth that of overseas facilities. We surmise that, while management of operations that utilizes fire is comparable for overseas and domestic plants, this disparity results from differences in the way maintenance is carried out at facilities. (author)

  19. On the characterization of vegetation recovery after fire disturbance using Fisher-Shannon analysis and SPOT/VEGETATION Normalized Difference Vegetation Index (NDVI) time series

    Science.gov (United States)

    Lasaponara, Rosa; Lanorte, Antonio; Lovallo, Michele; Telesca, Luciano

    2015-04-01

    characterize vegetation recovery after fire disturbanceInternational Journal of Applied Earth Observation and Geoinformation 26 441-446 Lanorte A, M Danese, R Lasaponara, B Murgante 2014 Multiscale mapping of burn area and severity using multisensor satellite data and spatial autocorrelation analysis International Journal of Applied Earth Observation and Geoinformation 20, 42-51 Tuia D, F Ratle, R Lasaponara, L Telesca, M Kanevski 2008 Scan statistics analysis of forest fire clusters Communications in Nonlinear Science and Numerical Simulation 13 (8), 1689-1694 Telesca L, R Lasaponara 2006 Pre and post fire behavioral trends revealed in satellite NDVI time series Geophysical Research Letters 33 (14) Lasaponara R 2005 Intercomparison of AVHRR based fire susceptibility indicators for the Mediterranean ecosystems of southern Italy International Journal of Remote Sensing 26 (5), 853-870

  20. Analysis of the tropospheric water distribution during FIRE 2

    Science.gov (United States)

    Westphal, Douglas L.

    1993-01-01

    The Penn State/NCAR mesoscale model, as adapted for use at ARC, was used as a testbed for the development and validation of cloud models for use in General Circulation Models (GCM's). This modeling approach also allows us to intercompare the predictions of the various cloud schemes within the same dynamical framework. The use of the PSU/NCAR mesoscale model also allows us to compare our results with FIRE-II (First International Satellite Cloud Climatology Project Regional Experiment) observations, instead of climate statistics. Though a promising approach, our work to date revealed several difficulties. First, the model by design is limited in spatial coverage and is only run for 12 to 48 hours at a time. Hence the quality of the simulation will depend heavily on the initial conditions. The poor quality of upper-tropospheric measurements of water vapor is well known and the situation is particularly bad for mid-latitude winter since the coupling with the surface is less direct than in summer so that relying on the model to spin-up a reasonable moisture field is not always successful. Though one of the most common atmospheric constituents, water vapor is relatively difficult to measure accurately, especially operationally over large areas. The standard NWS sondes have little sensitivity at the low temperatures where cirrus form and the data from the GOES 6.7 micron channel is difficult to quantify. For this reason, the goals of FIRE Cirrus II included characterizing the three-dimensional distribution of water vapor and clouds. In studying the data from FIRE Cirrus II, it was found that no single special observation technique provides accurate regional distributions of water vapor. The Raman lidar provides accurate measurements, but only at the Hub, for levels up to 10 km, and during nighttime hours. The CLASS sondes are more sensitive to moisture at low temperatures than are the NWS sondes, but the four stations only cover an area of two hundred kilometers on a side

  1. Gas Kinematics in FIRE Simulated Galaxies Compared to Spatially Unresolved HI Observations

    Science.gov (United States)

    El-Badry, Kareem; Bradford, Jeremy; Quataert, Eliot; Geha, Marla; Boylan-Kolchin, Michael; Weisz, Daniel R.; Wetzel, Andrew; Hopkins, Philip F.; K Chan, T.; Fitts, Alex; Kereš, Dušan; Faucher-Giguère, Claude-André

    2018-03-01

    The shape of a galaxy's spatially unresolved, globally integrated 21-cm emission line depends on its internal gas kinematics: galaxies with rotation-supported gas disks produce double-horned profiles with steep wings, while galaxies with dispersion-supported gas produce Gaussian-like profiles with sloped wings. Using mock observations of simulated galaxies from the FIRE project, we show that one can therefore constrain a galaxy's gas kinematics from its unresolved 21-cm line profile. In particular, we find that the kurtosis of the 21-cm line increases with decreasing V/σ, and that this trend is robust across a wide range of masses, signal-to-noise ratios, and inclinations. We then quantify the shapes of 21-cm line profiles from a morphologically unbiased sample of ˜2000 low-redshift, HI-detected galaxies with Mstar = 107 - 11M⊙ and compare to the simulated galaxies. At Mstar ≳ 1010M⊙, both the observed and simulated galaxies produce double-horned profiles with low kurtosis and steep wings, consistent with rotation-supported disks. Both the observed and simulated line profiles become more Gaussian-like (higher kurtosis and less-steep wings) at lower masses, indicating increased dispersion support. However, the simulated galaxies transition from rotation to dispersion support more strongly: at Mstar = 108 - 10M⊙, most of the simulations produce more Gaussian-like profiles than typical observed galaxies with similar mass, indicating that gas in the low-mass simulated galaxies is, on average, overly dispersion-supported. Most of the lower-mass simulated galaxies also have somewhat lower gas fractions than the median of the observed population. The simulations nevertheless reproduce the observed line-width baryonic Tully-Fisher relation, which is insensitive to rotation vs. dispersion support.

  2. Sensitivity Analysis of Simulation Models

    NARCIS (Netherlands)

    Kleijnen, J.P.C.

    2009-01-01

    This contribution presents an overview of sensitivity analysis of simulation models, including the estimation of gradients. It covers classic designs and their corresponding (meta)models; namely, resolution-III designs including fractional-factorial two-level designs for first-order polynomial

  3. Flame spread monitoring and estimation of the heat release rate from a cable tray fire using Video Fire Analysis (VFA)

    OpenAIRE

    Beji, Tarek; Merci, Bart; Verstockt, Steven; Zavaleta, Pascal

    2016-01-01

    The paper presents an application of video fire analysis (VFA) to a cable tray fire scenario, a scenario of interest to nuclear power plants where cables constitute a substantial part of the combustible load. Five horizontal trays, each 2.4 m long and 0.45 m wide, are positioned with a 0.3 m spacing (in the vertical direction) and set-up against an insulated wall. Each tray contains 49 power PVC cables of 13 mm outer diameter. Ignition is performed with an 80 kW propane burner centrally posit...

  4. Validation of CFD simulation of recoilless EOD water cannon by firing experiments with high speed camera

    Science.gov (United States)

    Chantrasmi, Tonkid; Hongthong, Premsiri; Kongkaniti, Manop

    2018-01-01

    Water cannon used by Explosive Ordnance Disposal (EOD) were designed to propel a burst of water jet moving at high speed to target and disrupt an improvised explosive device (IED). The cannon could be mounted on a remotely controlled robot, so it is highly desirable for the cannon to be recoilless in order not to damage the robot after firing. In the previous work, a nonconventional design of the water cannon was conceived. The recoil was greatly reduced by backward sprays of water through a ring of slotted holes around the muzzle. This minimizes the need to manufacture new parts by utilizing all off-the-shelf components except the tailor-made muzzle. The design was then investigated numerically by a series of Computational Fluid Dynamics (CFD) simulations. In this work, high speed camera was employed in firing experiments to capture the motion of the water jet and the backward sprays. It was found that the experimental data agreed well with the simulation results in term of averaged exit velocities.

  5. Numerical validation of selected computer programs in nonlinear analysis of steel frame exposed to fire

    Science.gov (United States)

    Maślak, Mariusz; Pazdanowski, Michał; Woźniczka, Piotr

    2018-01-01

    Validation of fire resistance for the same steel frame bearing structure is performed here using three different numerical models, i.e. a bar one prepared in the SAFIR environment, and two 3D models developed within the framework of Autodesk Simulation Mechanical (ASM) and an alternative one developed in the environment of the Abaqus code. The results of the computer simulations performed are compared with the experimental results obtained previously, in a laboratory fire test, on a structure having the same characteristics and subjected to the same heating regimen. Comparison of the experimental and numerically determined displacement evolution paths for selected nodes of the considered frame during the simulated fire exposure constitutes the basic criterion applied to evaluate the validity of the numerical results obtained. The experimental and numerically determined estimates of critical temperature specific to the considered frame and related to the limit state of bearing capacity in fire have been verified as well.

  6. Simulating Fire Disturbance and Plant Mortality Using Antecedent Eco-hydrological Conditions to Inform a Physically Based Combustion Model

    Science.gov (United States)

    Atchley, A. L.; Linn, R.; Middleton, R. S.; Runde, I.; Coon, E.; Michaletz, S. T.

    2016-12-01

    Wildfire is a complex agent of change that both affects and depends on eco-hydrological systems, thereby constituting a tightly linked system of disturbances and eco-hydrological conditions. For example, structure, build-up, and moisture content of fuel are dependent on eco-hydrological regimes, which impacts fire spread and intensity. Fire behavior, on the other hand, determines the severity and extent of eco-hydrological disturbance, often resulting in a mosaic of untouched, stressed, damaged, or completely destroyed vegetation within the fire perimeter. This in turn drives new eco-hydrological system behavior. The cycles of disturbance and recovery present a complex evolving system with many unknowns especially in the face of climate change that has implications for fire risk, water supply, and forest composition. Physically-based numerical experiments that attempt to capture the complex linkages between eco-hydrological regimes that affect fire behavior and the echo-hydrological response from those fire disturbances help build the understanding required to project how fire disturbance and eco-hydrological conditions coevolve over time. Here we explore the use of FIRETEC—a physically-based 3D combustion model that solves conservation of mass, momentum, energy, and chemical species—to resolve fire spread over complex terrain and fuel structures. Uniquely, we couple a physically-based plant mortality model with FIRETEC and examine the resultant hydrologic impact. In this proof of concept demonstration we spatially distribute fuel structure and moisture content based on the eco-hydrological condition to use as input for FIRETEC. The fire behavior simulation then produces localized burn severity and heat injures which are used as input to a spatially-informed plant mortality model. Ultimately we demonstrate the applicability of physically-based models to explore integrated disturbance and eco-hydrologic response to wildfire behavior and specifically map how fire

  7. Some insights from fire risk analysis of US nuclear power plants

    International Nuclear Information System (INIS)

    Kazarians, M.; Lambright, J.A.; Frank, M.V.

    1998-01-01

    Fire risk analysis has been conducted for a significant portion of the nuclear power plants in the U.S. using either Probabilistic Risk Assessments (PRAs) or FIVE or a combination of the two methodologies. Practically all fire risk studies have used step-wise, screening approach. To establish the contents of a compartment, the cable routing information collected for Appendix R compliance have been used in practically all risk studies. In several cases, the analysts have gone beyond the Appendix R and have obtained the routing of additional cables. For fire impact analysis typically an existing PRA model is used. For fire frequencies, typically, a generic data base is used. Fire scenarios are identified in varying levels of detail. The most common approach, in the early stages of screening, is based on the assumption that given a fire, the entire contents of the compartment are lost. Less conservative scenarios are introduced at later stages of the analysis which may include fire propagation patterns, fires localized to an item. and suppression of the fire before critical damage. For fire propagation and damage analysis, a large number of studies have used FIVE and many have used COMPBRN. For detection and suppression analysis, the generic suppression system unavailabilities given in FIVE have been used. The total core damage frequencies typically range between 1x10 -6 to 1x10 -4 per year. Control rooms and cable spreading rooms are the two most common areas found to be significant contributors to fire risk. Other areas are mainly from the Auxiliary Building (in the case of PWRs) and Reactor Building (in the case of BWRs). Only in one case, the main contributor to fire is the turbine building, which included several safety related equipment and cables. (author)

  8. Examination of Wildland Fire Spread at Small Scales Using Direct Numerical Simulations and High-Speed Laser Diagnostics

    Science.gov (United States)

    Wimer, N. T.; Mackoweicki, A. S.; Poludnenko, A. Y.; Hoffman, C.; Daily, J. W.; Rieker, G. B.; Hamlington, P.

    2017-12-01

    Results are presented from a joint computational and experimental research effort focused on understanding and characterizing wildland fire spread at small scales (roughly 1m-1mm) using direct numerical simulations (DNS) with chemical kinetics mechanisms that have been calibrated using data from high-speed laser diagnostics. The simulations are intended to directly resolve, with high physical accuracy, all small-scale fluid dynamic and chemical processes relevant to wildland fire spread. The high fidelity of the simulations is enabled by the calibration and validation of DNS sub-models using data from high-speed laser diagnostics. These diagnostics have the capability to measure temperature and chemical species concentrations, and are used here to characterize evaporation and pyrolysis processes in wildland fuels subjected to an external radiation source. The chemical kinetics code CHEMKIN-PRO is used to study and reduce complex reaction mechanisms for water removal, pyrolysis, and gas phase combustion during solid biomass burning. Simulations are then presented for a gaseous pool fire coupled with the resulting multi-step chemical reaction mechanisms, and the results are connected to the fundamental structure and spread of wildland fires. It is anticipated that the combined computational and experimental approach of this research effort will provide unprecedented access to information about chemical species, temperature, and turbulence during the entire pyrolysis, evaporation, ignition, and combustion process, thereby permitting more complete understanding of the physics that must be represented by coarse-scale numerical models of wildland fire spread.

  9. Analysis of accelerants and fire debris using aroma detection technology

    Energy Technology Data Exchange (ETDEWEB)

    Barshick, S.A.

    1997-01-17

    The purpose of this work was to investigate the utility of electronic aroma detection technologies for the detection and identification of accelerant residues in suspected arson debris. Through the analysis of known accelerant residues, a trained neural network was developed for classifying suspected arson samples. Three unknown fire debris samples were classified using this neural network. The item corresponding to diesel fuel was correctly identified every time. For the other two items, wide variations in sample concentration and excessive water content, producing high sample humidities, were shown to influence the sensor response. Sorbent sampling prior to aroma detection was demonstrated to reduce these problems and to allow proper neural network classification of the remaining items corresponding to kerosene and gasoline.

  10. Fire behavior simulation in Mediterranean forests using the minimum travel time algorithm

    Science.gov (United States)

    Kostas Kalabokidis; Palaiologos Palaiologou; Mark A. Finney

    2014-01-01

    Recent large wildfires in Greece exemplify the need for pre-fire burn probability assessment and possible landscape fire flow estimation to enhance fire planning and resource allocation. The Minimum Travel Time (MTT) algorithm, incorporated as FlamMap's version five module, provide valuable fire behavior functions, while enabling multi-core utilization for the...

  11. Integrating landscape and hydrologic simulation models to assess the influence of fire-suppression on water yield from forested Rocky Mountain watersheds

    Science.gov (United States)

    Ahl, R. S.; Woods, S.; Diluzio, M.

    2005-12-01

    Most of the water supply for semi-arid western North America originates as snow that is deposited and temporarily stored in forested, high elevation watersheds. Snow accumulation in these watersheds varies with climate, elevation, topography and forest vegetation characteristics. Canopy structure is an especially important vegetation characteristic because of its effect on the interception component of the water budget and the wind speed and solar radiation flux at the snow surface. Canopy structure is a function of forest composition, structure and extent, all of which are shaped by disturbance processes such as fire, insect and disease outbreaks, and human-induced changes. Changes in the frequency and magnitude of these disturbance processes such as those that have occurred due to fire suppression lead to changes in forest structure, and this may result in long term reductions in water yield from forested watersheds. We have developed a methodology for linking, spatially explicit, time-series, landcover and hydrologic analysis at the watershed scale, with the goal of quantifying changes in long term water yield due to fire suppression and other management scenarios. Output from the SIMPPLLE (Simulating Patterns and Processes at Landscape Scales) vegetation simulation model is classified and processed to provide input to the SWAT (Soil and Water Assessment Tool) hydrologic model. SIMPPLLE integrates various data sources to simulate vegetation growth and disturbance pathways for forested environments in the Rocky Mountains. We used SIMPPLLE to simulate landcover change 300 years forward from current conditions for 1) fire suppression and 2) natural succession management scenarios. Grid-based maps were produced for each scenario at decadal intervals and used as input for SWAT. SWAT was calibrated using current landcover data and five years of daily streamflow records, and a Nash-Sutcliffe model efficiency of 0.90 was achieved. The calibrated SWAT model was then used

  12. The practical implementation of integrated safety management for nuclear safety analysis and fire hazards analysis documentation

    International Nuclear Information System (INIS)

    COLLOPY, M.T.

    1999-01-01

    In 1995 Mr. Joseph DiNunno of the Defense Nuclear Facilities Safety Board issued an approach to describe the concept of an integrated safety management program which incorporates hazard and safety analysis to address a multitude of hazards affecting the public, worker, property, and the environment. Since then the U S . Department of Energy (DOE) has adopted a policy to systematically integrate safety into management and work practices at all levels so that missions can be completed while protecting the public, worker, and the environment. While the DOE and its contractors possessed a variety of processes for analyzing fire hazards at a facility, activity, and job; the outcome and assumptions of these processes have not always been consistent for similar types of hazards within the safety analysis and the fire hazard analysis. Although the safety analysis and the fire hazard analysis are driven by different DOE Orders and requirements, these analyses should not be entirely independent and their preparation should be integrated to ensure consistency of assumptions, consequences, design considerations, and other controls. Under the DOE policy to implement an integrated safety management system, identification of hazards must be evaluated and agreed upon to ensure that the public. the workers. and the environment are protected from adverse consequences. The DOE program and contractor management need a uniform, up-to-date reference with which to plan. budget, and manage nuclear programs. It is crucial that DOE understand the hazards and risks necessarily to authorize the work needed to be performed. If integrated safety management is not incorporated into the preparation of the safety analysis and the fire hazard analysis, inconsistencies between assumptions, consequences, design considerations, and controls may occur that affect safety. Furthermore, confusion created by inconsistencies may occur in the DOE process to grant authorization of the work. In accordance with

  13. ANALYSIS OF EFFICIENCY OF FIRE DANGER INDICES IN FOREST FIRE PREDICTION

    Directory of Open Access Journals (Sweden)

    Fillipe Tamiozzo Pereira Torres

    Full Text Available ABSTRACT Despite the existence of different fire danger indices, the use of an inefficient index can lead to making wrong decisions on the appropriate procedures for preventing and fighting forest fires, while a trusted prediction index can help the most quantification and allocation of resources for prevention. Thereat, the objective of this study is to analyze the efficiency of Fire Weather Index (FWI, Logarithmic of Telicyn Index, Nesterov Index, cumulative indexes of precipitation - evaporation (P-EVAP and evaporation / precipitation (EVAP/P, Monte Alegre Index (FMA and Monte Alegre Changed Index (FMA+ in the prediction of forest fires for the city of Viçosa (MG. The indices were compared using the method known as Skill Score (SS taking into account the days that the indexes pointed to the risk of events with focus fire identified by satellite images on the 01/01/2005 to 31/12/2014 period. According to the results, the Logarithm of Telicyn Index (0.53257 as the most efficient for the study area, followed by the indices EVAP/P (0.46553, P-EVAP (0.43724, Nesterov (0.40445, FWI (0.39213, FMA+(0.34595 and FMA (0.28982.

  14. Assessment of dermal hazard from acid burns with fire retardant garments in a full-size simulation of an engulfment flash fire.

    Science.gov (United States)

    Mackay, Christopher E; Vivanco, Stephanie N; Yeboah, George; Vercellone, Jeff

    2016-09-01

    There have been concerns that fire-derived acid gases could aggravate thermal burns for individuals wearing synthetic flame retardant garments. A comparative risk assessment was performed on three commercial flame retardant materials with regard to relative hazards associated with acidic combustion gases to skin during a full engulfment flash fire event. The tests were performed in accordance with ASTM F1930 and ISO 13506: Standard Test Method for Evaluation of Flame Resistant Clothing for Protection against Fire Simulations Using an Instrumented Manikin. Three fire retardant textiles were tested: an FR treated cotton/nylon blend, a low Protex(®) modacrylic blend, and a medium Protex(®) modacrylic blend. The materials, in the form of whole body coveralls, were subjected to propane-fired flash conditions of 84kW/m(2) in a full sized simulator for a duration of either 3 or 4s. Ion traps consisting of wetted sodium carbonate-impregnated cellulose in Teflon holders were placed on the chest and back both above and under the standard undergarments. The ion traps remained in position from the time of ignition until 5min post ignition. Results indicated that acid deposition did increase with modacrylic content from 0.9μmol/cm(2) for the cotton/nylon, to 12μmol/cm(2) for the medium modacrylic blend. The source of the acidity was dominated by hydrogen chloride. Discoloration was inversely proportional to the amount of acid collected on the traps. A risk assessment was performed on the potential adverse impact of acid gases on both the skin and open wounds. The results indicated that the deposition and dissolution of the acid gases in surficial fluid media (perspiration and blood plasma) resulted in an increase in acidity, but not sufficient to induce irritation/skin corrosion or to cause necrosis in open third degree burns. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Application of wildfire simulation models for risk analysis

    Science.gov (United States)

    Alan A. Ager; Mark A. Finney

    2009-01-01

    Wildfire simulation models are being widely used by fire and fuels specialists in the U.S. to support tactical and strategic decisions related to the mitigation of wildfire risk. Much of this application has resulted from the development of a minimum travel time (MTT) fire spread algorithm (M. Finney) that makes it computationally feasible to simulate thousands of...

  16. Identifying and tracking simulated synaptic inputs from neuronal firing: insights from in vitro experiments.

    Directory of Open Access Journals (Sweden)

    Maxim Volgushev

    2015-03-01

    Full Text Available Accurately describing synaptic interactions between neurons and how interactions change over time are key challenges for systems neuroscience. Although intracellular electrophysiology is a powerful tool for studying synaptic integration and plasticity, it is limited by the small number of neurons that can be recorded simultaneously in vitro and by the technical difficulty of intracellular recording in vivo. One way around these difficulties may be to use large-scale extracellular recording of spike trains and apply statistical methods to model and infer functional connections between neurons. These techniques have the potential to reveal large-scale connectivity structure based on the spike timing alone. However, the interpretation of functional connectivity is often approximate, since only a small fraction of presynaptic inputs are typically observed. Here we use in vitro current injection in layer 2/3 pyramidal neurons to validate methods for inferring functional connectivity in a setting where input to the neuron is controlled. In experiments with partially-defined input, we inject a single simulated input with known amplitude on a background of fluctuating noise. In a fully-defined input paradigm, we then control the synaptic weights and timing of many simulated presynaptic neurons. By analyzing the firing of neurons in response to these artificial inputs, we ask 1 How does functional connectivity inferred from spikes relate to simulated synaptic input? and 2 What are the limitations of connectivity inference? We find that individual current-based synaptic inputs are detectable over a broad range of amplitudes and conditions. Detectability depends on input amplitude and output firing rate, and excitatory inputs are detected more readily than inhibitory. Moreover, as we model increasing numbers of presynaptic inputs, we are able to estimate connection strengths more accurately and detect the presence of connections more quickly. These results

  17. Exergy Analysis of Operating Lignite Fired Thermal Power Plant

    Directory of Open Access Journals (Sweden)

    K. Murugesan

    2009-01-01

    Full Text Available The energy assessment must be made through the energy quantity as well as the quality. But the usual energy analysisevaluates the energy generally on its quantity only. However, the exergy analysis assesses the energy on quantity as well asthe quality. The aim of the exergy analysis is to identify the magnitudes and the locations of real energy losses, in order toimprove the existing systems, processes or components. The present paper deals with an exergy analysis performed on anoperating 50MWe unit of lignite fired steam power plant at Thermal Power Station-I, Neyveli Lignite Corporation Limited,Neyveli, Tamil Nadu, India. The exergy losses occurred in the various subsystems of the plant and their components havebeen calculated using the mass, energy and exergy balance equations. The distribution of the exergy losses in several plantcomponents during the real time plant running conditions has been assessed to locate the process irreversibility. The Firstlaw efficiency (energy efficiency and the Second law efficiency (exergy efficiency of the plant have also been calculated.The comparison between the energy losses and the exergy losses of the individual components of the plant shows that themaximum energy losses of 39% occur in the condenser, whereas the maximum exergy losses of 42.73% occur in the combustor.The real losses of energy which has a scope for the improvement are given as maximum exergy losses that occurredin the combustor.

  18. Safety analysis of the existing 804 and 845 firing facilities

    International Nuclear Information System (INIS)

    Odell, B.N.

    1986-01-01

    A safety analysis was performed to determine if normal operations and/or potential accidents at the 804 and 845 Firing Facilities at Site 300 could present undue hazards to the general public, peronnel at Site 300, or have an adverse effect on the environment. The normal operation and credible accident that might have an effect on these facilities or have off-site consequence were considered. It was determined by this analysis that all but one of the hazards were either low or of the type or magnitude routinely encountered and/or accepted by the public. The exception was explosives. Since this hazard has the potential for causing significant on-site and minimum off-site consequences, Bunkers 804 and 845 have been classified as moderate hazard facilties per DOE Order 5481.1A. This safety analysis concluded that the operation at these facilities will present no undue risk to the health and safety of LLNL employees or the public

  19. Computer-simulation study on fire behaviour in the ventilated cavity of ventilated façade systems

    Directory of Open Access Journals (Sweden)

    Giraldo María P.

    2013-11-01

    Full Text Available Fire spread through the façades is widely recognized as one of the fastest pathways of fire spreading in the buildings. Fire may spread through the façade in different ways depending on the type of façade system and on the elements and materials from which it is constructed. Ventilated façades are multilayer systems whose main feature is the creation of an air chamber of circulating air between the original building wall and the external cladding. The “chimney effect” in the air cavity is a mechanism that improves the façade's thermal behaviour and avoids the appearance of moisture from rain or condensation. However, in a event of fire, it may contribute to the quickest spreading of fire, representing a significant risk to the upper floors of a building. This study deals with some aspects of fire propagation through the ventilated cavity in ventilated façade systems. Also we review the provisions stipulated by the Spanish building code (Código Técnico de la Edificación, CTE [1] to avoid fire spread outside the building. The results highlight the importance of the use of proper fire barriers to ensure the compartmentalization of the ventilated cavity, as well as the use of non-combustible thermal insulation materials, among others. In addition, based on the results, it might be considered that the measures stipulated by the CTE are insufficient to limit the risks associated with this kind of façades systems. The study has been performed using field models of computational fluid-dynamics. In particular, the Fire Dynamics Simulator (FDS software has been used to numerically solve the mathematical integration models.

  20. Simulating boreal forest carbon dynamics after stand-replacing fire disturbance: insights from a global process-based vegetation model

    Science.gov (United States)

    Yue, C.; Ciais, P.; Luyssaert, S.; Cadule, P.; Harden, J.; Randerson, J.; Bellassen, V.; Wang, T.; Piao, S.L.; Poulter, B.; Viovy, N.

    2013-01-01

    Stand-replacing fires are the dominant fire type in North American boreal forests. They leave a historical legacy of a mosaic landscape of different aged forest cohorts. This forest age dynamics must be included in vegetation models to accurately quantify the role of fire in the historical and current regional forest carbon balance. The present study adapted the global process-based vegetation model ORCHIDEE to simulate the CO2 emissions from boreal forest fire and the subsequent recovery after a stand-replacing fire; the model represents postfire new cohort establishment, forest stand structure and the self-thinning process. Simulation results are evaluated against observations of three clusters of postfire forest chronosequences in Canada and Alaska. The variables evaluated include: fire carbon emissions, CO2 fluxes (gross primary production, total ecosystem respiration and net ecosystem exchange), leaf area index, and biometric measurements (aboveground biomass carbon, forest floor carbon, woody debris carbon, stand individual density, stand basal area, and mean diameter at breast height). When forced by local climate and the atmospheric CO2 history at each chronosequence site, the model simulations generally match the observed CO2 fluxes and carbon stock data well, with model-measurement mean square root of deviation comparable with the measurement accuracy (for CO2 flux ~100 g C m−2 yr−1, for biomass carbon ~1000 g C m−2 and for soil carbon ~2000 g C m−2). We find that the current postfire forest carbon sink at the evaluation sites, as observed by chronosequence methods, is mainly due to a combination of historical CO2 increase and forest succession. Climate change and variability during this period offsets some of these expected carbon gains. The negative impacts of climate were a likely consequence of increasing water stress caused by significant temperature increases that were not matched by concurrent increases in precipitation. Our simulation

  1. Enforcing fire safety in the catering industry : an economic analysis.

    NARCIS (Netherlands)

    Suurmond, Guido

    2008-01-01

    What is an effective and efficient enforcement policy for fire safety in the catering industry? When and why is an informal, cooperative enforcement style through warnings, persuasion and advice (a so called compliance strategy) effective in inducing compliance with the fire safety regulation? The

  2. Southwest Oregon Biscuit Fire: an analysis of forest resources and fire severity

    Science.gov (United States)

    David L. Azuma; Joseph Donnegan; Donald. Gedney

    2004-01-01

    The Biscuit Fire in southwestern Oregon was one of the largest and most costly in recent history, burning over 499,000 acres and costing over 150 million dollars in suppression efforts. This study uses prefire resource information in conjunction with postfire burn severity to generate statistically reliable prefire resource estimates for the land within the Biscuit...

  3. Meteosat SEVIRI Fire Radiative Power (FRP) products from the Land Surface Analysis Satellite Applications Facility (LSA SAF) - Part 1: Algorithms, product contents and analysis

    Science.gov (United States)

    Wooster, M. J.; Roberts, G.; Freeborn, P. H.; Xu, W.; Govaerts, Y.; Beeby, R.; He, J.; Lattanzio, A.; Mullen, R.

    2015-06-01

    together with the per-pixel uncertainty metrics. Using scene simulations and analysis of real SEVIRI data, including from a period of Meteosat-8 "special operations", we describe some of the sensor and data pre-processing characteristics influencing fire detection and FRP uncertainty. We show that the FTA algorithm is able to discriminate actively burning fires covering down to 10-4 of a pixel, and is more sensitive to fire than algorithms used within many other widely exploited active fire products. We also find that artefacts arising from the digital filtering and geometric resampling strategies used to generate level 1.5 SEVIRI data can significantly increase FRP uncertainties in the SEVIRI active fire products, and recommend that the processing chains used for the forthcoming Meteosat Third Generation attempt to minimise the impact of these types of operations. Finally, we illustrate the information contained within the current Meteosat FRP-PIXEL and FRP-GRID products, providing example analyses for both individual fires and multi-year regional-scale fire activity. A companion paper (Roberts et al., 2015) provides a full product performance evaluation for both products, along with examples of their use for prescribing fire smoke emissions within atmospheric modelling components of the Copernicus Atmosphere Monitoring Service (CAMS).

  4. Assessment of fire emission inventories during the South American Biomass Burning Analysis (SAMBBA experiment

    Directory of Open Access Journals (Sweden)

    G. Pereira

    2016-06-01

    Full Text Available Fires associated with land use and land cover changes release large amounts of aerosols and trace gases into the atmosphere. Although several inventories of biomass burning emissions cover Brazil, there are still considerable uncertainties and differences among them. While most fire emission inventories utilize the parameters of burned area, vegetation fuel load, emission factors, and other parameters to estimate the biomass burned and its associated emissions, several more recent inventories apply an alternative method based on fire radiative power (FRP observations to estimate the amount of biomass burned and the corresponding emissions of trace gases and aerosols. The Brazilian Biomass Burning Emission Model (3BEM and the Fire Inventory from NCAR (FINN are examples of the first, while the Brazilian Biomass Burning Emission Model with FRP assimilation (3BEM_FRP and the Global Fire Assimilation System (GFAS are examples of the latter. These four biomass burning emission inventories were used during the South American Biomass Burning Analysis (SAMBBA field campaign. This paper analyzes and inter-compared them, focusing on eight regions in Brazil and the time period of 1 September–31 October 2012. Aerosol optical thickness (AOT550 nm derived from measurements made by the Moderate Resolution Imaging Spectroradiometer (MODIS operating on board the Terra and Aqua satellites is also applied to assess the inventories' consistency. The daily area-averaged pyrogenic carbon monoxide (CO emission estimates exhibit significant linear correlations (r, p  >  0.05 level, Student t test between 3BEM and FINN and between 3BEM_ FRP and GFAS, with values of 0.86 and 0.85, respectively. These results indicate that emission estimates in this region derived via similar methods tend to agree with one other. However, they differ more from the estimates derived via the alternative approach. The evaluation of MODIS AOT550 nm indicates that model

  5. CAFE: A Computer Tool for Accurate Simulation of the Regulatory Pool Fire Environment for Type B Packages

    International Nuclear Information System (INIS)

    Gritzo, L.A.; Koski, J.A.; Suo-Anttila, A.J.

    1999-01-01

    The Container Analysis Fire Environment computer code (CAFE) is intended to provide Type B package designers with an enhanced engulfing fire boundary condition when combined with the PATRAN/P-Thermal commercial code. Historically an engulfing fire boundary condition has been modeled as σT 4 where σ is the Stefan-Boltzman constant, and T is the fire temperature. The CAFE code includes the necessary chemistry, thermal radiation, and fluid mechanics to model an engulfing fire. Effects included are the local cooling of gases that form a protective boundary layer that reduces the incoming radiant heat flux to values lower than expected from a simple σT 4 model. In addition, the effect of object shape on mixing that may increase the local fire temperature is included. Both high and low temperature regions that depend upon the local availability of oxygen are also calculated. Thus the competing effects that can both increase and decrease the local values of radiant heat flux are included in a reamer that is not predictable a-priori. The CAFE package consists of a group of computer subroutines that can be linked to workstation-based thermal analysis codes in order to predict package performance during regulatory and other accident fire scenarios

  6. Object-based Forest Fire Analysis for Pedrógão Grande Fire Using Landsat 8 OLI and Sentinel-2A Imagery

    Science.gov (United States)

    Tonbul, H.; Kavzoglu, T.

    2017-12-01

    Forest fires are among the most important natural disasters with the damage to the natural habitat and human-life. Mapping damaged forest fires is crucial for assessing ecological effects caused by fire, monitoring land cover changes and modeling atmospheric and climatic effects of fire. In this context, satellite data provides a great advantage to users by providing a rapid process of detecting burning areas and determining the severity of fire damage. Especially, Mediterranean ecosystems countries sets the suitable conditions for the forest fires. In this study, the determination of burnt areas of forest fire in Pedrógão Grande region of Portugal occurred in June 2017 was carried out using Landsat 8 OLI and Sentinel-2A satellite images. The Pedrógão Grande fire was one of the largest fires in Portugal, more than 60 people was killed and thousands of hectares were ravaged. In this study, four pairs of pre-fire and post-fire top of atmosphere (TOA) and atmospherically corrected images were utilized. The red and near infrared (NIR) spectral bands of pre-fire and post-fire images were stacked and multiresolution segmentation algorithm was applied. In the segmentation processes, the image objects were generated with estimated optimum homogeneity criteria. Using eCognition software, rule sets have been created to distinguish unburned areas from burned areas. In constructing the rule sets, NDVI threshold values were determined pre- and post-fire and areas where vegetation loss was detected using the NDVI difference image. The results showed that both satellite images yielded successful results for burned area discrimination with a very high degree of consistency in terms of spatial overlap and total burned area (over 93%). Object based image analysis (OBIA) was found highly effective in delineation of burnt areas.

  7. Computational fluid dynamic simulations of coal-fired utility boilers: An engineering tool

    Energy Technology Data Exchange (ETDEWEB)

    Efim Korytnyi; Roman Saveliev; Miron Perelman; Boris Chudnovsky; Ezra Bar-Ziv [Ben-Gurion University of the Negev, Beer-Sheva (Israel)

    2009-01-15

    The objective of this study was to develop an engineering tool by which the combustion behavior of coals in coal-fired utility boilers can be predicted. We presented in this paper that computational fluid dynamic (CFD) codes can successfully predict performance of - and emission from - full-scale pulverized-coal utility boilers of various types, provided that the model parameters required for the simulation are properly chosen and validated. For that purpose we developed a methodology combining measurements in a 50 kW pilot-scale test facility with CFD simulations using the same CFD code configured for both test and full-scale furnaces. In this method model parameters of the coal processes are extracted and validated. This paper presents the importance of the validation of the model parameters which are used in CFD codes. Our results show very good fit of CFD simulations with various parameters measured in a test furnace and several types of utility boilers. The results of this study demonstrate the viability of the present methodology as an effective tool for optimization coal burning in full-scale utility boilers. 41 refs., 9 figs., 3 tabs.

  8. Correlation analysis of heat flux and fire behaviour and hazards of polycrystalline silicon photovoltaic panels

    Science.gov (United States)

    Ju, Xiaoyu; Zhou, Xiaodong; Peng, Fei; Wu, Zhibo; Lai, Dimeng; Hu, Yue; Yang, Lizhong

    2017-05-01

    This work aims to gain a better understanding of fire behaviour and hazards of PV panels under different radiation heat fluxes. The cone calorimeter tests were applied to simulate the situations when the front and back surfaces are exposed to heat flux in a fire, respectively. Through comparison of ignition time, mass loss rate and heat release rate, it is found that the back-up condition is more hazardous than face-up condition. Meanwhile, three key parameters: flashover propensity, total heat release and FED, were introduced to quantitatively illustrate fire hazards of a PV panel.

  9. Hydrocarbon characterization experiments in fully turbulent fires : results and data analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Suo-Anttila, Jill Marie; Blanchat, Thomas K.

    2011-03-01

    As the capabilities of numerical simulations increase, decision makers are increasingly relying upon simulations rather than experiments to assess risks across a wide variety of accident scenarios including fires. There are still, however, many aspects of fires that are either not well understood or are difficult to treat from first principles due to the computational expense. For a simulation to be truly predictive and to provide decision makers with information which can be reliably used for risk assessment the remaining physical processes must be studied and suitable models developed for the effects of the physics. The model for the fuel evaporation rate in a liquid fuel pool fire is significant because in well-ventilated fires the evaporation rate largely controls the total heat release rate from the fire. This report describes a set of fuel regression rates experiments to provide data for the development and validation of models. The experiments were performed with fires in the fully turbulent scale range (> 1 m diameter) and with a number of hydrocarbon fuels ranging from lightly sooting to heavily sooting. The importance of spectral absorption in the liquid fuels and the vapor dome above the pool was investigated and the total heat flux to the pool surface was measured. The importance of convection within the liquid fuel was assessed by restricting large scale liquid motion in some tests. These data sets provide a sound, experimentally proven basis for assessing how much of the liquid fuel needs to be modeled to enable a predictive simulation of a fuel fire given the couplings between evaporation of fuel from the pool and the heat release from the fire which drives the evaporation.

  10. Investigation of Lab Fire Prevention Management System of Combining Root Cause Analysis and Analytic Hierarchy Process with Event Tree Analysis

    Directory of Open Access Journals (Sweden)

    Cheng-Chan Shih

    2016-01-01

    Full Text Available This paper proposed a new approach, combining root cause analysis (RCA, analytic hierarchy process (AHP, and event tree analysis (ETA in a loop to systematically evaluate various laboratory safety prevention strategies. First, 139 fire accidents were reviewed to identify the root causes and draw out prevention strategies. Most fires were caused due to runaway reactions, operation error and equipment failure, and flammable material release. These mostly occurred in working places of no prompt fire protection. We also used AHP to evaluate the priority of these strategies and found that chemical fire prevention strategy is the most important control element, and strengthening maintenance and safety inspection intensity is the most important action. Also together with our surveys results, we proposed that equipment design is also critical for fire prevention. Therefore a technical improvement was propounded: installing fire detector, automatic sprinkler, and manual extinguisher in the lab hood as proactive fire protections. ETA was then used as a tool to evaluate laboratory fire risks. The results indicated that the total risk of a fire occurring decreases from 0.0351 to 0.0042 without/with equipment taking actions. Establishing such system can make Environment, Health and Safety (EH&S office not only analyze and prioritize fire prevention policies more practically, but also demonstrate how effective protective equipment improvement can achieve and the probabilities of the initiating event developing into a serious accident or controlled by the existing safety system.

  11. Advanced Simulation Tool for Improved Damage Assessment 2) Water-Mist Suppression of Large Scale Compartment Fires

    National Research Council Canada - National Science Library

    Prasad, Kuldeep

    2000-01-01

    .... In this report, we focus on simulating water-mist suppression of fires in large enclosures. A two-continuum formulation is used in which the gas phase and the water-mist are both described by equations of the Eulerian form...

  12. Gis-Based Multi-Criteria Decision Analysis for Forest Fire Risk Mapping

    Science.gov (United States)

    Akay, A. E.; Erdoğan, A.

    2017-11-01

    The forested areas along the coastal zone of the Mediterranean region in Turkey are classified as first-degree fire sensitive areas. Forest fires are major environmental disaster that affects the sustainability of forest ecosystems. Besides, forest fires result in important economic losses and even threaten human lives. Thus, it is critical to determine the forested areas with fire risks and thereby minimize the damages on forest resources by taking necessary precaution measures in these areas. The risk of forest fire can be assessed based on various factors such as forest vegetation structures (tree species, crown closure, tree stage), topographic features (slope and aspect), and climatic parameters (temperature, wind). In this study, GIS-based Multi-Criteria Decision Analysis (MCDA) method was used to generate forest fire risk map. The study was implemented in the forested areas within Yayla Forest Enterprise Chiefs at Dursunbey Forest Enterprise Directorate which is classified as first degree fire sensitive area. In the solution process, "extAhp 2.0" plug-in running Analytic Hierarchy Process (AHP) method in ArcGIS 10.4.1 was used to categorize study area under five fire risk classes: extreme risk, high risk, moderate risk, and low risk. The results indicated that 23.81 % of the area was of extreme risk, while 25.81 % was of high risk. The result indicated that the most effective criterion was tree species, followed by tree stages. The aspect had the least effective criterion on forest fire risk. It was revealed that GIS techniques integrated with MCDA methods are effective tools to quickly estimate forest fire risk at low cost. The integration of these factors into GIS can be very useful to determine forested areas with high fire risk and also to plan forestry management after fire.

  13. GIS-BASED MULTI-CRITERIA DECISION ANALYSIS FOR FOREST FIRE RISK MAPPING

    Directory of Open Access Journals (Sweden)

    A. E. Akay

    2017-11-01

    Full Text Available The forested areas along the coastal zone of the Mediterranean region in Turkey are classified as first-degree fire sensitive areas. Forest fires are major environmental disaster that affects the sustainability of forest ecosystems. Besides, forest fires result in important economic losses and even threaten human lives. Thus, it is critical to determine the forested areas with fire risks and thereby minimize the damages on forest resources by taking necessary precaution measures in these areas. The risk of forest fire can be assessed based on various factors such as forest vegetation structures (tree species, crown closure, tree stage, topographic features (slope and aspect, and climatic parameters (temperature, wind. In this study, GIS-based Multi-Criteria Decision Analysis (MCDA method was used to generate forest fire risk map. The study was implemented in the forested areas within Yayla Forest Enterprise Chiefs at Dursunbey Forest Enterprise Directorate which is classified as first degree fire sensitive area. In the solution process, "extAhp 2.0" plug-in running Analytic Hierarchy Process (AHP method in ArcGIS 10.4.1 was used to categorize study area under five fire risk classes: extreme risk, high risk, moderate risk, and low risk. The results indicated that 23.81 % of the area was of extreme risk, while 25.81 % was of high risk. The result indicated that the most effective criterion was tree species, followed by tree stages. The aspect had the least effective criterion on forest fire risk. It was revealed that GIS techniques integrated with MCDA methods are effective tools to quickly estimate forest fire risk at low cost. The integration of these factors into GIS can be very useful to determine forested areas with high fire risk and also to plan forestry management after fire.

  14. Qualitative Analysis Results for Applications of a New Fire Probabilistic Safety Assessment Method to Ulchin Unit 3

    International Nuclear Information System (INIS)

    Kang, Daeil; Kim, Kilyoo; Jang, Seungcheol

    2013-01-01

    The fire PRA Implementation Guide has been used for performing a fire PSA for NPPs in Korea. Recently, US NRC and EPRI developed a new fire PSA method, NUREG/CR-6850, to provide state-of-the-art methods, tools, and data for the conduct of a fire PSA for a commercial nuclear power plant (NPP). Due to the limited budget and man powers for the development of KSRP, hybrid PSA approaches, using NUREG/CR-6850 and Fire PRA Implementation Guide, will be employed for conducting a fire PSA of Ulchin Unit 3. In this paper, the qualitative analysis results for applications of a new fire PSA method to Ulchin Unit 3 are presented. This paper introduces the qualitative analysis results for applications of a new fire PSA method to Ulchin Unit 3. Compared with the previous industry, the number of fire areas for quantification identified and the number of equipment selected has increased

  15. An enhanced real-time forest fire assessment algorithm based on video by using texture analysis

    Directory of Open Access Journals (Sweden)

    Gudikandhula Narasimha Rao

    2016-09-01

    Full Text Available As the human technology moved further, the risk of natural and man induced sudden damage increase exponentially. One of the most dangerous disasters is fire. In addition to its direct danger on human's lives, fire consumes forests where trees that provide humans with oxygen are destroyed. Every year, the large number of wildfires happening all over the world they burn forested lands, causing adverse ecological and social impacts. Early warning and immediate responses are the only ways to avoid such type of disasters. This work describes a naïve method is used to detect flames in forest by using a Spatio Wildfire Prediction and Monitoring System (SWPMS. Basically, the fired information retrieving from regions by using background subtraction and colour analysis. The fire behaviour is modelled by texture analysis using computer vision systems. The Central Server should receives fired regions from the volunteer's smart phone and use fired location coordinates, different angles of smart phone receives fired locations based on Google Earth API. Finally, Kalman filter estimator computes the position vector of a moving object. Antennas or Satellite systems are grasping information from fire regions then GIS will be analyzed those regions and send alert to local peoples of forest regions and NDRF team.

  16. Stochastic representation of fire behavior in a wildland fire protection planning model for California.

    Science.gov (United States)

    J. Keith Gilless; Jeremy S. Fried

    1998-01-01

    A fire behavior module was developed for the California Fire Economics Simulator version 2 (CFES2), a stochastic simulation model of initial attack on wildland fire used by the California Department of Forestry and Fire Protection. Fire rate of spread (ROS) and fire dispatch level (FDL) for simulated fires "occurring" on the same day are determined by making...

  17. PCDD/F and aromatic emissions from simulated forest and grassland fires

    Science.gov (United States)

    Gullett, B.; Touati, A.; Oudejans, L.

    Emissions of polychlorinated dibenzodioxin and polychlorinated dibenzofuran (PCDD/F) from simulated grassland and forest fires were quantitatively sampled to derive emission factors in support of PCDD/F inventory development. Grasses from Kentucky and Minnesota; forest shrubs from California and Florida; and pine forest biomass from the Piedmont region of North Carolina, western North Carolina, and coastal Oregon were collected and tested in a burn facility that mimicked a prescribed fire in the natural environment scenario. Ambient sampling methods for PCDD/F were variously accompanied by real-time measurements of major aromatic species, including benzene, toluene, naphthalene, and styrene. Emission factors in mass of toxic equivalent (TEQ) of PCDD/F per kg of carbon burned (kg Cb) for the two grasses averaged 0.32 ng TEQ/kg Cb. Burn tests ( n = 27) on forest biomass from the five sources show PCDD/F emission factors ranging from 0.3 to 26.3 ng TEQ/kg Cb, with a mean and median of 5.8 and 3.3 ng TEQ/kg Cb, respectively. Variation of the forest green/brown needle content, sample size, burn scenario, and facility ventilation rate showed no consistent effects on PCDD/F emissions. For forest burns, 30-35% of the PCDD and 50-55% of the PCDF emissions occurred during the flaming period from 0 to 5 min, while the highest emission factors (per mass of carbon burned) were recorded during the smoldering period from 5 to 60 min. Emissions of PCDD/F exceeded those present in the raw biomass by a factor of four, confirming PCDD/F formation from combustion rather than from simple surface volatilization. The majority of the PCDD/F partitions to the emissions rather than the ash.

  18. Fire activity inside and outside protected areas in Sub-Saharan Africa: a continental analysis of fire and its implications for biodiversity and land management

    Science.gov (United States)

    Palumbo, Ilaria; Gregoire, Jean-Marie; Simonetti, Dario; Punga, Mihkel; Dubois, Gregoire

    2010-05-01

    around each of them. The region outside the protected areas was used for comparison in order to identify differences or similarities between their fire activities. This also contributed to understand how management and conservation influence fire and assess the level of isolation of the protected areas. The long time series allowed the identification of trends and the interannual variability of the fire activity. The dry season length was determined using FEWS RFE rainfall data (implemented at NOAA's Climate Prediction Center). Within each dry season we identified three periods (early, middle and late) in order to characterize the climatic and environmental conditions at which fires occur and identify trends and patterns. Every period of the dry season lasts two months and shows different conditions of temperature and drought level. Fire activity was characterized combining the information on active fires and burned areas. For each year we determined the fire seasonality, the fire frequency, the main vegetation types affected, the extent and intensity of burning. This information was also used to distinguish management fires from those related to other human activities like transhumance, agriculture and poaching in order to identify possible sources of threat to the protected areas. Information on the road network, the location of villages and cultivated fields were also included. Future work will include a combined analysis of fire activity and land-cover, land-cover change information so that management plans adopted in protected areas can be evaluated in their effectiveness to promote biodiversity and nature conservation.

  19. Fire activity inside and outside protected areas in Sub-Saharan Africa: a continental analysis of fire and its implications for biodiversity and management

    Science.gov (United States)

    Palumbo, Ilaria; Gregoire, Jean-Marie; Simonetti, Dario; Punga, Mihkel; Dubois, Gregoire

    2010-05-01

    around each of them. The region outside the protected areas was used for comparison in order to identify differences or similarities between their fire activities. This also contributed to understand how management and conservation influence fire and assess the level of isolation of the protected areas. The long time series allowed the identification of trends and the interannual variability in the fire activity. The dry season length was determined using FEWS RFE rainfall data (implemented at NOAA's Climate Prediction Center). Within each dry season we identified three periods (early, middle and late) in order to characterize the climatic and environmental conditions at which fires occur and identify trends and patterns. Every period of the dry season lasts two months and shows different conditions of temperature and drought level. Fire activity was characterized combining the information on active fires and burned areas. For each year we determined the fire seasonality, the fire frequency, the main vegetation types affected, the extent and intensity of burning. This information was also used to distinguish management fires from those related to other human activities like transhumance, agriculture and poaching in order to identify possible sources of threat to the protected areas. Information on the road network, the location of villages and cultivated fields were also included. Future work will include a combined analysis of fire activity and land-cover, land-cover change information so that management plans adopted in protected areas can be evaluated in their effectiveness to promote biodiversity and nature conservation.

  20. Root-cause analysis of burner tip failures in coal-fired power plants

    International Nuclear Information System (INIS)

    Citirik, E.

    2014-01-01

    Warpage and complete or partial tear of burner material was frequently experienced in coal-fired power plants due to material overheating. Root-cause analysis of a burner tip failure is investigated employing stress modeling in the burner tip material in this study. The analyses performed in this research paper include heat transfer and stress analyses employing computational tools. Thermal analysis was performed using Computational Fluid Dynamics (CFD) software FLUENT for computing temperature distribution within the burner tip due to convection and radiation. Once the temperature distribution in the burner tip is determined, Finite Element Analysis (FEA) is employed using ANSYS to determine the maximum stress and deformations in burner tip material. Both FLUENT and ANSYS are numerical commercial simulation tools employed in this study. Large temperature gradients along the burner tip result in local bending stresses. These stresses resulting in creep stresses might be causing warpage in the burner tip. In this study, a design option was exercised to eliminate the excessive stress gradient in the burner tip material. Seven different FEA models were developed to simulate different operating conditions. Proposed design modification (Model 5) was able to reduce the maximum compressive stress from 76.09 MPa to 33.59 MPa. Significant reduction in the thermal stress due to design modification in Model 5 made author believe that the proposed design solution would eliminate the burner tip failures in this particular power plant. - Highlights: • Maximum stress and displacement values in the baseline model were computed. • Computations were performed using commercial FEA software ANSYS. • Different operating conditions were simulated in models 1-2-3-4. • Proposed geometry to prevent the failure is simulated in Models 5 and 6. • The proposed design solution reduced the maximum compressive stresses by ∼50%

  1. Crown Fire Potential

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Crown fire potential was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The...

  2. Heat transfer analysis of special reinforced NSC-columns under severe fire conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sismanis, Panagiotis G. [SIDENOR SA, Main Technical Office, Athens (Greece)

    2010-03-15

    The 3-D heat conduction equation was numerically solved and the temperature distribution inside two special metallic frames, loaded with the proper number of reinforced bars, encased by normal strength concrete in the final columnar form, and subject to intense fire conditions, was computed by time. Typical temperature profiles were applied for the simulation of the cellulosic and hydrocarbon kinds of fire. Heat transfer by radiation and convection was included in the surrounding the column medium under fire, testing various convective heat-transfer coefficients. Computational results were analyzed until the critical time period in which the integrity and the mechanical strength of the column were reversible, considering fire abatement until that time. (orig.)

  3. Enhancements in PSA regulation and guidance on fire risk analysis for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Heinz-Peter [Bundesamt fuer Strahlenschutz (BfS), Salzgitter (Germany)

    2015-12-15

    Fire PSA (probabilistic safety analysis) is required as part of the probabilistic safety assessment within Periodic Safety Reviews (PSR) in Germany. Fire PSAs have been conducted for all nuclear power plants in Germany within the second PSR. Thus, Fire PSA has become an additional tool to supplement deterministic assessment of the fire protection for supporting decision making, but has been focused on full power plant operational states. However, according to the German PSA Guideline and its corresponding technical documents on PSA methods and data issued 2005, the scope was extended to low power and shutdown states, however not assessing internal and external hazards for these states. The most recent activities with regard to PSA as supplementary tool for safety assessment focus on improvements with respect to low power and shutdown (LPSD), considering fuel damage states, and in addition covering internal hazards, in particular fire. For each phase during LPSD those compartments or plant areas have to be identified where fire events may inadmissibly impair items important to safety. The extension of Fire PSA to LPSD states has to be particularly applied to those plants, for which a third PSR is required by the German regulation. In addition, the safety significance of those plant modifications important to safety should be evaluated, for which a significant effect on the PSA results can be expected. This also covers the safety demonstration that the fire safety means needed to meet the nuclear protection goals are adequate.

  4. Estimation of the firing distance through micro-CT analysis of gunshot wounds.

    Science.gov (United States)

    Cecchetto, Giovanni; Giraudo, Chiara; Amagliani, Alessandro; Viel, Guido; Fais, Paolo; Cavarzeran, Fabiano; Feltrin, Giampietro; Ferrara, Santo Davide; Montisci, Massimo

    2011-03-01

    Estimation of the firing range is often critical for reconstructing gunshot fatalities, where the main measurable evidence is the gunshot residue (GSR). In the present study intermediate-range gunshot wounds have been analysed by means of a micro-computed tomography (micro-CT) coupled to an image analysis software in order to quantify the powder particles and to determine the firing distance. A total of 50 shootings were performed on skin sections obtained from human legs surgically amputated for medical reasons. For each tested distance (5, 15, 23, 30 and 40 cm), firing was carried out perpendicularly at the samples using a 7.65-mm pistol loaded with jacketed bullets. Uninjured skin sections were used as controls. By increasing the firing distance, micro-CT analysis demonstrated a clear decreasing trend in the mean GSR percentage, particularly for shots fired from more than 15 cm. For distances under 23 cm, the powder particles were concentrated on the epidermis and dermis around the hole, and inside the cavity; while, at greater distances, they were deposited only on the skin surface. Statistical analysis showed a nonlinear relationship between the amount of GSR deposits and the firing range, well explained by a Gaussian-like function. The proposed method allowed a good discrimination for all the tested distances, proving to be an objective, rapid and inexpensive tool for estimating the firing range in intermediate-range gunshot wounds.

  5. Mechanistic approach to the sodium leakage and fire analysis

    International Nuclear Information System (INIS)

    Yamaguchi, Akira; Muramatsu, Toshiharu; Ohira, Hiroaki; Ida, Masao

    1997-04-01

    In December 1995, a thermocouple well was broken and liquid sodium leaked out of the intermediate heat transport system of the prototype fast breeder reactor Monju. In the initiating process of the incident, liquid sodium flowed out through the hollow thermocouple well, nipple and connector. As a result, liquid sodium, following ignition and combustion, was dropping from the connector to colide with the duct and grating placed below. The collision may cause fragmentation and scattering of the sodium droplet that finally was piled up on the floor. This report deals with the development of computer programs for the phenomena based on mechanistics approach. Numerical analyses are also made for fundamental sodium leakage and combustion phenomenon, sodium combustion experiment, and Monju incident condition. The contents of this report is listed below: (1) Analysis of chemical reaction process based on molecular orbital method, (2) Thermalhy draulic analysis of the sodium combustion experiment II performed in 1996 at O-arai Engineering Center, PNC, (3) Thermalhy draulic analysis of room A-446 of Monju reactor when the sodium leakage took place, (4) Direct numerical simulation of sodium droplet, (5) Sodium leakage and scattering analysis using three dimensional particle method, (6) Multi-dimensional combustion analysis and multi-point approximation combustion analysis code. Subsequent to the development work of the programs, they are to be applied to the safety analysis of the Fast Breeder Reactor. (author)

  6. Intercomparison of cloud model simulations of Arctic mixed-phase boundary layer clouds observed during SHEBA/FIRE-ACE

    Directory of Open Access Journals (Sweden)

    Mikhail Ovchinnikov

    2011-06-01

    Full Text Available An intercomparison of six cloud-resolving and large-eddy simulation models is presented. This case study is based on observations of a persistent mixed-phase boundary layer cloud gathered on 7 May, 1998 from the Surface Heat Budget of Arctic Ocean (SHEBA and First ISCCP Regional Experiment - Arctic Cloud Experiment (FIRE-ACE. Ice nucleation is constrained in the simulations in a way that holds the ice crystal concentration approximately fixed, with two sets of sensitivity runs in addition to the baseline simulations utilizing different specified ice nucleus (IN concentrations. All of the baseline and sensitivity simulations group into two distinct quasi-steady states associated with either persistent mixed-phase clouds or all-ice clouds after the first few hours of integration, implying the existence of multiple equilibria. These two states are associated with distinctly different microphysical, thermodynamic, and radiative characteristics. Most but not all of the models produce a persistent mixed-phase cloud qualitatively similar to observations using the baseline IN/crystal concentration, while small increases in the IN/crystal concentration generally lead to rapid glaciation and conversion to the all-ice state. Budget analysis indicates that larger ice deposition rates associated with increased IN/crystal concentrations have a limited direct impact on dissipation of liquid in these simulations. However, the impact of increased ice deposition is greatly enhanced by several interaction pathways that lead to an increased surface precipitation flux, weaker cloud top radiative cooling and cloud dynamics, and reduced vertical mixing, promoting rapid glaciation of the mixed-phase cloud for deposition rates in the cloud layer greater than about 1-2x10-5 g kg-1 s-1. These results indicate the critical importance of precipitation-radiative-dynamical interactions in simulating cloud phase, which have been neglected in previous fixed-dynamical parcel

  7. Development of the dynamic plant simulation in CO{sub 2}-recovery type pulverized-coal fired power plant applied oxygen/recycled flue gas combustion

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, T.; Kiga, T.; Fujita, N.; Inoue, T.; Murata, Y.; Arai, K.; Okawa, M.; Seo, Y.

    1999-07-01

    Based on the basic designing of 1,000 MW power plant, the dynamic plant simulation was conducted in order to confirm the realization of the oxygen/recycled flue gas (O{sub 2}/RFG) combustion system to recover CO{sub 2} from pulverized-coal fired power plants. First of all, the basic designing of 1,000 MWe pulverized-coal fired power plant applied O{sub 2}/RFG combustion was performed. In the system, the greater part of the flue gas from the boiler was recycled and used as combustion gas after mixing with oxygen and transported gas for pulverized-coal. Five air separation units (ASUs) were installed and they supplied the product oxygen controlled in oxygen flow rate and oxygen concentration to the boiler. During load change, start up and shut down of the plant, therefore it was supposed to be difficult to control the flue gas oxygen concentration, the wind box oxygen concentration, the steam condition and so on in the system. So as to make clear the operation ability of the plant, the dynamic simulation was conducted based on the results of the basic designing on engineering work stations (EWS) for plant load change and start up. The program of the dynamic characteristics analysis simulator was developed as a functional expansion of advanced power plant simulation system (APSS) which had been developed by IHI for energy power plants. As the results, it was found that the steam condition at the outlet of the boiler and the draft and the gas concentration at each point could be successfully controlled, though it took a long time to change the combustion mode from air combustion to O{sub 2}/RFG combustion. Finally, it was confirmed that pulverized-coal fired power plant applied O{sub 2}/RFG combustion was a practical system for CO{sub 2} recovery.

  8. Fire investigation and ignitable liquid residue analysis--a review: 2001-2007.

    Science.gov (United States)

    Sandercock, P Mark L

    2008-04-07

    Next to natural disasters fires cause some of the greatest losses to property and human life around the world. Arson, the deliberate setting of a fire to destroy property or to take a human life, is one of the most difficult crimes to investigate because much of the evidence at the scene is destroyed by the fire. Fortunately, the science of fire investigation is not static and more information to help investigators determine the origin and cause of a fire through careful examination of the scene and laboratory analysis of fire debris is published every year. This review article provides an overview of the scientific literature describing research and best practices in the fields of fire scene investigation as well as ignitable liquid residue analysis. This review is a compilation of articles published between late 2001 and early 2007. Conference proceedings for which full papers have not been published were intentionally excluded from this review. Some of the information contained in this review was presented at the 14th Interpol Forensic Science Symposium held in Lyon, France in October 2004.

  9. Long-range correlations in the fire sequences with Detrended Fluctuation Analysis

    Science.gov (United States)

    Zheng, H.; Song, W.

    2009-04-01

    Forest fires have been found to exhibit good power-law relation in the frequency-size distribution over many orders of magnitude in different countries, which identifies that forest fires behave as self-organized criticality (SOC). And in the temporal aspect, it is also found that the frequency-interval distributions of fires obey power-law with periodic fluctuations. The fire sequences cannot generally be described as Poisson point process, because the distribution of the occurrence times is not homogeneous and shows a clustering behavior. So the power-law distributions, the scaling behavior of the parameters are usually used to describe the sequence. Inter-event time series, the waiting-time between consecutive events, were studied in the similar earthquakes system in recent years, focusing on the distributions and the intrinsic mechanism. In order to find the long-range correlations of fire sequences, we analyzed the scaling behavior of the fires occurred in some places of Asia by means of the detrended fluctuation analysis (DFA), which provides the information of the scaling behavior and long-range characteristics in non-stationary time series. The scaling exponents, larger than 0.5, indicate the presence of persistent long-range correlations, while it performs white noise at 0.5. The detail fire data were investigated in several places, and with the different thresholds of the burned areas or losses. The result reveals the existence of long-range correlations in the fire interval sequences, and the scaling exponents are quite constant over several orders of magnitude. But the exponents are different from each other, possibly due to the orientation of the places we analyzed and other local influencing factors: human activity, weather, economic etc. Besides, the fire sequences of different types were studied in the same way, to find out the possible different long-range behaviors and their possible reasons. The results seem to be helpful to understand the

  10. A meta-analysis of the fire-oak hypothesis: Does prescribed burning promote oak reproduction in eastern North America

    Science.gov (United States)

    Patrick H. Brose; Daniel C. Dey; Ross J. Phillips; Thomas A. Waldrop

    2013-01-01

    The fire-oak hypothesis asserts that the current lack of fire is a reason behind the widespread oak (Quercus spp.) regeneration difficulties of eastern North America, and use of prescribed burning can help solve this problem. We performed a meta-analysis on the data from 32 prescribed fire studies conducted in mixed-oak forests to test whether they...

  11. Impacts of global open-fire aerosols on direct radiative, cloud and surface-albedo effects simulated with CAM5

    Directory of Open Access Journals (Sweden)

    Y. Jiang

    2016-11-01

    Full Text Available Aerosols from open-land fires could significantly perturb the global radiation balance and induce climate change. In this study, Community Atmosphere Model version 5 (CAM5 with prescribed daily fire aerosol emissions is used to investigate the spatial and seasonal characteristics of radiative effects (REs, relative to the case of no fires of open-fire aerosols including black carbon (BC and particulate organic matter (POM from 2003 to 2011. The global annual mean RE from aerosol–radiation interactions (REari of all fire aerosols is 0.16 ± 0.01 W m−2 (1σ uncertainty, mainly due to the absorption of fire BC (0.25 ± 0.01 W m−2, while fire POM induces a small effect (−0.05 and 0.04 ± 0.01 W m−2 based on two different methods. Strong positive REari is found in the Arctic and in the oceanic regions west of southern Africa and South America as a result of amplified absorption of fire BC above low-level clouds, in general agreement with satellite observations. The global annual mean RE due to aerosol–cloud interactions (REaci of all fire aerosols is −0.70 ± 0.05 W m−2, resulting mainly from the fire POM effect (−0.59 ± 0.03 W m−2. REari (0.43 ± 0.03 W m−2 and REaci (−1.38 ± 0.23 W m−2 in the Arctic are stronger than in the tropics (0.17 ± 0.02 and −0.82 ± 0.09 W m−2 for REari and REaci, although the fire aerosol burden is higher in the tropics. The large cloud liquid water path over land areas and low solar zenith angle of the Arctic favor the strong fire aerosol REaci (up to −15 W m−2 during the Arctic summer. Significant surface cooling, precipitation reduction and increasing amounts of low-level cloud are also found in the Arctic summer as a result of the fire aerosol REaci based on the atmosphere-only simulations. The global annual mean RE due to surface-albedo changes (REsac over land areas (0.03 ± 0.10 W m−2 is small and

  12. Fire Hazard Analysis for the Cold Vacuum Drying facility (CVD) Facility

    International Nuclear Information System (INIS)

    SINGH, G.

    2000-01-01

    The CVDF is a nonreactor nuclear facility that will process the Spent Nuclear Fuels (SNF) presently stored in the 105-KE and 105-KW SNF storage basins. Multi-canister overpacks (MCOs) will be loaded (filled) with K Basin fuel transported to the CVDF. The MCOs will be processed at the CVDF to remove free water from the fuel cells (packages). Following processing at the CVDF, the MCOs will be transported to the CSB for interim storage until a long-term storage solution can be implemented. This operation is expected to start in November 2000. A Fire Hazard Analysis (FHA) is required for all new facilities and all nonreactor nuclear facilities, in accordance with U.S. Department of Energy (DOE) Order 5480.7A, Fire Protection. This FHA has been prepared in accordance with DOE 5480.7A and HNF-PRO-350, Fire Hazard Analysis Requirements. Additionally, requirements or criteria contained in DOE, Richland Operations Office (RL) RL Implementing Directive (RLID) 5480.7, Fire Protection, or other DOE documentation are cited, as applicable. This FHA comprehensively assesses the risk of fire at the CVDF to ascertain whether the specific objectives of DOE 5480.7A are met. These specific fire protection objectives are: (1) Minimize the potential for the occurrence of a fire. (2) Ensure that fire does not cause an onsite or offsite release of radiological and other hazardous material that will threaten the public health and safety or the environment. (3) Establish requirements that will provide an acceptable degree of life safety to DOE and contractor personnel and ensure that there are no undue hazards to the public from fire and its effects in DOE facilities. (4) Ensure that vital DOE programs will not suffer unacceptable delays as a result of fire and related perils. (5) Ensure that property damage from fire and related perils does not exceed an acceptable level. (6) Ensure that process control and safety systems are not damaged by fire or related perils. This FHA is based on the

  13. Fire Hazard Analysis for the Cold Vacuum Drying facility (CVD) Facility

    Energy Technology Data Exchange (ETDEWEB)

    SINGH, G.

    2000-09-06

    The CVDF is a nonreactor nuclear facility that will process the Spent Nuclear Fuels (SNF) presently stored in the 105-KE and 105-KW SNF storage basins. Multi-canister overpacks (MCOs) will be loaded (filled) with K Basin fuel transported to the CVDF. The MCOs will be processed at the CVDF to remove free water from the fuel cells (packages). Following processing at the CVDF, the MCOs will be transported to the CSB for interim storage until a long-term storage solution can be implemented. This operation is expected to start in November 2000. A Fire Hazard Analysis (FHA) is required for all new facilities and all nonreactor nuclear facilities, in accordance with U.S. Department of Energy (DOE) Order 5480.7A, Fire Protection. This FHA has been prepared in accordance with DOE 5480.7A and HNF-PRO-350, Fire Hazard Analysis Requirements. Additionally, requirements or criteria contained in DOE, Richland Operations Office (RL) RL Implementing Directive (RLID) 5480.7, Fire Protection, or other DOE documentation are cited, as applicable. This FHA comprehensively assesses the risk of fire at the CVDF to ascertain whether the specific objectives of DOE 5480.7A are met. These specific fire protection objectives are: (1) Minimize the potential for the occurrence of a fire. (2) Ensure that fire does not cause an onsite or offsite release of radiological and other hazardous material that will threaten the public health and safety or the environment. (3) Establish requirements that will provide an acceptable degree of life safety to DOE and contractor personnel and ensure that there are no undue hazards to the public from fire and its effects in DOE facilities. (4) Ensure that vital DOE programs will not suffer unacceptable delays as a result of fire and related perils. (5) Ensure that property damage from fire and related perils does not exceed an acceptable level. (6) Ensure that process control and safety systems are not damaged by fire or related perils. This FHA is based on the

  14. Physicomathematical Simulation Analysis for Small Bullets

    Directory of Open Access Journals (Sweden)

    D. P. Margaris

    2008-01-01

    Full Text Available A full six degrees of freedom (6-DOF flight dynamics model is proposed for the accurate prediction of short and long-range trajectories of small bullets via atmospheric flight to final impact point. The mathematical model is based on the full equations of motion set up in the no-roll body reference frame and is integrated numerically from given initial conditions at the firing site. The projectile maneuvering motion depends on the most significant force and moment variations, in addition to gravity and Magnus effect. The computational flight analysis takes into consideration the Mach number and total angle of attack effects by means of the variable aerodynamic coefficients. For the purposes of the present work, linear interpolation has been applied for aerodynamic coefficients from the official tabulated database. The developed computational method gives satisfactory agreement with published data of verified experiments and computational codes on atmospheric projectile trajectory analysis for various initial firing flight conditions.

  15. Sequential use of simulation and optimization in analysis and planning

    Science.gov (United States)

    Hans R. Zuuring; Jimmie D. Chew; J. Greg Jones

    2000-01-01

    Management activities are analyzed at landscape scales employing both simulation and optimization. SIMPPLLE, a stochastic simulation modeling system, is initially applied to assess the risks associated with a specific natural process occurring on the current landscape without management treatments, but with fire suppression. These simulation results are input into...

  16. IMPROVEMENT SUPPORT RESEARCH OF LOCAL DISASTER PREVENTION POWER USING THE FIRE SPREADING SIMULATION SYSTEM IN CASE OF A BIG EARTHQUAKE

    Science.gov (United States)

    Futagami, Toru; Omoto, Shohei; Hamamoto, Kenichirou

    This research describes the risk communication towards improvement in the local disaster prevention power for Gobusho town in Marugame city which is only a high density city area in Kagawa Pref. Specifically, the key persons and authors of the area report the practice research towards improvement in the local disaster prevention power by the PDCA cycle of the area, such as formation of local voluntary disaster management organizations and implementation of an emergency drill, applying the fire spreading simulation system in case of a big earthquake. The fire spreading simulation system in case of the big earthquake which authors are developing describes the role and subject which have been achieved to BCP of the local community as a support system.

  17. Analysis on ventilation pressure of fire area in longitudinal ventilation of underground tunnel

    Science.gov (United States)

    Li, Jiaxin; Li, Yanfeng; Feng, Xiao; Li, Junmei

    2018-03-01

    In order to solve the problem of ventilation pressure loss in the fire area under the fire condition, the wind pressure loss model of the fire area is established based on the thermodynamic equilibrium relation. The semi-empirical calculation formula is obtained by using the model experiment and CFD simulation. The validity of the formula is verified. The results show that the ventilation pressure loss in the fire zone is proportional to the convective heat release rate at the critical velocity, which is inversely proportional to the upstream ventilation velocity and the tunnel cross-sectional area. The proposed formula is consistent with the law of the tunnel fire test fitting formula that results are close, in contrast, the advantage lies in a clear theoretical basis and ventilation velocity values. The resistance of road tunnel ventilation system is calculated accurately and reliably, and then an effective emergency ventilation operation program is developed. It is necessary to consider the fire zone ventilation pressure loss. The proposed ventilation pressure loss formula can be used for design calculation after thorough verification.

  18. A synoptic climatology for forest fires in the NE US and future implications for GCM simulations

    Science.gov (United States)

    Yan Qing; Ronald Sabo; Yiqiang Wu; J.Y. Zhu

    1994-01-01

    We studied surface-pressure patterns corresponding to reduced precipitation, high evaporation potential, and enhanced forest-fire danger for West Virginia, which experienced extensive forest-fire damage in November 1987. From five years of daily weather maps we identified eight weather patterns that describe distinctive flow situations throughout the year. Map patterns...

  19. Parallel and oblique proton fire hose instabilities in the presence of alpha/proton drift: Hybrid simulations

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Trávníček, Pavel

    2006-01-01

    Roč. 111, č. A1 (2006), A01107/1-A01107/7 ISSN 0148-0227 R&D Projects: GA AV ČR IAA3042403 Grant - others:ESA(XE) PECS 98024 Institutional research plan: CEZ:AV0Z30420517 Keywords : proton temperature anisotropy * fire hose instability * hybrid simulations Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.800, year: 2006

  20. Fire hazards analysis of the Radioactive Waste Management Complex Air Support Buildings

    International Nuclear Information System (INIS)

    Davis, M.L.; Satterwhite, D.G.

    1989-09-01

    This report describes the methods, analyses, results, and conclusions of a fire hazards risk analysis performed for the RWMC Air Support Buildings. An evaluation of the impact for adding a sprinkler system is also presented. Event and fault trees were used to model and analyze the waste storage process. Tables are presented indicating the fire initiators providing the highest potential for release of radioactive materials into the environment. Engineering insights drawn form the data are also provided

  1. Fire hazards analysis of the Radioactive Waste Management Complex Air Support Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Davis, M.L.; Satterwhite, D.G.

    1989-09-01

    This report describes the methods, analyses, results, and conclusions of a fire hazards risk analysis performed for the RWMC Air Support Buildings. An evaluation of the impact for adding a sprinkler system is also presented. Event and fault trees were used to model and analyze the waste storage process. Tables are presented indicating the fire initiators providing the highest potential for release of radioactive materials into the environment. Engineering insights drawn form the data are also provided.

  2. Dynamic analysis and simulation at Chalk River

    International Nuclear Information System (INIS)

    Green, R.E.

    1976-01-01

    The paper outlines the role of dynamic analysis/simulation within AECL, discusses briefly some recent dynamic analysis/simulation studies in the Reactor Control Branch at CRNL, describes the dynamic simulation facilities being used by the Branch, and discusses the operation of the Dynamic Analysis Centre and how it might be used by analysts from outside the Reactor Control Branch and indeed, outside AECL. (author)

  3. Analysis of fire and smoke threat to off-gas HEPA filters in a transuranium processing plant

    International Nuclear Information System (INIS)

    Alvares, N.J.

    1988-01-01

    The author performed an analysis of fire risk to the high-efficiency particulate air (HEPA) filters that provide ventilation containment for a transuranium processing plant at the Oak Ridge National Laboratory. A fire-safety survey by an independent fire-protection consulting company had identified the HEPA filters in the facility's off-gas containment ventilation system as being at risk from fire effects. Independently studied were the ventilation networks and flow dynamics, and typical fuel loads were analyzed. It was found that virtually no condition for fire initiation exists and that, even if a fire started, its consequences would be minimal as a result of standard shut-down procedures. Moreover, the installed fire-protection system would limit any fire and thus would further reduce smoke or heat exposure to the ventilation components. 4 references, 4 figures, 5 tables

  4. The Simulations of Wildland Fire Smoke PM25 in the NWS Air Quality Forecasting Systems

    Science.gov (United States)

    Huang, H. C.; Pan, L.; McQueen, J.; Lee, P.; ONeill, S. M.; Ruminski, M.; Shafran, P.; Huang, J.; Stajner, I.; Upadhayay, S.; Larkin, N. K.

    2017-12-01

    The increase of wildland fire intensity and frequency in the United States (U.S.) has led to property loss, human fatality, and poor air quality due to elevated particulate matters and surface ozone concentrations. The NOAA/National Weather Service (NWS) built the National Air Quality Forecast Capability (NAQFC) based on the U.S. Environmental Protection Agency (EPA) Community Multi-scale Air Quality (CMAQ) Modeling System driven by the NCEP North American Mesoscale Forecast System meteorology to provide ozone and fine particulate matter (PM2.5) forecast guidance publicly. State and local forecasters use the NWS air quality forecast guidance to issue air quality alerts in their area. The NAQFC PM2.5 predictions include emissions from anthropogenic and biogenic sources, as well as natural sources such as dust storms and wildland fires. The wildland fire emission inputs to the NAQFC is derived from the NOAA National Environmental Satellite, Data, and Information Service Hazard Mapping System fire and smoke detection product and the emission module of the U.S. Forest Service (USFS) BlueSky Smoke Modeling Framework. Wildland fires are unpredictable and can be ignited by natural causes such as lightning or be human-caused. It is extremely difficult to predict future occurrences and behavior of wildland fires, as is the available bio-fuel to be burned for real-time air quality predictions. Assumptions of future day's wildland fire behavior often have to be made from older observed wildland fire information. The comparisons between the NAQFC modeled PM2.5 and the EPA AirNow surface observation show that large errors in PM2.5 prediction can occur if fire smoke emissions are sometimes placed at the wrong location and/or time. A configuration of NAQFC CMAQ-system to re-run previous 24 hours, during which wildland fires were observed from satellites has been included recently. This study focuses on the effort performed to minimize the error in NAQFC PM2.5 predictions

  5. Modelling Variable Fire Severity in Boreal Forests: Effects of Fire Intensity and Stand Structure.

    Science.gov (United States)

    Miquelajauregui, Yosune; Cumming, Steven G; Gauthier, Sylvie

    2016-01-01

    It is becoming clear that fires in boreal forests are not uniformly stand-replacing. On the contrary, marked variation in fire severity, measured as tree mortality, has been found both within and among individual fires. It is important to understand the conditions under which this variation can arise. We integrated forest sample plot data, tree allometries and historical forest fire records within a diameter class-structured model of 1.0 ha patches of mono-specific black spruce and jack pine stands in northern Québec, Canada. The model accounts for crown fire initiation and vertical spread into the canopy. It uses empirical relations between fire intensity, scorch height, the percent of crown scorched and tree mortality to simulate fire severity, specifically the percent reduction in patch basal area due to fire-caused mortality. A random forest and a regression tree analysis of a large random sample of simulated fires were used to test for an effect of fireline intensity, stand structure, species composition and pyrogeographic regions on resultant severity. Severity increased with intensity and was lower for jack pine stands. The proportion of simulated fires that burned at high severity (e.g. >75% reduction in patch basal area) was 0.80 for black spruce and 0.11 for jack pine. We identified thresholds in intensity below which there was a marked sensitivity of simulated fire severity to stand structure, and to interactions between intensity and structure. We found no evidence for a residual effect of pyrogeographic region on simulated severity, after the effects of stand structure and species composition were accounted for. The model presented here was able to produce variation in fire severity under a range of fire intensity conditions. This suggests that variation in stand structure is one of the factors causing the observed variation in boreal fire severity.

  6. Disaster Analysis: Police and Fire Departments. Phase 2.

    Science.gov (United States)

    1989-03-01

    W6 9RS ENGLAND Proteccion Civil c/Evaristo 5 Miguel 8 28008 Madrid, SPAIN Hubert Williams Police Foundation 1001 22nd Street NW Suite 200 Washington...operations during natural and technological disasters; the remaining 24 studies examined police or fire response to riots or civil disturbances. Of the 26...but instead focus upon either general police activity (Wilson, 1968) or police operations during civil disturbances (Westley, 1957; Masotti and Bowen

  7. Investigation of Turbulators for Fire Tube Boilers Using Exergy Analysis

    OpenAIRE

    AYHAN, Betül

    2001-01-01

    In this paper, an experimental study of five different types of ``turbulator" inserts for fire tube boilers is presented. The experimental setup was constructed in the Department of Mechanical Engineering Laboratory of Karadeniz Technical University. It was tested to evaluate the boiler efficiency according to TS 4040 standard, and to evaluate the second law efficiency of thermodynamics for the cases with and without inserts under the same operating conditions. Four new typ...

  8. Simulation modeling and analysis with Arena

    CERN Document Server

    Altiok, Tayfur

    2007-01-01

    Simulation Modeling and Analysis with Arena is a highly readable textbook which treats the essentials of the Monte Carlo discrete-event simulation methodology, and does so in the context of a popular Arena simulation environment.” It treats simulation modeling as an in-vitro laboratory that facilitates the understanding of complex systems and experimentation with what-if scenarios in order to estimate their performance metrics. The book contains chapters on the simulation modeling methodology and the underpinnings of discrete-event systems, as well as the relevant underlying probability, statistics, stochastic processes, input analysis, model validation and output analysis. All simulation-related concepts are illustrated in numerous Arena examples, encompassing production lines, manufacturing and inventory systems, transportation systems, and computer information systems in networked settings.· Introduces the concept of discrete event Monte Carlo simulation, the most commonly used methodology for modeli...

  9. Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow.

    Science.gov (United States)

    Hu, L H; Huo, R; Yang, D

    2009-07-15

    The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons--a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

  10. Experimental and numerical analysis of the cooling performance of water spraying systems during a fire.

    Directory of Open Access Journals (Sweden)

    YaoHan Chen

    Full Text Available The water spray systems are effective protection systems in the confined or unconfined spaces to avoid the damage to building structures since the high temperature when fires occur. NFPA 15 and 502 have suggested respectively that the factories or vehicle tunnels install water spray systems to protect the machinery and structures. This study discussed the cooling effect of water spray systems in experimental and numerical analyses. The actual combustion of woods were compared with the numerical simulations. The results showed that although the flame continued, the cooling effects by water spraying process within 120 seconds were obvious. The results also indicated that the simulation results of the fifth version Fire Dynamics Simulator (FDS overestimated the space temperature before water spraying in the case of the same water spray system.

  11. Analysis of Petroleum Products in Fire Debris Residues by Gas Chromatography: A Literature Review

    Directory of Open Access Journals (Sweden)

    Gurvinder Singh Bumbrah

    2017-06-01

    Full Text Available This review gives a brief overview of developments in the analysis of petroleum products (PP in fire debris residues (FDR by gas chromatography (GC. The review covers different aspects of analysis such as the substrates involved, isolation procedures, column and mobile phase used, and subsequent detection in tabular form. This paper covers detection of PP such as petrol, kerosene, and diesel in various types’ of samples of interest to fire debris analysts. Solid phase microextraction is most frequently used along with gas chromatography-mass spectrometry (GC-MS for the extraction and identification of PP from FDR. Chemometric tools should be used to improve the significance and reliability of results obtained from the analysis of FDR. However, the potential utility of portable GC-MS in fire debris analysis cannot be ignored, and its proper development and validation is required before using it for this purpose.

  12. The effects of model composition design choices on high-fidelity simulations of motoneuron recruitment and firing behaviors.

    Science.gov (United States)

    Allen, John M; Elbasiouny, Sherif M

    2017-11-28

    Computational models often require tradeoffs, such as balancing detail with efficiency; yet optimal balance should incorporate sound design features that do not bias the results of the specific scientific question under investigation. The present study examines how model design choices impact simulation results. We developed a rigorously-validated high-fidelity computational model of the spinal motoneuron pool to study three long-standing model design practices which have yet to be examined for their impact on motoneuron recruitment, firing rate, and force simulations. The practices examined were the use of: 1) Generic cell models to simulate different motoneuron types, 2) discrete property ranges for different motoneuron types, and 3) biological homogeneity of cell properties within motoneuron types. Our results show that each of these practices accentuates conditions of motoneuron recruitment based on the size principle, and minimizes conditions of mixed and reversed recruitment orders, which have been observed in animal and human recordings. Specifically, strict motoneuron orderly size recruitment occurs, but in a compressed range, after which mixed and reverse motoneuron recruitment occurs due to the overlap in electrical properties of different motoneuron types. Additionally, these practices underestimate the motoneuron firing rates and force data simulated by existing models. Our results indicate that current modeling practices increase conditions of motoneuron recruitment based on the size principle, and decrease conditions of mixed and reversed recruitment order, which, in turn, impacts the predictions made by existing models on motoneuron recruitment, firing rate, and force. Additionally, mixed and reverse motoneuron recruitment generated higher muscle force than orderly size motoneuron recruitment in these simulations and represents one potential scheme to increase muscle efficiency. The examined model design practices, as well as the present results, are

  13. Numerical simulation on behaviour of timber-concrete composite beams in fire

    Science.gov (United States)

    Du, Hao; Hu, Xiamin; Zhang, Bing; Minli, Yao

    2017-08-01

    This paper established sequentially coupled thermal-mechanical models of timber--concrete composite (TCC) beams by finite element software ANSYS to investigate the fire resistance of TCC beam. Existing experimental results were used to verify the coupled thermal-mechanical model. The influencing parameters consisted of the width of timber beam, the thickness of the concrete slab and the timber board. Based on the numerical results, the effects of these parameters on fire resistance of TCC beams were investigated in detail. The results showed that modeling results agreed well with test results, and verified the reliability of the finite element model. The width of the timber beam had a significant influence on the fire resistance of TCC beams. The fire resistance of TCC beams would be enhanced by increasing the width of timber beam, the thickness of concrete slab and the timber board.

  14. Analysis of pressurization of plutonium oxide storage vials during a postulated fire

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.; Kesterson, M.; Hensel, S.

    2015-02-10

    The documented safety analysis for the Savannah River Site evaluates the consequences of a postulated 1000 °C fire in a glovebox. The radiological dose consequences for a pressurized release of plutonium oxide powder during such a fire depend on the maximum pressure that is attained inside the oxide storage vial. To enable evaluation of the dose consequences, pressure transients and venting flow rates have been calculated for exposure of the storage vial to the fire. A standard B vial with a capacity of approximately 8 cc was selected for analysis. The analysis compares the pressurization rate from heating and evaporation of moisture adsorbed onto the plutonium oxide contents of the vial with the pressure loss due to venting of gas through the threaded connection between the vial cap and body. Tabulated results from the analysis include maximum pressures, maximum venting velocities, and cumulative vial volumes vented during the first 10 minutes of the fire transient. Results are obtained for various amounts of oxide in the vial, various amounts of adsorbed moisture, different vial orientations, and different surface fire exposures.

  15. Influences of coupled fire-atmosphere interaction on wildfire behavior

    Science.gov (United States)

    Linn, R.; Winterkamp, J.; Jonko, A. K.; Runde, I.; Canfield, J.; Parsons, R.; Sieg, C.

    2017-12-01

    Two-way interactions between fire and the environment affect fire behavior at scales ranging from buoyancy-induced mixing and turbulence to fire-scale circulations that retard or increase fire spread. Advances in computing have created new opportunities for the exploration of coupled fire-atmosphere behavior using numerical models that represent interactions between the dominant processes driving wildfire behavior, including convective and radiative heat transfer, aerodynamic drag and buoyant response of the atmosphere to heat released by the fire. Such models are not practical for operational, faster-than-real-time fire prediction due to their computational and data requirements. However, they are valuable tools for exploring influences of fire-atmosphere feedbacks on fire behavior as they explicitly simulate atmospheric motions surrounding fires from meter to kilometer scales. We use the coupled fire-atmosphere model FIRETEC to gain new insights into aspects of fire behavior that have been observed in the field and laboratory, to carry out sensitivity analysis that is impractical through observations and to pose new hypotheses that can be tested experimentally. Specifically, we use FIRETEC to study the following multi-scale coupled fire-atmosphere interactions: 1) 3D fire-atmosphere interaction that dictates multi-scale fire line dynamics; 2) influence of vegetation heterogeneity and variability in wind fields on predictability of fire spread; 3) fundamental impacts of topography on fire spread. These numerical studies support new conceptual models for the dominant roles of multi-scale fluid dynamics in determining fire spread, including the roles of crosswind fire line-intensity variations on heat transfer to unburned fuels and the role of fire line depth expansion in upslope acceleration of fires.

  16. Agent Based Simulation Output Analysis

    Science.gov (United States)

    2011-12-01

    over long periods of time) not to have a steady state, but apparently does. These simulation models are available free from sigmawiki.com 2.1...are used in computer animations and movies (for example, in the movie Jurassic Park) as well as to look for emergent social behavior in groups

  17. Modeling Urban Fire Growth,

    Science.gov (United States)

    Nuclear explosion damage, *Explosion effects, *Fires, *Flame propagation, Growth (General), Area coverage, Ignition, Combustion, Casualties...Computerized simulation, Predictions, Countermeasures, Fire suppression, Damage assessment, Urban areas, Vulnerability, Data acquisition, Methodology, Symposia

  18. A coupled thermo-hygro-chemo-mechanical model for the simulation of spalling of concrete subjected to fire loading

    Directory of Open Access Journals (Sweden)

    Zeiml M.

    2013-09-01

    Full Text Available The presented research work contributes to the realistic simulation of the stress state within fire-loaded concrete in order to attain insight into the development and occurrence of the critical state right before and during the event of spalling. A coupled thermo-hygro-chemo-mechanical code simulating the stress state as a consequence of both thermo-hygral and thermo-mechanical processes is presented together with an embedded strong-discontinuity model which is capable of capturing and tracking the propagation of a crack evolving in concrete as a quasi-brittle material. Combination of the two mentioned models is currently under way. With the resulting coupled model, it will be possible to take into account all major couplings, allowing to realistically simulate the spalling process.

  19. Long-term changes in soil erosion due to forest fires. A rainfall simulation approach in Eastern Spain

    Science.gov (United States)

    Cerdà, Artemi; Keesstra, Saskia; Pereira, Paulo; Matrix-Solera, Jorge; Giménez-Morera, Antonio; Úbeda, Xavier; Francos, Marcos; Alcañiz, Meritxell; Jordán, Antonio

    2016-04-01

    Soils are affected by the impacts of wildfires (Dlapa et al., 2013; Pereira et al., 2014; Tsibart et al., 2014; Dlapa et al., 2015, Hedo et al., 2015; Tessler et al., 2015). Soil erosion rates are highly affected by forest fires due to the removal of the above ground vegetation, the heat impact on the soil, the reduction of the organic matter, the ash cover, and the changes introduced by the rainfall on the soil surface (Lasanta and Cerdà, 2005; Mataix-Solera et al., 2011; Novara et al., 2011; Novara et al., 2013; Keesstra et al., 2014; Hedo et al., 2015; Pereira, 2015). Most of the research carried out on forest fire affected land paid attention to the "window of disturbance", which is the period that the soil losses are higher than before the forest fire and that last for few years (Cerdà, 1998a; Cerdà 1998b, Pérez-Cabello et al., 2011; Bodí et al., 2011; Bodí et al., 2012; Pereira et al., 2013: Pereira et al., 2015). However, the spatial and temporal variability of soil erosion is very high as a result of the uneven temporal and spatial distribution of the rainfall (Novara et al., 2011; Bisantino et al., 2015; Gessesse et al., 2015; Ochoa et al., 2015), and the window of disturbance cannot be easily found under natural rainfall. In order to understand the evolution of soil erosion after forest fires it is necessary to monitor fire affected sites over a long period of time, which will enable the assessment of the period affected by the window of disturbance (see Cerdà and Doerr, 2005). However, it is also possible to do measurements and experiments in areas with a different fire history. This will give us information about the temporal changes in soil erosion after forest fire. To reduce the spatial variability of rainfall we can use simulated rainfall that can be applied at multiple site with the same rainfall intensity and duration. For this purpose rainfall simulation can be of great help, in the laboratory (Moreno et al., 2014; Sadegui et al., 2015

  20. Testing of one-inch UF{sub 6} cylinder valves under simulated fire conditions

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, P.G. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    Accurate computational models which predict the behavior of UF{sub 6} cylinders exposed to fires are required to validate existing firefighting and emergency response procedures. Since the cylinder valve is a factor in the containment provided by the UF{sub 6} cylinder, its behavior under fire conditions has been a necessary assumption in the development of such models. Consequently, test data is needed to substantiate these assumptions. Several studies cited in this document provide data related to the behavior of a 1-inch UF{sub 6} cylinder valve in fire situations. To acquire additional data, a series of tests were conducted at the Paducah Gaseous Diffusion Plant (PGDP) under a unique set of test conditions. This document describes this testing and the resulting data.

  1. Holistic Nursing Simulation: A Concept Analysis.

    Science.gov (United States)

    Cohen, Bonni S; Boni, Rebecca

    2018-03-01

    Simulation as a technology and holistic nursing care as a philosophy are two components within nursing programs that have merged during the process of knowledge and skill acquisition in the care of the patients as whole beings. Simulation provides opportunities to apply knowledge and skill through the use of simulators, standardized patients, and virtual settings. Concerns with simulation have been raised regarding the integration of the nursing process and recognizing the totality of the human being. Though simulation is useful as a technology, the nursing profession places importance on patient care, drawing on knowledge, theories, and expertise to administer patient care. There is a need to promptly and comprehensively define the concept of holistic nursing simulation to provide consistency and a basis for quality application within nursing curricula. This concept analysis uses Walker and Avant's approach to define holistic nursing simulation by defining antecedents, consequences, and empirical referents. The concept of holism and the practice of holistic nursing incorporated into simulation require an analysis of the concept of holistic nursing simulation by developing a language and model to provide direction for educators in design and development of holistic nursing simulation.

  2. Does Suspected Sleep Disordered Breathing Impact on the Sleep and Performance of Firefighting Volunteers during a Simulated Fire Ground Campaign?

    Directory of Open Access Journals (Sweden)

    Sarah M. Jay

    2016-01-01

    Full Text Available Adequate sleep is fundamental to workplace performance. For volunteer firefighters who work in safety critical roles, poor performance at work can be life threatening. Extended shifts and sleeping conditions negatively impact sleep during multi-day fire suppression campaigns. Having sleep disordered breathing (SDB could contribute further to sleep deficits. Our aim was to investigate whether those with suspected SDB slept and performed more poorly during a fire ground simulation involving sleep restriction. Participants, n = 20 participated in a 3-day-4-night fire ground simulation. Based on oximetry desaturation index data collected during their participation, participants were retrospectively allocated to either a SDB (n = 8 or a non-SDB group (n = 12. The simulation began with an 8 h Baseline sleep (BL followed by two nights of restricted (4 h sleep and an 8 h recovery sleep (R. All sleeps were recorded using a standard electroencephalography (EEG montage as well as oxygen saturation. During the day, participants completed neurobehavioral (response time, lapses and subjective fatigue tasks. Mixed effects ANOVA were used to compare differences in sleep and wake variables. Analyses revealed a main effect of group for Total sleep (TST, REM , wake after sleep onset (WASO and Arousals/h with the SDB group obtaining less TST and REM and greater WASO and Arousals/h. The group × night interaction was significant for N3 with the SDB group obtaining 42 min less during BL. There was a significant main effect of day for RRT, lapses and subjective fatigue and a significant day × group interaction for RRT. Overall, the SDB group slept less, experienced more disturbed sleep and had poorer response time performance, which was exacerbated by the second night of sleep restriction. This could present a safety concern, particularly during longer campaigns and is worthy of further investigation. In addition, we would recommend promotion of awareness of SDB, its

  3. Design and analysis of the federal aviation administration next generation fire test burner

    Science.gov (United States)

    Ochs, Robert Ian

    The United States Federal Aviation Administration makes use of threat-based fire test methods for the certification of aircraft cabin materials to enhance the level of safety in the event of an in-flight or post-crash fire on a transport airplane. The global nature of the aviation industry results in these test methods being performed at hundreds of laboratories around the world; in some cases testing identical materials at multiple labs but yielding different results. Maintenance of this standard for an elevated level of safety requires that the test methods be as well defined as possible, necessitating a comprehensive understanding of critical test method parameters. The tests have evolved from simple Bunsen burner material tests to larger, more complicated apparatuses, requiring greater understanding of the device for proper application. The FAA specifies a modified home heating oil burner to simulate the effects of large, intense fires for testing of aircraft seat cushions, cargo compartment liners, power plant components, and thermal acoustic insulation. Recently, the FAA has developed a Next Generation (NexGen) Fire Test burner to replace the original oil burner that has become commercially unavailable. The NexGen burner design is based on the original oil burner but with more precise control of the air and fuel flow rates with the addition of a sonic nozzle and a pressurized fuel system. Knowledge of the fundamental flow properties created by various burner configurations is desired to develop an updated and standardized burner configuration for use around the world for aircraft materials fire testing and airplane certification. To that end, the NexGen fire test burner was analyzed with Particle Image Velocimetry (PIV) to resolve the non-reacting exit flow field and determine the influence of the configuration of burner components. The correlation between the measured flow fields and the standard burner performance metrics of flame temperature and

  4. Using thermal analysis to evaluate the fire effects on organic matter content of Andisols

    Directory of Open Access Journals (Sweden)

    J. Neris

    2013-09-01

    Full Text Available Soil organic compounds play a relevant role in aggregate stability and thus, in the susceptibility of soils to erosion. Thermal analysis (N2 and air and chemical oxidation techniques (dichromate and permanganate oxidation were used to evaluate the effects of a forest fire on the organic matter of Andisols. Both thermal analysis and chemical methods showed a decrease in the organic matter content and an increase in the recalcitrance of the remaining organic compounds in the burned zones. Thermal analysis indicated an increase in the thermal stability of the organic compounds of fire-affected soils and a lower content of both labile and recalcitrant pools as a consequence of the fire. However, this decrease was relatively higher in the labile pool and lower in the recalcitrant one, indicative of an increase in the recalcitrance of the remaining organic compounds. Apparently, black carbon did not burn under our experimental conditions. Under N2, the results showed a lower labile and a higher recalcitrant and refractory contents in burned and some unburned soils, possibly due to the lower decomposition rate under N2 flux. Thermal analysis using O2 and the chemical techniques showed a positive relation, but noticeable differences in the total amount of the labile pool. Thermal analysis methods provide direct quantitative information useful to characterize the soil organic matter quality and to evaluate the effects of fire on soils.

  5. Quantitative Analysis of Mixed Halogen Dioxins and Furans in Fire Debris Utilizing Atmospheric Pressure Ionization Gas Chromatography-Triple Quadrupole Mass Spectrometry.

    Science.gov (United States)

    Organtini, Kari L; Myers, Anne L; Jobst, Karl J; Reiner, Eric J; Ross, Brian; Ladak, Adam; Mullin, Lauren; Stevens, Douglas; Dorman, Frank L

    2015-10-20

    Residential and commercial fires generate a complex mixture of volatile, semivolatile, and nonvolatile compounds. This study focused on the semi/nonvolatile components of fire debris to better understand firefighter exposure risks. Using the enhanced sensitivity of gas chromatography coupled to atmospheric pressure ionization-tandem mass spectrometry (APGC-MS/MS), complex fire debris samples collected from simulation fires were analyzed for the presence of potentially toxic polyhalogenated dibenzo-p-dioxins and dibenzofurans (PXDD/Fs and PBDD/Fs). Extensive method development was performed to create multiple reaction monitoring (MRM) methods for a wide range of PXDD/Fs from dihalogenated through hexa-halogenated homologue groups. Higher halogenated compounds were not observed due to difficulty eluting them off the long column used for analysis. This methodology was able to identify both polyhalogenated (mixed bromo-/chloro- and polybromo-) dibenzo-p-dioxins and dibenzofurans in the simulated burn study samples collected, with the dibenzofuran species being the dominant compounds in the samples. Levels of these compounds were quantified as total homologue groups due to the limitations of commercial congener availability. Concentration ranges in household simulation debris were observed at 0.01-5.32 ppb (PXDFs) and 0.18-82.11 ppb (PBDFs). Concentration ranges in electronics simulation debris were observed at 0.10-175.26 ppb (PXDFs) and 0.33-9254.41 ppb (PBDFs). Samples taken from the particulate matter coating the firefighters' helmets contained some of the highest levels of dibenzofurans, ranging from 4.10 ppb to 2.35 ppm. The data suggest that firefighters and first responders at fire scenes are exposed to a complex mixture of potentially hundreds to thousands of different polyhalogenated dibenzo-p-dioxins and dibenzofurans that could negatively impact their health.

  6. Fire safety

    International Nuclear Information System (INIS)

    Keski-Rahkonen, O.; Bjoerkman, J.; Hostikka, S.; Mangs, J.; Huhtanen, R.; Palmen, H.; Salminen, A.; Turtola, A.

    1998-01-01

    According to experience and probabilistic risk assessments, fires present a significant hazard in a nuclear power plant. Fires may be initial events for accidents or affect safety systems planned to prevent accidents and to mitigate their consequences. The project consists of theoretical work, experiments and simulations aiming to increase the fire safety at nuclear power plants. The project has four target areas: (1) to produce validated models for numerical simulation programmes, (2) to produce new information on the behavior of equipment in case of fire, (3) to study applicability of new active fire protecting systems in nuclear power plants, and (4) to obtain quantitative knowledge of ignitions induced by important electric devices in nuclear power plants. These topics have been solved mainly experimentally, but modelling at different level is used to interpret experimental data, and to allow easy generalisation and engineering use of the obtained data. Numerical fire simulation has concentrated in comparison of CFD modelling of room fires, and fire spreading on cables on experimental data. So far the success has been good to fair. A simple analytical and numerical model has been developed for fire effluents spreading beyond the room of origin in mechanically strongly ventilated compartments. For behaviour of equipment in fire several full scale and scaled down calorimetric experiments were carried out on electronic cabinets, as well as on horizontal and vertical cable trays. These were carried out to supply material for CFD numerical simulation code validation. Several analytical models were developed and validated against obtained experimental results to allow quick calculations for PSA estimates as well as inter- and extrapolations to slightly different objects. Response times of different commercial fire detectors were determined for different types of smoke, especially emanating from smoldering and flaming cables to facilitate selection of proper detector

  7. Numerical prediction of heat-flux to massive calorimeters engulfed in regulatory fires with the cask analysis fire environment (CAFE) model

    International Nuclear Information System (INIS)

    Koski, Jorman A.; Suo-Antitla, Ahti; Kramer M, Alex; Greiner, Miles

    2000-01-01

    Recent observations show that the thermal boundary conditions within large-scale fires are significantly affected by the presence of thermally massive objects. These objects cool the soot and gas near their surfaces, and these effects reduce the incoming radiant heat-flux to values lower than the levels expected from simple σT fire 4 models. They also affect the flow and temperature fields in the fire far from their surfaces. The Cask Analysis Fire Environment (CAFE) code has been developed at Sandia National Laboratories to provide an enhanced fire boundary condition for the design of radioactive material packages. CAFE is a set of computer subroutines that use computational fluid mechanics methods to predict convective heat transfer and mixing. It also includes models for fuel and oxygen transport, chemical reaction, and participating-media radiation heat transfer. This code uses two-dimensional computational models so that it has reasonably short turnaround times on standard workstations and is well suited for design and risk studies. In this paper, CAFE is coupled with a commercial finite-element program to model a large cylindrical calorimeter fully engulfed in a pool fire. The time-dependent heat-flux to the calorimeter and the calorimeter surface temperature are determined for several locations around the calorimeter circumference. The variation of heat-flux with location is determined for calorimeters with different diameters and wall thickness, and the observed effects discussed

  8. Performance of a Protected Wireless Sensor Network in a Fire. Analysis of Fire Spread and Data Transmission

    Directory of Open Access Journals (Sweden)

    Frederic Morandini

    2009-07-01

    Full Text Available The paper deals with a Wireless Sensor Network (WSN as a reliable solution for capturing the kinematics of a fire front spreading over a fuel bed. To provide reliable information in fire studies and support fire fighting strategies, a Wireless Sensor Network must be able to perform three sequential actions: 1 sensing thermal data in the open as the gas temperature; 2 detecting a fire i.e., the spatial position of a flame; 3 tracking the fire spread during its spatial and temporal evolution. One of the great challenges in performing fire front tracking with a WSN is to avoid the destruction of motes by the fire. This paper therefore shows the performance of Wireless Sensor Network when the motes are protected with a thermal insulation dedicated to track a fire spreading across vegetative fuels on a field scale. The resulting experimental WSN is then used in series of wildfire experiments performed in the open in vegetation areas ranging in size from 50 to 1,000 m².

  9. Performance of a protected wireless sensor network in a fire. Analysis of fire spread and data transmission.

    Science.gov (United States)

    Antoine-Santoni, Thierry; Santucci, Jean-François; de Gentili, Emmanuelle; Silvani, Xavier; Morandini, Frederic

    2009-01-01

    The paper deals with a Wireless Sensor Network (WSN) as a reliable solution for capturing the kinematics of a fire front spreading over a fuel bed. To provide reliable information in fire studies and support fire fighting strategies, a Wireless Sensor Network must be able to perform three sequential actions: 1) sensing thermal data in the open as the gas temperature; 2) detecting a fire i.e., the spatial position of a flame; 3) tracking the fire spread during its spatial and temporal evolution. One of the great challenges in performing fire front tracking with a WSN is to avoid the destruction of motes by the fire. This paper therefore shows the performance of Wireless Sensor Network when the motes are protected with a thermal insulation dedicated to track a fire spreading across vegetative fuels on a field scale. The resulting experimental WSN is then used in series of wildfire experiments performed in the open in vegetation areas ranging in size from 50 to 1,000 m(2).

  10. Advanced concept for damage control : A framework to simulate fire propagation and damage control effects

    NARCIS (Netherlands)

    Gillis, M.P.W.; Keijer, W.; Smit, C.S.

    2003-01-01

    Current damage control procedures are developed on the basis of a long-standing experience. However there are reasons to believe that these procedures do not account for major weapon-induced calamities. Fire fighting after substantial blast and fragmentation damage, due to a weaponhit, is quite

  11. Directional excitation of Rg due to ripple-fired explosions: 2-Dimensional finite-difference simulations

    International Nuclear Information System (INIS)

    Jih, Rong-Song

    1993-01-01

    A major issue for the Non-Proliferation Treaty is the discrimination of large chemical explosions from possible clandestine or small nuclear tests. Unless discrimination is possible, the numerous mining blasts could give ample opportunity for concealing clandestine tests. Ripple-fired explosions are commonly used to fragment rocks during quarry and open-pit mining. The periodicity inherent in the ripple firing could produce a seismic reinforcement at the frequency of the delay between shots or rows. It has been suggested that the convolution of a single explosion with a comb function of variable spacing and variable amplitude can be used to model the distinctive signature of ripple firing. Baumgardt and Ziegler (1988) delicately demonstrated that the incoherent array-stack spectra can be used to identify some multiple shots recorded at NORSAR. By superpositioning the waveform due to a single shot with proper time delay, they were able to model the source multiplicity under the assumption that the spatial spreading of the shots is negligible with respect to the distance to the receiver. The work by Stump et al. successfully characterized the major features of the wavefield due to ripple firings at near-source ranges

  12. Numerical simulation of crown fire hazard following bark beetle-caused mortality in lodgepole pine forests

    Science.gov (United States)

    Chad Hoffman; Russell Parsons; Penny Morgan; Ruddy Mell

    2010-01-01

    The purpose of this study is to investigate how varying amounts of MPB-induced tree mortality affects the amount of crown fuels consumed and the fire intensity across a range of lodgepole pine stands of different tree density and spatial arrangements during the early stages of a bark beetle outbreak. Unlike past studies which have relied on semi-empirical or empirical...

  13. Smoke simulation for fire engineering using a multigrid method on graphics hardware

    DEFF Research Database (Denmark)

    Glimberg, Stefan; Erleben, Kenny; Bennetsen, Jens

    2009-01-01

    We present a GPU-based Computational Fluid Dynamics solver for the purpose of fire engineering. We apply a multigrid method to the Jacobi solver when solving the Poisson pressure equation, supporting internal boundaries. Boundaries are handled on the coarse levels, ensuring that boundaries will n...

  14. Fire and simulated herbivory have antagonistic effects on resistance of savanna grasslands to alien shrub invasion

    NARCIS (Netherlands)

    te Beest, Mariska; Mpandza, Nokukhanya J.; Olff, Han

    Question Resistance of the native community has been identified as an important factor limiting invasion success and invader impact. However, to what extent resistance interacts with disturbance to control invasion success remains unclear. We studied the interaction between biotic resistance, fire

  15. Simulating fuel treatment effects in dry forests of the western United States: testing the principles of a fire-safe forest

    Science.gov (United States)

    Morris C. Johnson; Maureen C Kennedy; David L. Peterson

    2011-01-01

    We used the Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS) to simulate fuel treatment effects on stands in low- to midelevation dry forests (e.g., ponderosa pine (Pinus ponderosa Dougl. ex. P. & C. Laws.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) of the western United States. We...

  16. Detector Simulation: Data Treatment and Analysis Methods

    CERN Document Server

    Apostolakis, J

    2011-01-01

    Detector Simulation in 'Data Treatment and Analysis Methods', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '4.1 Detector Simulation' of Chapter '4 Data Treatment and Analysis Methods' with the content: 4.1 Detector Simulation 4.1.1 Overview of simulation 4.1.1.1 Uses of detector simulation 4.1.2 Stages and types of simulation 4.1.2.1 Tools for event generation and detector simulation 4.1.2.2 Level of simulation and computation time 4.1.2.3 Radiation effects and background studies 4.1.3 Components of detector simulation 4.1.3.1 Geometry modeling 4.1.3.2 External fields 4.1.3.3 Intro...

  17. Fire hazards analysis for the replacement cross-site transfer system, project W-058

    International Nuclear Information System (INIS)

    Sepahpur, J.B.

    1996-01-01

    The fire hazards analysis assess the risk from fire and determines compliance with the applicable criteria of DOE 5480.7A, DOE 6430.1A, and RLID 5480.7. (Project W-058 will provide encased pipelines to connect the SY Tank Farms in 200 West Area with the tank farms in 200 East Area via an interface with the 244-A lift station. Function of the cross-site transfer system will be to transfer radioactive waste from the SY Tank Farm to treatment, storage, and disposal facilities in 200 East Area.)

  18. Analysis and study on the membrane method of CO2 removal of coal-fired boilers

    International Nuclear Information System (INIS)

    Fangqin, Li; Henan, Li; Jianxing, Ren; Jiang, Wu; Zhongzhu, Qiu

    2010-01-01

    Carbon dioxide (CO 2 ) is one kind of harmful substances from the burning process of fossil fuel. CO 2 emissions cause serious pollution on atmospheric environment, especially greenhouse effect. In this paper, CO 2 formation mechanism and control methods were researched. Membrane technology was studied to control CO 2 emissions from coal-fired boilers. The relationship between CO 2 removal efficiency and parameters of membrane contactor was analyzed. Through analysis and study, factors affecting on CO 2 removal efficiency were gotten. How to choose the best parameters was known. This would provide theoretical basis for coal-fired utility boilers choosing effective way of CO 2 removal. (author)

  19. Preliminary fire hazard analysis for the PUTDR and TRU trenches in the Solid Waste Burial Ground

    International Nuclear Information System (INIS)

    Gaschott, L.J.

    1995-01-01

    This document represents the Preliminary Fire Hazards Analysis for the Pilot Unvented TRU Drum Retrieval effort and for the Transuranic drum trenches in the low level burial grounds. The FHA was developed in accordance with DOE Order 5480.7A to address major hazards inherent in the facility

  20. Allowable Stresses For Use in Dynamic Analysis of PF-4 Fire Suppression System Piping

    Energy Technology Data Exchange (ETDEWEB)

    Menefee, Maia Catherine [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Salmon, Michael W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-30

    The purpose of this paper is to present the results of a limited test program performed on samples of fittings removed from the PF-4 fire suppression system and to present recommendations for allowable stresses to be used in subsequent piping analysis.

  1. Thermal analysis of GFRP-reinforced continuous concrete decks subjected to top fire

    Science.gov (United States)

    Hawileh, Rami A.; Rasheed, Hayder A.

    2017-12-01

    This paper presents a numerical study that investigates the behavior of continuous concrete decks doubly reinforced with top and bottom glass fiber reinforced polymer (GFRP) bars subjected to top surface fire. A finite element (FE) model is developed and a detailed transient thermal analysis is performed on a continuous concrete bridge deck under the effect of various fire curves. A parametric study is performed to examine the top cover thickness and the critical fire exposure curve needed to fully degrade the top GFRP bars while achieving certain fire ratings for the deck considered. Accordingly, design tables are prepared for each fire curve to guide the engineer to properly size the top concrete cover and maintain the temperature in the GFRP bars below critical design values in order to control the full top GFRP degradation. It is notable to indicate that degradation of top GFRP bars do not pose a collapse hazard but rather a serviceability concern since cracks in the negative moment region widen resulting in simply supported spans.

  2. Simulating effects of fire disturbance and climate change on boreal forest productivity and evapotranspiration

    International Nuclear Information System (INIS)

    Kang, Sinkyu; Kimball, John S.; Running, Steven W.

    2006-01-01

    We used a terrestrial ecosystem process model, BIOME-BGC, to investigate historical climate change and fire disturbance effects on regional carbon and water budgets within a 357,500 km 2 portion of the Canadian boreal forest. Historical patterns of increasing atmospheric CO 2 , climate change, and regional fire activity were used as model drivers to evaluate the relative effects of these impacts to spatial patterns and temporal trends in forest net primary production (NPP) and evapotranspiration (ET). Historical trends of increasing atmospheric CO 2 resulted in overall 13% and 5% increases in annual NPP and ET from 1994 to 1996, respectively. NPP was found to be relatively sensitive to changes in air temperature (T a ), while ET was more sensitive to precipitation (P) change within the ranges of observed climate variability (e.g., +/-2 o C for T a and +/-20% for P). In addition, the potential effect of climate change related warming on NPP is exacerbated or offset depending on whether these changes are accompanied by respective decreases or increases in precipitation. Historical fire activity generally resulted in reductions of both NPP and ET, which consumed an average of approximately 6% of annual NPP from 1959 to 1996. Areas currently occupied by dry conifer forests were found to be subject to more frequent fire activity, which consumed approximately 8% of annual NPP. The results of this study show that the North American boreal ecosystem is sensitive to historical patterns of increasing atmospheric CO 2 , climate change and regional fire activity. The relative impacts of these disturbances on NPP and ET interact in complex ways and are spatially variable depending on regional land cover and climate gradients. (author)

  3. Estimating canopy bulk density and canopy base height for conifer stands in the interior Western United States using the Forest Vegetation Simulator Fire and Fuels Extension.

    Science.gov (United States)

    Seth Ex; Frederick Smith; Tara Keyser; Stephanie Rebain

    2017-01-01

    The Forest Vegetation Simulator Fire and Fuels Extension (FFE-FVS) is often used to estimate canopy bulk density (CBD) and canopy base height (CBH), which are key indicators of crown fire hazard for conifer stands in the Western United States. Estimated CBD from FFE-FVS is calculated as the maximum 4 m running mean bulk density of predefined 0.3 m thick canopy layers (...

  4. Comparisons of Ballistic Trajectory Simulations Using Artillery Meteorological Messages Derived from Local Balloon Data and Battlescale Forecast Model Data for the 1998 SADARM IOT&E Firings

    Science.gov (United States)

    2001-11-01

    Evaluation ( IOT &E) firings that occurred during the summer of 1998 at Fort Greeley, Alaska. Due to the complex terrain and local wind conditions encountered...in the test area during the IOT &E, the Met study was proposed as a way to evaluate current and future artillery Met forecasting capabilities to improve...SADARM targeting accuracy. This report includes Ballistic trajectory simulation analyses using raw and forecast Met values and corresponding actual impact data front the IOT &E firings.

  5. Energy release from pit fires for producing a fire model. Natural-scale analysis of energy release from pit fires for the purpose of establishing a fire model. Final report; Energiefreisetzung von Grubenbraenden zur Erstellung eines Brandmodell. Untersuchung ueber die Energiefreisetzung von Grubenbraenden im natuerlichen Massstab zur Erstellung eines Brandmodells. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Holke, K.; Michelis, J.

    1996-12-31

    In the context of the research project, measurements were made regarding the energy release in pit fires. The heat flow in fires with standard wood fire objects and in fires on conveyor belts in underground fire sections of the DMT Tremonia experimental pit was measured for this purpose. It was found that the distribution of the mean total heat flow in the roadway crossection depended on the geometric arrangement of the fire object. The belt fire tests carried out have shown that the heat flow depended on the burning behaviour of the belts and with increasing flame propagation on the conveyor belt, the mean heat flow increased. Further, the temperature effects after wood and conveyor belt fires were simulated with the modified `MFIRE` simulation program and were compared with the corresponding experimental results. (orig./MSK) [Deutsch] Im Rahmen des Untersuchungsvorhabens wurden Messungen bezueglich der Energiefreisetzung bei Grubenbraenden durchgefuehrt. Hierzu wurde der Waermefluss bei Braenden mit Standardholzbrandobjekten und bei Foerdergurtbraenden in den untertaegigen Brandstrecken der DMT-Versuchsgrube Tremonia gemessen. Es zeigte sich, dass die Verteilung des mittleren Gesamtwaermeflusses im Streckenquerschnitt von der geometrischen Anordnung des Brandobjektes abhing. Die durchgefuehrten Gurtbrandversuche haben ergeben, dass der Waermefluss vom Brandverhalten der Gurte abhing und mit zunehmender Flammenausbreitung am Foerdergurt der mittlere Waermefluss zunahm. Weiterhin wurden mit dem modifizierten Simulationsprogramm `MFIRE` die Temperaturauswirkungen hinter Holz- und Foerdergurtbraenden simuliert und mit den entsprechenden experimentellen Ergebnissen verglichen. (orig./MSK)

  6. Smoke injection heights from fires in North America: analysis of 5 years of satellite observations

    Directory of Open Access Journals (Sweden)

    M. Val Martin

    2010-02-01

    Full Text Available We analyze an extensive record of aerosol smoke plume heights derived from observations over North America for the fire seasons of 2002 and 2004–2007 made by the Multi-angle Imaging SpectroRadiometer (MISR instrument on board the NASA Earth Observing System Terra satellite. We characterize the magnitude and variability of smoke plume heights for various biomes, and assess the contribution of local atmospheric and fire conditions to this variability. Plume heights are highly variable, ranging from a few hundred meters up to 5000 m above the terrain at the Terra overpass time (11:00–14:00 local time. The largest plumes are found over the boreal region (median values of ~850 m height, 24 km length and 940 m thickness, whereas the smallest plumes are found over cropland and grassland fires in the contiguous US (median values of ~530 m height, 12 km length and 550–640 m thickness. The analysis of plume heights in combination with assimilated meteorological observations from the NASA Goddard Earth Observing System indicates that a significant fraction (4–12% of plumes from fires are injected above the boundary layer (BL, consistent with earlier results for Alaska and the Yukon Territories during summer 2004. Most of the plumes located above the BL (>83% are trapped within stable atmospheric layers. We find a correlation between plume height and the MODerate resolution Imaging Spectroradiometer (MODIS fire radiative power (FRP thermal anomalies associated with each plume. Smoke plumes located in the free troposphere (FT exhibit larger FRP values (1620–1640 MW than those remaining within the BL (174–465 MW. Plumes located in the FT without a stable layer reach higher altitudes and are more spread-out vertically than those associated with distinct stable layers (2490 m height and 2790 m thickness versus 1880 m height and 1800 m thickness. The MISR plume climatology exhibits a well-defined seasonal cycle of plume heights in boreal and

  7. In situ simulation - fire modeller. :Udfordringer og muligheder i arbejdspladslæring

    OpenAIRE

    Musaeus, Peter; Krogh, Kristian; Paltved, Charlotte

    2014-01-01

    IntroductionIn situ simulation is characterized by being situated inthe clinical environment as opposed to the simulationlaboratory. But in situ simulation bears a familyresemblance to other types of on the job training. Weexplore a typology of in situ simulation and suggest thatthere are four fruitful approaches to in situ simulation: (1)In situ simulation informed by reported critical incidentsand adverse events from emergency departments (ED)in which team training is about to be conducted ...

  8. Fire protection and hydrogen burn equipment survival research

    International Nuclear Information System (INIS)

    Berry, D.L.

    1985-01-01

    A discussion is presented of the Fire Protection and Hydrogen Burn Equipment Survival Research Programs at Sandia National Laboratories, with emphasis on the experimental efforts completed in FY85 to characterize fires and fire damage and to understand equipment response to hydrogen burns. The results of fire characterization tests, electrical cabinet fire tests, and cable and relay damage threshold tests are described. The results of hydrogen burn simulation tests of cable, solenoid valves, and pressure transmitters are also described, including testing using both realistic heat flux conditions and heat fluxes beyond those anticipated during an actual hydrogen burn. Plans for FY86 analysis and testing are summarized. 17 figs

  9. Determining Appropriate Seasonal Dislocation Sites of Fire Brigades in the Šibenik-Knin County Based on Road Network Analysis

    Directory of Open Access Journals (Sweden)

    Doroteja Držaić

    2015-07-01

    Full Text Available The majority of wildfires in the Republic of Croatia occur in coastal and island areas, so the Šibenik-Knin County was studied in this research. This research was based upon spatial and temporal analyses of past fires in the Šibenik-Knin County using GIS tools in order to identify potential locations for seasonal dislocation of fire stations. The research resulted in cartographic visualization of areas within reach of existing fire brigades within the standard intervention time and potential locations for seasonal dislocation of fire stations. The results obtained using spatial GIS analysis can be used as a basis for future spatial planning and seasonal dislocation of fire stations in the Šibenik-Knin County, as well as a basis for determining dislocation of fire stations in other Croatian counties.

  10. Formation of globular cluster candidates in merging proto-galaxies at high redshift: a view from the FIRE cosmological simulations

    Science.gov (United States)

    Kim, Ji-hoon; Ma, Xiangcheng; Grudić, Michael Y.; Hopkins, Philip F.; Hayward, Christopher C.; Wetzel, Andrew; Faucher-Giguère, Claude-André; Kereš, Dušan; Garrison-Kimmel, Shea; Murray, Norman

    2018-03-01

    Using a state-of-the-art cosmological simulation of merging proto-galaxies at high redshift from the FIRE project, with explicit treatments of star formation and stellar feedback in the interstellar medium, we investigate the formation of star clusters and examine one of the formation hypotheses of present-day metal-poor globular clusters. We find that frequent mergers in high-redshift proto-galaxies could provide a fertile environment to produce long-lasting bound star clusters. The violent merger event disturbs the gravitational potential and pushes a large gas mass of ≳ 105-6 M⊙ collectively to high density, at which point it rapidly turns into stars before stellar feedback can stop star formation. The high dynamic range of the reported simulation is critical in realizing such dense star-forming clouds with a small dynamical time-scale, tff ≲ 3 Myr, shorter than most stellar feedback time-scales. Our simulation then allows us to trace how clusters could become virialized and tightly bound to survive for up to ˜420 Myr till the end of the simulation. Because the cluster's tightly bound core was formed in one short burst, and the nearby older stars originally grouped with the cluster tend to be preferentially removed, at the end of the simulation the cluster has a small age spread.

  11. Fire exposure testing of encapsulated simulant radioactive wastes. Task 3 characterization of radioactive waste forms a series of final reports (1985-89) no. 13

    International Nuclear Information System (INIS)

    Wells, D.A.; Kenny, V.M.

    1991-01-01

    There are no regulations in the UK or elsewhere in the EC that deal specifically with storage fire accident criteria for ILWs. In order to establish such criteria and develop test methods it is pertinent to provide data on the behaviour of typical waste packages in severe fire accidents. This programme seeks to provide information on the performance of a range of waste types using full-scale non-radioactive simulated packaged wasteforms. The initial objective is to identify the test conditions for packages, which will allow interpolation of results rather than extrapolation, for fires in which drums of waste are directly exposed to a hydrocarbon pool fire, and those in which packages are in their transport overpacks leading to significantly lower heat fluxes. These conditions provide the experimental parameters for the execution of thermal tests to measure the performance of full-scale packages. This testwork can be split into two distinct categories: (a) Furnace test, representing a transport fire. In transport, drums are placed within an overpack that performs the function of a thermal barrier protecting the drums during a fire. (b) Pool fire test, which simulates the fire conditions which bare drums could be subjected to in storage. A theoretical model already exists in rough form which predicts wasteform temperature profiles and steam release rates from immobilized waste, the results from this programme of work will enable the modellers at Harwell to develop and validate this model and consequently predict both the gaseous and particulate, transport and release mechanisms from the waste matrix which may be encountered in fire accident conditions. This programme is being conducted in parallel and in close liaison with small-scale fully active studies at AERE Harwell under the CEC contract. 45 figs.; 5 tabs

  12. Surface fire intensity influences simulated crown fire behavior in lodgepole pine forests with recent mountain pine beetle-caused tree mortality

    Science.gov (United States)

    Chad M. Hoffman; Penelope Morgan; William Mell; Russell Parsons; Eva Strand; Steve. Cook

    2013-01-01

    Recent bark beetle outbreaks have had a significant impact on forests throughout western North America and have generated concerns about interactions and feedbacks between beetle attacks and fire. However, research has been hindered by a lack of experimental studies and the use of fire behavior models incapable of accounting for the heterogeneous fuel complexes. We...

  13. Fire Hazard Analysis for the Cold Vacuum Drying facility (CVD) Facility

    CERN Document Server

    Singh, G

    2000-01-01

    The CVDF is a nonreactor nuclear facility that will process the Spent Nuclear Fuels (SNF) presently stored in the 105-KE and 105-KW SNF storage basins. Multi-canister overpacks (MCOs) will be loaded (filled) with K Basin fuel transported to the CVDF. The MCOs will be processed at the CVDF to remove free water from the fuel cells (packages). Following processing at the CVDF, the MCOs will be transported to the CSB for interim storage until a long-term storage solution can be implemented. This operation is expected to start in November 2000. A Fire Hazard Analysis (FHA) is required for all new facilities and all nonreactor nuclear facilities, in accordance with U.S. Department of Energy (DOE) Order 5480.7A, Fire Protection. This FHA has been prepared in accordance with DOE 5480.7A and HNF-PRO-350, Fire Hazard Analysis Requirements. Additionally, requirements or criteria contained in DOE, Richland Operations Office (RL) RL Implementing Directive (RLID) 5480.7, Fire Protection, or other DOE documentation are cite...

  14. Combining spectral mixture analysis and object-based classification for fire severity mapping

    Energy Technology Data Exchange (ETDEWEB)

    Fernadez-Manso, O.; Quintano, C.; Quintano, C.; Fernandez-Manso, A.

    2009-07-01

    This study shows an accurate and fast methodology in order to evaluate fire severity classes of large forest fires. A single Landsat Enhanced Thematic Mapper multispectral image was utilized with the aim of mapping fire severity classes (high, moderate and low) using a combined-approach based in a spectral mixing model and object-based image analysis. A large wildfire in the Northwest of Spain was used to test the model. Fraction images obtained by Landsat unmixing were used as input data in the object-based image analysis. A multilevel segmentation and a classification were carried out by using membership functions. This method was compared with other simpler in order to evaluate the suitability to distinguish between the three fire severity classes above mentioned. McNemar's test was used to evaluate the statistical significance of the difference between approaches tested in this study. The combined approach achieved the highest accuracy reaching 97.32% and kappa index of agreement of 95.96% and improving accuracy of individual classes. (Author) 89 refs.

  15. Class-conditional feature modeling for ignitable liquid classification with substantial substrate contribution in fire debris analysis

    NARCIS (Netherlands)

    Lopatka, M.; Sigman, M.E.; Sjerps, M.J.; Williams, M.R.; Vivó-Truyols, G.

    2015-01-01

    Forensic chemical analysis of fire debris addresses the question of whether ignitable liquid residue is present in a sample and, if so, what type. Evidence evaluation regarding this question is complicated by interference from pyrolysis products of the substrate materials present in a fire. A method

  16. Afforestation, subsequent forest fires and provision of hydrological services: a model-based analysis for a Mediterranean mountainous catchment

    Science.gov (United States)

    Nunes, João Pedro; Naranjo Quintanilla, Paula; Santos, Juliana; Serpa, Dalila; Carvalho-Santos, Cláudia; Rocha, João; Keizer, Jan Jacob; Keesstra, Saskia

    2017-04-01

    Mediterranean landscapes have experienced extensive abandonment and reforestation in recent decades, which should have improved the provision of hydrological services, such as flood mitigation, soil erosion protection and water quality regulation. However, these forests are fire-prone, and the post-fire increase in runoff, erosion and sediment exports could negatively affect service provision. This issue was assessed using the SWAT model for a small mountain agroforestry catchment, which was monitored between 2010 and 2014 and where some eucalypt stands burned in 2011 and were subsequently plowed for replanting. The model was calibrated and validated for streamflow, sediment yield and erosion in agricultural fields and the burnt hillslopes, showing that it can be adapted for post-fire simulation. It was then used to perform a decadal assessment of surface runoff, erosion, and sediment exports between 2004 and 2014. Results show that the fire did not noticeably affect flood mitigation but that it increased erosion by 3 orders of magnitude, which subsequently increased sediment yield. Erosion in the burnt forest during this decade was one order of magnitude above that in agricultural fields. SWAT was also used to assess different fire and land-use scenarios during the same period. Results indicate that the impacts of fire were lower without post-fire soil management, and when the fire occurred in pine forests (i.e. before the 1990s) or in shrublands (i.e. before afforestation in the 1930s). These impacts were robust to changes in post-fire weather conditions and to a lower fire frequency (20-year intervals). The results suggest that, in the long term, fire-prone forests might not provide the anticipated soil protection and water quality regulation services in wet Mediterranean regions.

  17. Atmosphere-fire simulation of effects of low-level jets on pyro-convective plume dynamics

    Science.gov (United States)

    Colin C. Simpson; Marwan Katurji; Michael T. Kiefer; Shiyuan Zhong; Joseph J. Charney; Warren E. Heilman; Xindi. Bian

    2013-01-01

    Blow-up fire behaviour can be broadly defined as a rapid escalation in the intensity or forward rate of spread of a wildland fire, and is often accompanied by extreme pyro-convection associated with rapid smoke release and dispersion. Blow-up fire behaviour is difficult to predict and has been linked to firefighter fatalities, making it an important fire management...

  18. Simulation data analysis by virtual reality system

    International Nuclear Information System (INIS)

    Ohtani, Hiroaki; Mizuguchi, Naoki; Shoji, Mamoru; Ishiguro, Seiji; Ohno, Nobuaki

    2010-01-01

    We introduce new software for analysis of time-varying simulation data and new approach for contribution of simulation to experiment by virtual reality (VR) technology. In the new software, the objects of time-varying field are visualized in VR space and the particle trajectories in the time-varying electromagnetic field are also traced. In the new approach, both simulation results and experimental device data are simultaneously visualized in VR space. These developments enhance the study of the phenomena in plasma physics and fusion plasmas. (author)

  19. Stochastic simulation algorithms and analysis

    CERN Document Server

    Asmussen, Soren

    2007-01-01

    Sampling-based computational methods have become a fundamental part of the numerical toolset of practitioners and researchers across an enormous number of different applied domains and academic disciplines. This book provides a broad treatment of such sampling-based methods, as well as accompanying mathematical analysis of the convergence properties of the methods discussed. The reach of the ideas is illustrated by discussing a wide range of applications and the models that have found wide usage. The first half of the book focuses on general methods, whereas the second half discusses model-specific algorithms. Given the wide range of examples, exercises and applications students, practitioners and researchers in probability, statistics, operations research, economics, finance, engineering as well as biology and chemistry and physics will find the book of value.

  20. SYSTEMS SAFETY ANALYSIS FOR FIRE EVENTS ASSOCIATED WITH THE ECRB CROSS DRIFT

    International Nuclear Information System (INIS)

    R. J. Garrett

    2001-01-01

    The purpose of this analysis is to systematically identify and evaluate fire hazards related to the Yucca Mountain Site Characterization Project (YMP) Enhanced Characterization of the Repository Block (ECRB) East-West Cross Drift (commonly referred to as the ECRB Cross-Drift). This analysis builds upon prior Exploratory Studies Facility (ESF) System Safety Analyses and incorporates Topopah Springs (TS) Main Drift fire scenarios and ECRB Cross-Drift fire scenarios. Accident scenarios involving the fires in the Main Drift and the ECRB Cross-Drift were previously evaluated in ''Topopah Springs Main Drift System Safety Analysis'' (CRWMS M and O 1995) and the ''Yucca Mountain Site Characterization Project East-West Drift System Safety Analysis'' (CRWMS M and O 1998). In addition to listing required mitigation/control features, this analysis identifies the potential need for procedures and training as part of defense-in-depth mitigation/control features. The inclusion of this information in the System Safety Analysis (SSA) is intended to assist the organization(s) (e.g., Construction, Environmental Safety and Health, Design) responsible for these aspects of the ECRB Cross-Drift in developing mitigation/control features for fire events, including Emergency Refuge Station(s). This SSA was prepared, in part, in response to Condition/Issue Identification and Reporting/Resolution System (CIRS) item 1966. The SSA is an integral part of the systems engineering process, whereby safety is considered during planning, design, testing, and construction. A largely qualitative approach is used which incorporates operating experiences and recommendations from vendors, the constructor and the operating contractor. The risk assessment in this analysis characterizes the scenarios associated with fires in terms of relative risk and includes recommendations for mitigating all identified hazards. The priority for recommending and implementing mitigation control features is: (1) Incorporate

  1. Exergy Analysis of Operating Lignite Fired Thermal Power Plant

    OpenAIRE

    K. Murugesan; R. P. Gakkhar; N. Alagumurthi; T. Ganapathy

    2009-01-01

    The energy assessment must be made through the energy quantity as well as the quality. But the usual energy analysisevaluates the energy generally on its quantity only. However, the exergy analysis assesses the energy on quantity as well asthe quality. The aim of the exergy analysis is to identify the magnitudes and the locations of real energy losses, in order toimprove the existing systems, processes or components. The present paper deals with an exergy analysis performed on anoperating 50M...

  2. Failure analysis of fire resistant fluid (FRF piping used in hydraulic control system at oil-fired thermal power generation plant

    Directory of Open Access Journals (Sweden)

    Muhammad Akram

    2017-04-01

    Full Text Available This is a case study regarding frequent forced outages in an oil-fired power generating station due to failure of fire resistant fluid (FRF piping of material ASTM A-304. This analysis was done to find out the most probable cause of failure and to rectify the problem. Methods for finding and analyzing the cracks include nondestructive testing techniques such as visual testing (VT and dye penetrant testing (PT along with that periodic monitoring after rectification of problem. The study revealed that pitting and pit to crack transitions were formed in stainless steel piping containing high pressure (system pressure 115 bars fire resistant fluid. However, after replacement of piping the pitting and cracking reoccurred. It was observed that due to possible exposure to chlorinated moisture in surrounding environment pitting was formed which then transformed into cracks. The research work discussed in this paper illustrates the procedure used in detection of the problem and measures taken to solve the problem.

  3. Detection, Emission Estimation and Risk Prediction of Forest Fires in China Using Satellite Sensors and Simulation Models in the Past Three Decades—An Overview

    Directory of Open Access Journals (Sweden)

    Cheng Liu

    2011-07-01

    Full Text Available Forest fires have major impact on ecosystems and greatly impact the amount of greenhouse gases and aerosols in the atmosphere. This paper presents an overview in the forest fire detection, emission estimation, and fire risk prediction in China using satellite imagery, climate data, and various simulation models over the past three decades. Since the 1980s, remotely-sensed data acquired by many satellites, such as NOAA/AVHRR, FY-series, MODIS, CBERS, and ENVISAT, have been widely utilized for detecting forest fire hot spots and burned areas in China. Some developed algorithms have been utilized for detecting the forest fire hot spots at a sub-pixel level. With respect to modeling the forest burning emission, a remote sensing data-driven Net Primary productivity (NPP estimation model was developed for estimating forest biomass and fuel. In order to improve the forest fire risk modeling in China, real-time meteorological data, such as surface temperature, relative humidity, wind speed and direction,have been used as the model input for improving prediction of forest fire occurrence and its behavior. Shortwave infrared (SWIR and near infrared (NIR channels of satellite sensors have been employed for detecting live fuel moisture content (FMC, and the Normalized Difference Water Index (NDWI was used for evaluating the forest vegetation condition and its moisture status.

  4. Detection, emission estimation and risk prediction of forest fires in China using satellite sensors and simulation models in the past three decades--an overview.

    Science.gov (United States)

    Zhang, Jia-Hua; Yao, Feng-Mei; Liu, Cheng; Yang, Li-Min; Boken, Vijendra K

    2011-08-01

    Forest fires have major impact on ecosystems and greatly impact the amount of greenhouse gases and aerosols in the atmosphere. This paper presents an overview in the forest fire detection, emission estimation, and fire risk prediction in China using satellite imagery, climate data, and various simulation models over the past three decades. Since the 1980s, remotely-sensed data acquired by many satellites, such as NOAA/AVHRR, FY-series, MODIS, CBERS, and ENVISAT, have been widely utilized for detecting forest fire hot spots and burned areas in China. Some developed algorithms have been utilized for detecting the forest fire hot spots at a sub-pixel level. With respect to modeling the forest burning emission, a remote sensing data-driven Net Primary productivity (NPP) estimation model was developed for estimating forest biomass and fuel. In order to improve the forest fire risk modeling in China, real-time meteorological data, such as surface temperature, relative humidity, wind speed and direction, have been used as the model input for improving prediction of forest fire occurrence and its behavior. Shortwave infrared (SWIR) and near infrared (NIR) channels of satellite sensors have been employed for detecting live fuel moisture content (FMC), and the Normalized Difference Water Index (NDWI) was used for evaluating the forest vegetation condition and its moisture status.

  5. Multi-temporal analysis of forest fire risk driven by environmental and socio-economic change in the Republic of Korea

    Science.gov (United States)

    Kim, S. J.; Lim, C. H.; Kim, G. S.; Lee, W. K.

    2017-12-01

    Analysis of forest fire risk is important in disaster risk reduction (DRR) since it provides a way to manage forest fires. Climate and socio-economic factors are important in the cause of forest fires, and the role of the socio-economic factors in prevention and preparedness of forest fires is increasing. As most of the forest fires in the Republic of Korea are highly related to human activities, both environmental factors and socio-economic factors were considered into the analysis of forest fire risk. In this study, the Maximum Entropy (MaxEnt) model was used to predict the potential geographical distribution and probability of forest fire occurrence spatially and temporally from 1980s to the 2010s in the Republic of Korea by multi-temporal analysis and analyze the relationship between forest fires and the factors. As a result of the risk analysis, there was an overall increasing trend in forest fire risk from the 1980s to the 2000s, and socio-economic factors were highly correlated with the occurrence of forest fires. The study demonstrates that the socio-economic factors considered as human activities can increase the occurrence of forest fires. The result implies that managing human activities are significant to prevent forest fire occurrence. In addition, timely forest fire prevention and control is necessary as drought index such as Standardized Precipitation Index (SPI) also affected forest fires.

  6. Cofiring of biofuels in coal fired boilers: Results of case study analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tillman, D.A. [Ebasco Environmental, Sacramento, CA (United States); Hughes, E. [Electric Power Research Institute, Palo Alto, CA (United States); Gold, B.A. [TVA, Chattanooga, TN (United States)

    1993-12-31

    Ebasco Environmental and Reaction Engineering, under contract to EPRI, performed a case study analysis of cofiring biomass in coal-fired boilers of the Tennessee Valley Authority (TVA). The study was also sponsored by DOE. This analysis included evaluating wood fuel receiving, preparation, and combustion in pulverized coal (PC) boilers and cyclone furnaces and an assessment of converting wood into pyrolysis oil or low Btu gas for use in a new combined cycle combustion turbine (CCCT) installation. Cofiring wood in existing coal-fired boilers has the most immediate potential for increasing the utilization of biofuels in electricity generation. Cofiring biofuels with coal can potentially generate significant benefits for utilities including: (1) reducing emissions of SO{sub 2} and NO{sub x}; (2) reducing the net emissions of CO{sub 2}; (3) potentially reducing the fuel cost to the utility depending upon local conditions and considering biomass is potentially exempt from the proposed Btu tax and may get a 1.5 cent/kWh credit for energy generated by wood combustion; (4) supporting local industrial forest industry; and (5) providing a long term market for the development of a biofuel supply and delivery industry. Potential benefits are reviewed in the context of cofiring biofuel at a rate of 15% heat input to the boiler, and compares this cofiring strategy and others previously tested or developed by other utilities. Other issues discussed include: (1) wood fuel specifications as a function of firing method; (2) wood fuel receiving and preparation system requirements; (3) combustion system requirements for cofiring biofuels with coal; (4) combustion impacts of firing biofuels with coal; (5) system engineering issues; (6) the economics of cofiring biofuel with coal. The Allen, TN 330 MW(e) cyclone boiler and Kingston, TN 135 MW(e) Boiler {number_sign}1, a tangentially fired PC unit, case studies are then summarized in the paper, highlighting the cofiring opportunities.

  7. Modeling and numerical analysis of granite rock specimen under mechanical loading and fire

    Directory of Open Access Journals (Sweden)

    Luc Leroy Ngueyep. Mambou

    2015-02-01

    Full Text Available The effect of ISO 834 fire on the mechanical properties of granite rock specimen submitted to uniaxial loading is numerically investigated. Based on Newton's second law, the rate-equation model of granite rock specimen under mechanical load and fire is established. The effect of heat treatment on the mechanical performance of granite is analyzed at the center and the ends of specimen. At the free end of granite rock specimen, it is shown that from 20 °C to 500 °C, the internal stress and internal strain are weak; whereas above 500 °C, they start to increase rapidly, announcing the imminent collapse. At the center of specimen, the analysis of the internal stress and internal strain reveals that the fire reduces the mechanical performance of granite significantly. Moreover, it is found that after 3 min of exposure to fire, the mechanical energy necessary to fragment the granite can be reduced up to 80%.

  8. Numerical Analysis of Heat Transfer in Fire-Protective Coatings Deformable upon Heating

    Science.gov (United States)

    Rudzinsky, V. P.; Garashchenko, A. N.

    2016-02-01

    Numerical studies of heat transfer in fire-protective coatings deformable (intumescent) upon heating have been conducted. The optimum combination of the computation-scheme parameters providing stability, convergence and satisfactory accuracy of solutions has been determined. An effect of basic characteristics of materials in real range of their change that made it possible to estimate the degree of influence of properties on the fire-protective efficiency of coatings and the level of warm-up (flame resistance) of structures to be protected with them has been studied. The possibility of using developed models and techniques to estimate and provide the required level of fire safety of polymer-based materials (in particular, elastomers and structures and products on their basis) is considered. The results of estimating the mass rate of evolving gaseous thermal-decomposition products that determine, in a considerable extent, the material combustibility have been presented. The numerical analysis results have demonstrated the potentiality of reducing the combustibility of such materials and increasing limits of their fire resistance at the expense of organizing the intumescence of a material upon heating by means of modification of their initial formulations as well as with the aid of an additional layer made of the intumescent coating compatible with an elastomer.

  9. Risk-informed decision-making analysis for the electrical raceway fire barrier systems on a BWR-4 plant

    International Nuclear Information System (INIS)

    Wu, Ching-Hui; Lin, Tsu-Jen; Kao, Tsu-Mu; Chen, Chyn-Rong

    2003-01-01

    This paper describes a risk-informed decision-making approach used to resolve the fire barrier issue in a BWR-4 nuclear plant where Appendix R separation requirements cannot be met without installing additional fire protection features such as electrical raceway fire barrier system. The related risk measures in CDF (core damage frequency) and LERF (large early release frequency) of the fire barrier issue can be determined by calculating the difference in plant risks between various alternative cases and that met the requirement of the Appendix R. In some alternative cases, additional early-detection and fast-response fire suppression systems are suggested. In some other cases, cable re-routing of some improper layout of non-safety related cables are required. Sets of fire scenarios are re-evaluated more detailed by reviewing the cable damage impact for the BWR-4 plant. The fire hazard model, COMPBRM III-e, is used in this study and the dominant results in risk measures are benchmarked with the CFD code, FDS 2.0, to ensure that the risk impact of fire barrier is estimated accurately in the risk-informed decision making. The traditional deterministic qualitative methods, such as defense-in-depth, safety margin and post-fire safety shutdown capability are also proceeded. The value-impact analysis for proposed alternatives of fire wrapping required by Appendix R has been completed for technical basis of the exemption on Appendix R application. The outcome of the above analysis should be in compliance with the regulatory guidelines (RG) 1.174 and 1.189 for the applications in the risk-informed decision-making of the fire wrapping issues. (author)

  10. Analysis of residual swirl in tangentially-fired natural gas-boiler

    International Nuclear Information System (INIS)

    Hasril Hasini; Muhammad Azlan Muad; Mohd Zamri Yusoff; Norshah Hafeez Shuaib

    2010-01-01

    This paper describes the investigation on residual swirl flow in a 120 MW natural gas, full-scale, tangential-fired boiler. Emphasis is given towards the understanding of the behavior of the combustion gas flow pattern and temperature distribution as a result of the tangential firing system of the boiler. The analysis was carried out based on three-dimensional computational modeling on full scale boiler with validation from key design parameter as well as practical observation. Actual operating parameters of the actual boiler are taken as the boundary conditions for this modeling. The prediction of total heat flux was found to be in agreement with the key design parameter while the residual swirl predicted at the upper furnace agrees qualitatively with the practical observation. Based on this comparison, detail analysis was carried out for comprehensive understanding on the generation and destruction of the residual swirl behavior in boiler especially those with high capacity. (author)

  11. Three-dimensional rail cooling analysis for a repetitively fired railgun

    International Nuclear Information System (INIS)

    Liu, H.P.

    1991-01-01

    This paper reports on a three-dimensional (3-D) rail cooling analysis for fabrication and demonstration of a stand-alone repetitive fire compulsator driven 9 MJ gun system which has been performed to assure the entire rail can be maintained below its thermal limit for multiple shots. The 3-D rail thermal model can predict the temperature, pressure, and convective heat transfer coefficient variations of the coolant along the 10 m long copper rail. The 9-MJ projectiles will be fired every 20 s for 3 min. Water cooling was used in the model for its high cooling capacity. Single liquid phase heat transfer was assumed in the cooling analysis. For multiple shots, the temperature difference between the rail and the water was enhanced due to accumulated heat in the rail. As a result, the heat removal by water increased from shot-to-shot. The rail temperature initially increased and finally stabilized after a number of shots

  12. Cloud properties from the analysis of AVHRR observations for FIRE 2

    Science.gov (United States)

    Lin, Xijian; Coakley, James A., Jr.

    1993-01-01

    Preliminary results are presented for cloud properties from the analysis of AVHRR observations for FIRE 2. The properties were obtained from a combination of the spatial coherence method and a multispectral retrieval scheme. Geographically gritted fields for the number of cloud layers were produced. For single layered cloud systems, fractional cloud cover, cloud emission temperature, cloud emissivity, and particle size were retrieved. Statistics on the properties of upper-level clouds and the Coffeeville cloud conditions are presented.

  13. Experimental analysis of a combustion reactor under co-firing coal with biomass

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Fabyo Luiz; Bazzo, Edson; Oliveira Junior, Amir Antonio Martins de [Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil). LabCET], e-mail: ebazzo@emc.ufsc.br; Bzuneck, Marcelo [Tractebel Energia S.A., Complexo Termeletrico Jorge Lacerda, Capivari de Baixo, SC (Brazil)], e-mail: marcelob@tractebelenergia.com.br

    2010-07-01

    Mitigation of greenhouse gases emission is one of the most important issues in energy engineering. Biomass is a potential renewable source but with limited use in large scale energy production because of the relative smaller availability as compared to fossil fuels, mainly to coal. Besides, the costs concerning transportation must be well analysed to determine its economic viability. An alternative for the use of biomass as a primary source of energy is the co-firing, that is the possibility of using two or more types of fuels combined in the combustion process. Biomass can be co-fired with coal in a fraction between 10 to 25% in mass basis (or 4 to 10% in heat-input basis) without seriously impacting the heat release characteristics of most boilers. Another advantage of cofiring, besides the significant reductions in fossil CO{sub 2} emissions, is the reduced emissions of NO{sub x} and SO{sub x}. As a result, co-firing is becoming attractive for power companies worldwide. This paper presents results of some experimental analysis on co-firing coal with rice straw in a combustion reactor. The influence of biomass thermal share in ash composition is also discussed, showing that alkali and earth alkaline compounds play the most important role on the fouling and slagging behavior when co-firing. Some fusibility correlations that can assist in the elucidation of these behavior are presented and discussed, and then applied to the present study. Results show that for a biomass thermal share up to 20%, significant changes are not expected in fouling and slagging behavior of ash. (author)

  14. Sequentially linear analysis for simulating brittle failure

    NARCIS (Netherlands)

    van de Graaf, A.V.

    2017-01-01

    The numerical simulation of brittle failure at structural level with nonlinear finite
    element analysis (NLFEA) remains a challenge due to robustness issues. We attribute these problems to the dimensions of real-world structures combined with softening behavior and negative tangent stiffness at

  15. Reliability Analysis Of Fire System On The Industry Facility By Use Fameca Method

    International Nuclear Information System (INIS)

    Sony T, D.T.; Situmorang, Johnny; Ismu W, Puradwi; Demon H; Mulyanto, Dwijo; Kusmono, Slamet; Santa, Sigit Asmara

    2000-01-01

    FAMECA is one of the analysis method to determine system reliability on the industry facility. Analysis is done by some procedure that is identification of component function, determination of failure mode, severity level and effect of their failure. Reliability value is determined by three combinations that is severity level, component failure value and critical component. Reliability of analysis has been done for fire system on the industry by FAMECA method. Critical component which identified is pump, air release valve, check valve, manual test valve, isolation valve, control system etc

  16. Numerical simulation of nucleation scavenging within smoke plumes above large fires

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, M.M.

    1986-12-01

    This paper presents preliminary results from an on-going smoke plume research project. The goal is to determine reasonable estimates of vertical distribution of smoke in the early post-nuclear-exchange environment, accounting for the air circulations forced by large, intense fires and for the possible prompt removal of smoke due to various scavenging mechanisms within pyrogenic clouds. These estimates may facilitate improved global-scale calculations by providing more accurate initial smoke distributions than have previously been available. Early results suggest that scavenging of smoke particles due to their activation as condensation nuclei may significantly reduce the amount of smoke available for climate modification. It appears that this scavenging process operates most efficiently in the smoke plumes which rise to the highest altitudes. Even if overseeding inhibits cloud droplet coalescence, rain may still form due to the collection of cloud droplets by very large aerosol particles.

  17. Cinema Fire Modelling by FDS

    International Nuclear Information System (INIS)

    Glasa, J; Valasek, L; Weisenpacher, P; Halada, L

    2013-01-01

    Recent advances in computer fluid dynamics (CFD) and rapid increase of computational power of current computers have led to the development of CFD models capable to describe fire in complex geometries incorporating a wide variety of physical phenomena related to fire. In this paper, we demonstrate the use of Fire Dynamics Simulator (FDS) for cinema fire modelling. FDS is an advanced CFD system intended for simulation of the fire and smoke spread and prediction of thermal flows, toxic substances concentrations and other relevant parameters of fire. The course of fire in a cinema hall is described focusing on related safety risks. Fire properties of flammable materials used in the simulation were determined by laboratory measurements and validated by fire tests and computer simulations

  18. Chapter 3: Simulating fire hazard across landscapes through time: integrating state-and-transition models with the Fuel Characteristic Classification System

    Science.gov (United States)

    Jessica E. Halofsky; Stephanie K. Hart; Miles A. Hemstrom; Joshua S. Halofsky; Morris C. Johnson

    2014-01-01

    Information on the effects of management activities such as fuel reduction treatments and of processes such as vegetation growth and disturbance on fire hazard can help land managers prioritize treatments across a landscape to best meet management goals. State-and-transition models (STMs) allow landscape-scale simulations that incorporate effects of succession,...

  19. Simulated response of conterminous United States ecosystems to climate change at different levels of fire suppression, CO2 emission rate, and growth response to CO2

    Science.gov (United States)

    James M. Lenihan; Dominique Bachelet; Ronald P. Neilson; Raymond Drapek

    2008-01-01

    A modeling experiment was designed to investigate the impact of fire management, CO2 emission rate, and the growth response to CO2 on the response of ecosystems in the conterminous United States to climate scenarios produced by three different general circulation models (GCMs) as simulated by the MCl Dynamic General...

  20. A comparison of three approaches for simulating fine-scale surface winds in support of wildland fire management: Part I. Model formulation and comparison against measurements

    Science.gov (United States)

    Jason M. Forthofer; Bret W. Butler; Natalie S. Wagenbrenner

    2014-01-01

    For this study three types of wind models have been defined for simulating surface wind flow in support of wildland fire management: (1) a uniform wind field (typically acquired from coarse-resolution (,4 km) weather service forecast models); (2) a newly developed mass-conserving model and (3) a newly developed mass and momentumconserving model (referred to as the...

  1. Quantitative Image Simulation and Analysis of Nanoparticles

    DEFF Research Database (Denmark)

    Madsen, Jacob; Hansen, Thomas Willum

    Microscopy (HRTEM) has become a routine analysis tool for structural characterization at atomic resolution, and with the recent development of in-situ TEMs, it is now possible to study catalytic nanoparticles under reaction conditions. However, the connection between an experimental image, and the underlying...... of strain measurements from TEM images, and investigate the stability of these measurements to microscope parameters. This is followed by our efforts toward simulating metal nanoparticles on a metal-oxide support using the Charge Optimized Many Body (COMB) interatomic potential. The simulated interface...

  2. Analysis of the influence of operating conditions on fouling rates in fired heaters

    International Nuclear Information System (INIS)

    Morales-Fuentes, A.; Picón-Núñez, M.; Polley, G.T.; Méndez-Díaz, S.

    2014-01-01

    Fouling due to chemical reaction in preheat trains for the processing of crude oil plays a key role in the operation and maintenance costs and on greenhouse emissions to atmosphere in crude processing plants. A preheat train consists of a set of heat transfer units that provide the crude oil stream the required amount of thermal energy to reach its target temperature either by heat recovery or by direct firing. Fired heaters supply external high temperature heating through the burning of fuel which result in complex heat transfer processes due to the large temperature and pressure changes and vaporization that takes place inside the unit. In this work, a thermo-hydraulic analysis of the performance of fired heaters is carried out through the application of commercial software to solve the mathematical models using finite difference methods; the analysis is applied to the crude side of a vertical fired heater in order to evaluate the impact of process conditions such as throughput and crude inlet temperature (CIT) on the fouling that take place at the early stages of operation. Using a fouling rate model based on thermo-hydraulic parameters, fouling rates are predicted assuming steady state operation and clean conditions. Although variations in process conditions are known to influence fouling rates, little work has been done on the subject. In this work excess air and steam injection are studied as a means to mitigate fouling. Results show that throughput reduction brings about a marked increase in the fouling rates. A decrease in CIT affects only the convection zone and it is found that this effect is negligible. In terms of excess air, it is found that although it affects negatively the heater efficiency it can be used to balance heat transfer between the convection and radiation zone in a way that fouling rates are reduced; however this strategy should be considered right from the design stage. Finally it is observed that steam injection is an effective method

  3. Identifying past fire regimes throughout the Holocene in Ireland using new and established methods of charcoal analysis

    Science.gov (United States)

    Hawthorne, Donna; Mitchell, Fraser J. G.

    2016-04-01

    Globally, in recent years there has been an increase in the scale, intensity and level of destruction caused by wildfires. This can be seen in Ireland where significant changes in vegetation, land use, agriculture and policy, have promoted an increase in fires in the Irish landscape. This study looks at wildfire throughout the Holocene and draws on lacustrine charcoal records from seven study sites spread across Ireland, to reconstruct the past fire regimes recorded at each site. This work utilises new and accepted methods of fire history reconstruction to provide a recommended analytical procedure for statistical charcoal analysis. Digital charcoal counting was used and fire regime reconstructions carried out via the CharAnalysis programme. To verify this record new techniques are employed; an Ensemble-Member strategy to remove the objectivity associated with parameter selection, a Signal to Noise Index to determine if the charcoal record is appropriate for peak detection, and a charcoal peak screening procedure to validate the identified fire events based on bootstrapped samples. This analysis represents the first study of its kind in Ireland, examining the past record of fire on a multi-site and paleoecological timescale, and will provide a baseline level of data which can be built on in the future when the frequency and intensity of fire is predicted to increase.

  4. Co-firing coal with wood pellets for U.S. electricity generation: A real options analysis

    International Nuclear Information System (INIS)

    Xian, Hui; Colson, Gregory; Mei, Bin; Wetzstein, Michael E.

    2015-01-01

    In contrast to EU, U.S. electric utilities are not employing the bioenergy technology of co-firing wood pellets with coal. This difference in employment patterns is explored within a real options analysis (ROA) for possible U.S. utilization of wood pellets, considering fuel-price series from 2009 to 2014. For analysis, these series are divided into two sub-periods based on different market conditions: Infancy (2009–2011) and Substitution (2012–2014). ROA indicates co-firing wood pellets with coal is feasible considering adoption during wood pellets' infancy, under low discount rates, and long power-plant lifespans. A portfolio effect of employing multiple fuels underlies this result. However, co-firing is not currently economically feasible. The different adoption decisions are likely a consequence of recent cheap and abundant U.S. natural gas. For co-fired wood pellets to be feasible, government incentives and/or a market increase in natural gas prices appear necessary. -- Highlights: •Real options analysis indicates co-firing is not currently economically feasible within the U.S. •The recent U.S. natural-gas boom is likely hindering the adoption of co-firing. •For co-fired adoption, government incentives or an increase in natural-gas prices are necessary

  5. Response Predicting LTCC Firing Shrinkage: A Response Surface Analysis Study

    Energy Technology Data Exchange (ETDEWEB)

    Girardi, Michael; Barner, Gregg; Lopez, Cristie; Duncan, Brent; Zawicki, Larry

    2009-02-25

    The Low Temperature Cofired Ceramic (LTCC) technology is used in a variety of applications including military/space electronics, wireless communication, MEMS, medical and automotive electronics. The use of LTCC is growing due to the low cost of investment, short development time, good electrical and mechanical properties, high reliability, and flexibility in design integration (3 dimensional (3D) microstructures with cavities are possible)). The dimensional accuracy of the resulting x/y shrinkage of LTCC substrates is responsible for component assembly problems with the tolerance effect that increases in relation to the substrate size. Response Surface Analysis was used to predict product shrinkage based on specific process inputs (metal loading, layer count, lamination pressure, and tape thickness) with the ultimate goal to optimize manufacturing outputs (NC files, stencils, and screens) in achieving the final product design the first time. Three (3) regression models were developed for the DuPont 951 tape system with DuPont 5734 gold metallization based on green tape thickness.

  6. Firing the furnace? An econometric analysis of utilities' fuel choice

    International Nuclear Information System (INIS)

    Tauchmann, H.

    2006-01-01

    This paper attempts to estimate how the fuel mix of German electricity producers does react to fuel price changes. The empirical analysis is based on panel data (1968-1998) of major utilities. Two different aspects of fuel choice are distinguished: at the one hand, the construction of usually fuel-specific capacities for electric power generation, i.e. investment decisions that determine the fuel mix in the long run; at the other, fuel use conditional on existing generation capacities, i.e. short-run inter-fuel substitution. According to the results from panel unit root tests, both the econometric models which describe these two aspects are specified in changes rather than levels. The partly discrete nature of investment decisions is taken into account, by constructing a discrete model of capacity adjustment. Our estimation results suggest that the fuel mix of electric utilities is price inelastic either if long-term investment or short-term inter-fuel substitution is considered. Finally, the empirical results are used to predict the potential impacts of CO 2 emissions trading on fuel choice in the German electric power industry. (Author)

  7. The effectiveness and limitations of fuel modeling using the fire and fuels extension to the Forest Vegetation Simulator

    Science.gov (United States)

    Erin K. Noonan-Wright; Nicole M. Vaillant; Alicia L. Reiner

    2014-01-01

    Fuel treatment effectiveness is often evaluated with fire behavior modeling systems that use fuel models to generate fire behavior outputs. How surface fuels are assigned, either using one of the 53 stylized fuel models or developing custom fuel models, can affect predicted fire behavior. We collected surface and canopy fuels data before and 1, 2, 5, and 8 years after...

  8. Assessing Wildfire Risk in Cultural Heritage Properties Using High Spatial and Temporal Resolution Satellite Imagery and Spatially Explicit Fire Simulations: The Case of Holy Mount Athos, Greece

    Directory of Open Access Journals (Sweden)

    Giorgos Mallinis

    2016-02-01

    Full Text Available Fire management implications and the design of conservation strategies on fire prone landscapes within the UNESCO World Heritage Properties require the application of wildfire risk assessment at landscape level. The objective of this study was to analyze the spatial variation of wildfire risk on Holy Mount Athos in Greece. Mt. Athos includes 20 monasteries and other structures that are threatened by increasing frequency of wildfires. Site-specific fuel models were created by measuring in the field several fuel parameters in representative natural fuel complexes, while the spatial extent of the fuel types was determined using a synergy of high-resolution imagery and high temporal information from medium spatial resolution imagery classified through object-based analysis and a machine learning classifier. The Minimum Travel Time (MTT algorithm, as it is embedded in FlamMap software, was applied in order to evaluate Burn Probability (BP, Conditional Flame Length (CFL, Fire Size (FS, and Source-Sink Ratio (SSR. The results revealed low burn probabilities for the monasteries; however, nine out of the 20 monasteries have high fire potential in terms of fire intensity, which means that if an ignition occurs, an intense fire is expected. The outputs of this study may be used for decision-making for short-term predictions of wildfire risk at an operational level, contributing to fire suppression and management of UNESCO World Heritage Properties.

  9. Stochastic analysis for finance with simulations

    CERN Document Server

    Choe, Geon Ho

    2016-01-01

    This book is an introduction to stochastic analysis and quantitative finance; it includes both theoretical and computational methods. Topics covered are stochastic calculus, option pricing, optimal portfolio investment, and interest rate models. Also included are simulations of stochastic phenomena, numerical solutions of the Black–Scholes–Merton equation, Monte Carlo methods, and time series. Basic measure theory is used as a tool to describe probabilistic phenomena. The level of familiarity with computer programming is kept to a minimum. To make the book accessible to a wider audience, some background mathematical facts are included in the first part of the book and also in the appendices. This work attempts to bridge the gap between mathematics and finance by using diagrams, graphs and simulations in addition to rigorous theoretical exposition. Simulations are not only used as the computational method in quantitative finance, but they can also facilitate an intuitive and deeper understanding of theoret...

  10. Subset simulation for structural reliability sensitivity analysis

    International Nuclear Information System (INIS)

    Song Shufang; Lu Zhenzhou; Qiao Hongwei

    2009-01-01

    Based on two procedures for efficiently generating conditional samples, i.e. Markov chain Monte Carlo (MCMC) simulation and importance sampling (IS), two reliability sensitivity (RS) algorithms are presented. On the basis of reliability analysis of Subset simulation (Subsim), the RS of the failure probability with respect to the distribution parameter of the basic variable is transformed as a set of RS of conditional failure probabilities with respect to the distribution parameter of the basic variable. By use of the conditional samples generated by MCMC simulation and IS, procedures are established to estimate the RS of the conditional failure probabilities. The formulae of the RS estimator, its variance and its coefficient of variation are derived in detail. The results of the illustrations show high efficiency and high precision of the presented algorithms, and it is suitable for highly nonlinear limit state equation and structural system with single and multiple failure modes

  11. Advanced numerical modelling of a fire. Final report

    International Nuclear Information System (INIS)

    Heikkilae, L.; Keski-Rahkonen, O.

    1996-03-01

    Experience and probabilistic risk assessments show that fires present a major hazard in a nuclear power plant (NPP). The PALOME project (1988-92) improved the quality of numerical simulation of fires to make it a useful tool for fire safety analysis. Some of the most advanced zone model fire simulation codes were acquired. The performance of the codes was studied through literature and personal interviews in earlier studies and BRI2 code from the Japanese Building Research Institute was selected for further use. In PALOME 2 project this work was continued. Information obtained from large-scale fire tests at the German HDR facility allowed reliable prediction of the rate of heat release and was used for code validation. BRI2 code was validated particularly by participation in the CEC standard problem 'Prediction of effects caused by a cable fire experiment within the HDR-facility'. Participation in the development of a new field model code SOFIE specifically for fire applications as British-Swedish-Finnish cooperation was one of the goals of the project. SOFIE code was implemented at VTT and the first results of validation simulations were obtained. Well instrumented fire tests on electronic cabinets were carried out to determine source terms for simulation of room fires and to estimate fire spread to adjacent cabinets. The particular aim of this study was to measure the rate of heat release from a fire in an electronic cabinet. From the three tests, differing mainly in the amount of the fire load, data was obtained for source terms in numerical modelling of fires in rooms containing electronic cabinets. On the basis of these tests also a simple natural ventilation model was derived. (19 refs.)

  12. Techniques in micromagnetic simulation and analysis

    Science.gov (United States)

    Kumar, D.; Adeyeye, A. O.

    2017-08-01

    Advances in nanofabrication now allow us to manipulate magnetic material at micro- and nanoscales. As the steps of design, modelling and simulation typically precede that of fabrication, these improvements have also granted a significant boost to the methods of micromagnetic simulations (MSs) and analyses. The increased availability of massive computational resources has been another major contributing factor. Magnetization dynamics at micro- and nanoscale is described by the Landau-Lifshitz-Gilbert (LLG) equation, which is an ordinary differential equation (ODE) in time. Several finite difference method (FDM) and finite element method (FEM) based LLG solvers are now widely use to solve different kind of micromagnetic problems. In this review, we present a few patterns in the ways MSs are being used in the pursuit of new physics. An important objective of this review is to allow one to make a well informed decision on the details of simulation and analysis procedures needed to accomplish a given task using computational micromagnetics. We also examine the effect of different simulation parameters to underscore and extend some best practices. Lastly, we examine different methods of micromagnetic analyses which are used to process simulation results in order to extract physically meaningful and valuable information.

  13. Sensitivity Analysis of Multidisciplinary Rotorcraft Simulations

    Science.gov (United States)

    Wang, Li; Diskin, Boris; Biedron, Robert T.; Nielsen, Eric J.; Bauchau, Olivier A.

    2017-01-01

    A multidisciplinary sensitivity analysis of rotorcraft simulations involving tightly coupled high-fidelity computational fluid dynamics and comprehensive analysis solvers is presented and evaluated. An unstructured sensitivity-enabled Navier-Stokes solver, FUN3D, and a nonlinear flexible multibody dynamics solver, DYMORE, are coupled to predict the aerodynamic loads and structural responses of helicopter rotor blades. A discretely-consistent adjoint-based sensitivity analysis available in FUN3D provides sensitivities arising from unsteady turbulent flows and unstructured dynamic overset meshes, while a complex-variable approach is used to compute DYMORE structural sensitivities with respect to aerodynamic loads. The multidisciplinary sensitivity analysis is conducted through integrating the sensitivity components from each discipline of the coupled system. Numerical results verify accuracy of the FUN3D/DYMORE system by conducting simulations for a benchmark rotorcraft test model and comparing solutions with established analyses and experimental data. Complex-variable implementation of sensitivity analysis of DYMORE and the coupled FUN3D/DYMORE system is verified by comparing with real-valued analysis and sensitivities. Correctness of adjoint formulations for FUN3D/DYMORE interfaces is verified by comparing adjoint-based and complex-variable sensitivities. Finally, sensitivities of the lift and drag functions obtained by complex-variable FUN3D/DYMORE simulations are compared with sensitivities computed by the multidisciplinary sensitivity analysis, which couples adjoint-based flow and grid sensitivities of FUN3D and FUN3D/DYMORE interfaces with complex-variable sensitivities of DYMORE structural responses.

  14. Analysis of principal parameters of forest fires and identification of desertification process in semi-arid land in Algeria

    Science.gov (United States)

    Zegrar, Ahmed

    2013-10-01

    In semi arid land in Algeria the ecosystem of steppe presents a different vegetal formation, generally used for pasture, and the forest are in most time composed by species like Aleppo pine sparse. And seen climatic unfavourable conditions in zone and impact of forest fires; we notes deterioration of physical environment particularly, deterioration of natural forest. This deterioration of forests provokes an unbalance of environment witch provokes a process of deterioration advanced in the ultimate stadium is desertification. The specific regeneration of plants are influenced greatly by the regime of fire (season of fire, intensity, interval), who leads to the recuperation of the vegetation of meadow- fire, but in the most case there are unfavourable climatic conditions. In this survey we used satellite data for detection of zones with risk of forest fire and their influenced parameters witch permit generally a desertification process. A thematic detailed analysis of forests ecosystems well attended, some processing on the satellite data (2003) allowed us to identify and classifying the forests in there opinion components flowers. We identified ampleness of fire on this zone also. The parameters slope, the proximity to the road and the forests formations and fire regime were studied in the goal of determining the zones to risk of fire drill. A crossing of information in a geographic information system according to a very determined logic allowed us to classify the zones in degree of risk of fire. These results compared with image data (2011) permit to conclude that in semi arid land the forest ecosystem after fire becomes steppe courses permitting installation of process of desertification.

  15. Modelling fires in the terrestrial carbon balance by incorporating SPITFIRE into the global vegetation model ORCHIDEE – Part 1: Simulating historical global burned area and fire regime

    CSIR Research Space (South Africa)

    Yue, C

    2014-01-01

    Full Text Available Modelling global burned area and fire regime C. Yue et al. Title Page Abstract Introduction Conclusions References Tables Figures J I J I Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion D iscussion P aper | D iscussion P aper | D... University, Bozeman, MT 59717, USA 2377 GMDD 7, 2377–2427, 2014 Modelling global burned area and fire regime C. Yue et al. Title Page Abstract Introduction Conclusions References Tables Figures J I J I Back Close Full Screen / Esc Printer-friendly Version...

  16. Analysis of the moderate resolution imaging spectroradiometer contextual algorithm for small fire detection

    Science.gov (United States)

    W. Wang; J.J. Qu; X. Hao; Y. Liu

    2009-01-01

    In the southeastern United States, most wildland fires are of low intensity. Asubstantial number of these fires cannot be detected by the MODIS contextual algorithm. Toimprove the accuracy of fire detection for this region, the remote-sensed characteristics ofthese fires have to be systematically...

  17. Simulation and Analysis of Chain Drive Systems

    DEFF Research Database (Denmark)

    Pedersen, Sine Leergaard

    The subject of this thesis is simulation and analysis of large roller chain drive systems, such as e.g. used in marine diesel engines. The aim of developing a chain drive simulation program is to analyse dynamic phenomena of chain drive systems and investigate different design changes...... to the systems, in order to remove unwanted phenomena. Such a computer program can, when properly validated, be used as an alternative to or in combination with physical experiments. Prior investigations in this area have been done with a focus on smaller chains in high speed chain drives. For large low speed...... systems other phenomena occur and therefore, a specific model of the marine engine chain drive is of interest. The research objective of the work presented in this thesis is to contribute with a novel theoretical basis for the analysis of chain drive systems, by posing and validating different...

  18. The effect of heat treatment simulating porcelain firing processes on titanium corrosion resistance.

    Science.gov (United States)

    Sokołowski, Grzegorz; Rylska, Dorota; Sokołowski, Jerzy

    2016-01-01

    Corrosion resistance of titanium used in metal-ceramic restorations in manufacturing is based on the presence of oxide layer on the metal surface. The procedures used during combining metallic material with porcelain may affect the changes in oxide layers structure, and thus anticorrosive properties of metallic material. The aim of the study was an evaluation of potential changes in the structure and selected corrosion properties of titanium after sandblasting and thermal treatment applicable to the processes of ceramics fusion. Milled titanium elements were subjected to a few variants of the processes typical of ceramics fusion and studied in terms of resistance to electrochemical corrosion. The study included the OCP changes over time, measurements of Icorr, Ecorr and Rp as well as potentiodynamic examinations. Surface microstructure and chemical composition were analyzed using SEM and EDS methods. The results obtained allow us to conclude that the processes corresponding to ceramic oxidation and fusion on titanium in the variants used in the study do not cause deterioration of its anticorrosive properties, and partially enhance the resistance. This depends on the quality of oxide layers structure. Titanium elements treated by porcelain firing processes do not lose their corrosion resistance.

  19. Use of 13C to monitor soil organic matter transformations caused by a simulated forest fire.

    Science.gov (United States)

    Fernandez, Irene; Cabaneiro, Ana; González-Prieto, Serafín J

    2004-01-01

    Soil organic matter (SOM) transformations caused by heating were analyzed using the stable carbon isotope (13)C as a tracer to follow C mineralization dynamics and C transfers between different organic compartments. A (13)C-labelled soil, obtained by incorporation of (13)C-enriched Lolium perenne phytomass into a pine forest soil, was heated for 10 min at 385 degrees C to reproduce conditions typical of a forest fire and changes in total C content, potential C mineralization activity and C distribution between the different soil organic fractions were determined. Changes caused by heating on the potential soil C mineralization, determined by laboratory aerobic incubation, reveal alterations to the SOM biodegradability; some stabilized SOM showed an increase in biodegradability, whereas less stabilized SOM became more resistant to microorganisms. Chemical fractionations of SOM allowed us to monitor changes in its composition. As a consequence of heating, the less polymerized humic fractions were the most strongly affected, with the total disappearance of fulvic acids. A significant increase in the quantity and degree of polymerization of the humic acids at the expense of other more (13)C-enriched substances was also found. Finally, a large decrease in humin was observed, its solubilizable part disappearing completely, probably as a consequence of the incorporation of the byproducts into the free organic matter fraction. Copyright 2004 John Wiley & Sons, Ltd.

  20. Methodology for Validating Building Energy Analysis Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Judkoff, R.; Wortman, D.; O' Doherty, B.; Burch, J.

    2008-04-01

    The objective of this report was to develop a validation methodology for building energy analysis simulations, collect high-quality, unambiguous empirical data for validation, and apply the validation methodology to the DOE-2.1, BLAST-2MRT, BLAST-3.0, DEROB-3, DEROB-4, and SUNCAT 2.4 computer programs. This report covers background information, literature survey, validation methodology, comparative studies, analytical verification, empirical validation, comparative evaluation of codes, and conclusions.

  1. National Infrastructure Simulation and Analysis Center Overview

    Energy Technology Data Exchange (ETDEWEB)

    Berscheid, Alan P. [Los Alamos National Laboratory

    2012-07-30

    National Infrastructure Simulation and Analysis Center (NISAC) mission is to: (1) Improve the understanding, preparation, and mitigation of the consequences of infrastructure disruption; (2) Provide a common, comprehensive view of U.S. infrastructure and its response to disruptions - Scale & resolution appropriate to the issues and All threats; and (3) Built an operations-tested DHS capability to respond quickly to urgent infrastructure protection issues.

  2. Laboratory Investigations of Ni-Al Coatings Exposed to Conditions Simulating Biomass Firing

    DEFF Research Database (Denmark)

    Wu, Duoli; Okoro, Sunday Chukwudi; Dahl, Kristian Vinter

    2016-01-01

    prepared by electrolytic deposition of nickel followed by pack aluminizing performed at 650˚C. A uniform and dense Ni-Al coating with an outer layer of Ni2Al3 and an inner Ni layer was formed. Samples were exposed to 560°C for 168h in an atmosphere simulating biomass combustion. This resulted in localized...

  3. Fire criticality probability analysis for 300 Area N Reactor fuel fabrication and storage facility. Revision 1

    International Nuclear Information System (INIS)

    Kelly, J.E.

    1995-01-01

    Uranium fuel assemblies and other uranium associated with the shutdown N Reactor are stored in the 300 Area N Reactor Fuel Fabrication and Storage Facility (Facility). The 3712 Building, where the majority of the fuel assemblies and other uranium is stored, is where there could be a potential for a criticality bounding case. The purpose of this study is to evaluate the probability of potential fires in the Facility 3712 Building that could lead to criticality. This study has been done to support the criticality update. For criticality to occur, the wooden fuel assembly containers would have to burn such that the fuel inside would slump into a critical geometry configuration, a sufficient number of containers burn to form an infinite wide configuration, and sufficient water (about a 17 inch depth) be placed onto the slump. To obtain the appropriate geometric configuration, enough fuel assembly containers to form an infinite array on the floor would have to be stacked at least three high. Administrative controls require the stacks to be limited to two high for 1.25 wt% enriched finished fuel. This is not sufficient to allow for a critical mass regardless of the fire and accompanying water moderation. It should be noted that 0.95 wt% enriched fuel and billets are stacked higher than only two high. In this analysis, two initiating events will be considered. The first is a random fire that is hot enough and sufficiently long enough to burn away the containers and fuel separators such that the fuel can establish a critical mass. The second is a seismically induced fire with the same results

  4. Fire criticality probability analysis for 300 Area N Reactor fuel fabrication and storage facility. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, J.E.

    1995-02-08

    Uranium fuel assemblies and other uranium associated with the shutdown N Reactor are stored in the 300 Area N Reactor Fuel Fabrication and Storage Facility (Facility). The 3712 Building, where the majority of the fuel assemblies and other uranium is stored, is where there could be a potential for a criticality bounding case. The purpose of this study is to evaluate the probability of potential fires in the Facility 3712 Building that could lead to criticality. This study has been done to support the criticality update. For criticality to occur, the wooden fuel assembly containers would have to burn such that the fuel inside would slump into a critical geometry configuration, a sufficient number of containers burn to form an infinite wide configuration, and sufficient water (about a 17 inch depth) be placed onto the slump. To obtain the appropriate geometric configuration, enough fuel assembly containers to form an infinite array on the floor would have to be stacked at least three high. Administrative controls require the stacks to be limited to two high for 1.25 wt% enriched finished fuel. This is not sufficient to allow for a critical mass regardless of the fire and accompanying water moderation. It should be noted that 0.95 wt% enriched fuel and billets are stacked higher than only two high. In this analysis, two initiating events will be considered. The first is a random fire that is hot enough and sufficiently long enough to burn away the containers and fuel separators such that the fuel can establish a critical mass. The second is a seismically induced fire with the same results.

  5. Model design to predict forest fire risk in Navarra (Spain) using time series analysis

    OpenAIRE

    Huesca, M.; Litago, J.; Palacios-Orueta, A.; Merino de Miguel, Silvia

    2008-01-01

    Understand and predict how forest fire potential changes over time are essential for prioritizing forest management activities and reducing damage. Nowadays we lack the capacity to predict future forest fire trends in response to climate change. The main goal of this research is to build an empirical model to describe, estimate and forecast the forest fires dynamics using the improved Fire Potential Index (FPI) (Huesca et al., 2007) as indicator of fire.

  6. Climatic and socio-economic fire drivers in the Mediterranean basin at a century scale: Analysis and modelling based on historical fire statistics and dynamic global vegetation models (DGVMs)

    Science.gov (United States)

    Mouillot, F.; Koutsias, N.; Conedera, M.; Pezzatti, B.; Madoui, A.; Belhadj Kheder, C.

    2017-12-01

    Wildfire is the main disturbance affecting Mediterranean ecosystems, with implications on biogeochemical cycles, biosphere/atmosphere interactions, air quality, biodiversity, and socio-ecosystems sustainability. The fire/climate relationship is time-scale dependent and may additionally vary according to concurrent changes climatic, environmental (e.g. land use), and fire management processes (e.g. fire prevention and control strategies). To date, however, most studies focus on a decadal scale only, being fire statistics ore remote sensing data usually available for a few decades only. Long-term fire data may allow for a better caption of the slow-varying human and climate constrains and for testing the consistency of the fire/climate relationship on the mid-time to better apprehend global change effects on fire risks. Dynamic Global Vegetation Models (DGVMs) associated with process-based fire models have been recently developed to capture both the direct role of climate on fire hazard and the indirect role of changes in vegetation and human population, to simulate biosphere/atmosphere interactions including fire emissions. Their ability to accurately reproduce observed fire patterns is still under investigation regarding seasonality, extreme events or temporal trend to identify potential misrepresentations of processes. We used a unique long-term fire reconstruction (from 1880 to 2016) of yearly burned area along a North/South and East/West environmental gradient across the Mediterranean Basin (southern Switzerland, Greece, Algeria, Tunisia) to capture the climatic and socio economic drivers of extreme fire years by linking yearly burned area with selected climate indices derived from historical climate databases and socio-economic variables. We additionally compared the actual historical reconstructed fire history with the yearly burned area simulated by a panel of DGVMS (FIREMIP initiative) driven by daily CRU climate data at 0.5° resolution across the

  7. Fire testing and analysis of TRUPACT-I Thermal Test Article

    International Nuclear Information System (INIS)

    Romesberg, L.E.; Longenbaugh, R.S.; Joseph, B.J.

    1989-02-01

    This report documents the fabrication and thermal test of a full-scale prototype of the revised TRUPACT-I design. The fire test demonstrated that the response of the Test Article to a jet-fueled pool fire, subsequent to the impact and puncture tests, meets the impact, puncture, and thermal performance requirements of the regulations governing transport of radioactive materials. The Test Article was a replica of the front half (closure end) of the revised TRUPACT-I design. To simulate the cumulative effect of the regulatory hypothetical accident sequence, the Test Article included the structural damage found in TRUPACT-I, Unit 0 after regulatory drop and puncture testing. The Test Article was totally engulfed in a pool fire fueled by JP-4 jet fuel for 46 minutes. The maximum temperature reached at the inner door seals was 149/degree/C (300/degree/F) and the maximum temperature at the inner door filters was 171/degree/C (340/degree/F). Both temperatures are within the normal working range for these components. Post-test leak rate measurements of 0.0041 atm-cm 3 /s (ANSI standard air) between the innermost pair of door seals and 0.0046 atm-cm 3 /s (ANSI standard air) between the outermost pair of door seals verified that the performance of the silicone seals met the design requirements. Since no detectable leakage was measured to a sensitivity of 1.0E-7 atm-cm 3 /s for the filter installation seal or quick-connect valve seal post-test, the total leak rate for the containment system was less than the maximum allowable 0.01 atm-cm 3 /s (ANSI standard air). 10 refs., 52 figs., 5 tabs

  8. Parallel proton fire hose instability in the expanding solar wind: Hybrid simulations

    Czech Academy of Sciences Publication Activity Database

    Matteini, L.; Landi, S.; Hellinger, Petr; Velli, M.

    2006-01-01

    Roč. 111, - (2006), A10101/1-A10101/8 ISSN 0148-0227 R&D Projects: GA AV ČR IAA3042403 Grant - others:European Commission(XE) HPRN-CT-2001-00310 Institutional research plan: CEZ:AV0Z30420517 Keywords : solar wind * kinetic instabilities * proton temperature anisotropy * simulation studies Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.800, year: 2006

  9. FireCalc: An XML-based framework for distributed data analysis

    International Nuclear Information System (INIS)

    Duarte, A.S.; Santos, J.H.; Fernandes, H.; Neto, A.; Pereira, T.; Varandas, C.A.F.

    2008-01-01

    Requirements and specifications for Control Data Access and Communication (CODAC) systems in fusion reactors point towards flexible and modular solutions, independent from operating system and computer architecture. These concepts can also be applied to calculation and data analysis systems, where highly standardized solutions must also apply in order to anticipate long time-scales and high technology evolution changes. FireCalc is an analysis tool based on standard Extensible Markup Language (XML) technologies. Actions are described in an XML file, which contains necessary data specifications and the code or references to scripts. This is used by the user to send the analysis code and data to a server, which can be running either locally or remotely. Communications between the user and the server are performed through XML-RPC, an XML based remote procedure call, thus enabling the client and server to be coded in different computer languages. Access to the database, security procedures and calls to the code interpreter are handled through independent modules, which unbinds them from specific solutions. Currently there is an implementation of the FireCalc framework in Java, that uses the Shared Data Access System (SDAS) for accessing the ISTTOK database and the Scilab kernel for the numerical analysis

  10. Isentropic Analysis of a Simulated Hurricane

    Science.gov (United States)

    Mrowiec, Agnieszka A.; Pauluis, Olivier; Zhang, Fuqing

    2016-01-01

    Hurricanes, like many other atmospheric flows, are associated with turbulent motions over a wide range of scales. Here the authors adapt a new technique based on the isentropic analysis of convective motions to study the thermodynamic structure of the overturning circulation in hurricane simulations. This approach separates the vertical mass transport in terms of the equivalent potential temperature of air parcels. In doing so, one separates the rising air parcels at high entropy from the subsiding air at low entropy. This technique filters out oscillatory motions associated with gravity waves and separates convective overturning from the secondary circulation. This approach is applied here to study the flow of an idealized hurricane simulation with the Weather Research and Forecasting (WRF) Model. The isentropic circulation for a hurricane exhibits similar characteristics to that of moist convection, with a maximum mass transport near the surface associated with a shallow convection and entrainment. There are also important differences. For instance, ascent in the eyewall can be readily identified in the isentropic analysis as an upward mass flux of air with unusually high equivalent potential temperature. The isentropic circulation is further compared here to the Eulerian secondary circulation of the simulated hurricane to show that the mass transport in the isentropic circulation is much larger than the one in secondary circulation. This difference can be directly attributed to the mass transport by convection in the outer rainband and confirms that, even for a strongly organized flow like a hurricane, most of the atmospheric overturning is tied to the smaller scales.

  11. Applying information network analysis to fire-prone landscapes: implications for community resilience

    Directory of Open Access Journals (Sweden)

    Derric B. Jacobs

    2017-03-01

    Full Text Available Resilient communities promote trust, have well-developed networks, and can adapt to change. For rural communities in fire-prone landscapes, current resilience strategies may prove insufficient in light of increasing wildfire risks due to climate change. It is argued that, given the complexity of climate change, adaptations are best addressed at local levels where specific social, cultural, political, and economic conditions are matched with local risks and opportunities. Despite the importance of social networks as key attributes of community resilience, research using social network analysis on coupled human and natural systems is scarce. Furthermore, the extent to which local communities in fire-prone areas understand climate change risks, accept the likelihood of potential changes, and have the capacity to develop collaborative mitigation strategies is underexamined, yet these factors are imperative to community resiliency. We apply a social network framework to examine information networks that affect perceptions of wildfire and climate change in Central Oregon. Data were collected using a mailed questionnaire. Analysis focused on the residents' information networks that are used to gain awareness of governmental activities and measures of community social capital. A two-mode network analysis was used to uncover information exchanges. Results suggest that the general public develops perceptions about climate change based on complex social and cultural systems rather than as patrons of scientific inquiry and understanding. It appears that perceptions about climate change itself may not be the limiting factor in these communities' adaptive capacity, but rather how they perceive local risks. We provide a novel methodological approach in understanding rural community adaptation and resilience in fire-prone landscapes and offer a framework for future studies.

  12. PARAMETERS AFFECTING THE STRUCTURAL ANALYSIS OF A TUNNEL STRUCTURE EXPOSED TO FIRE

    Directory of Open Access Journals (Sweden)

    Omid Pouran

    2016-12-01

    Full Text Available Behaviour of cut-and-cover tunnels exposed to fire should be analysed by using a realistic structural model that takes account of mechanical and thermal effects on the structure. This has been performed with the aid of Finite Element (FE software package called SOFiSTiK in parallel, for two types of elements as a scope of research project financed by the German Bundesanstalt für Straßenwesen BAST. Since the stiffness of the structure at elevated temperatures is highly affected, a realistic model of structural behaviour of the tunnel could be only achieved by considering the nonlinear analysis of the structure. This has been performed for a 2–cell cut and cover tunnel by taking account of simultaneous reduction of stiffness and strength and the time-dependent increasing indirect effects due to axial constraints and temperature gradients induced by elevated temperatures. The thermal analyses have been performed and the effects were implemented into the structural model by the multi-layered strain model. The stress–strain model proposed by EN 1992-1-2 is implemented for the elevated temperature. Since there was sufficient amount of Polypropylene fibres in the concrete mixtures, modelling of spalling was excluded from the analysis. The critical corresponding stresses and material behaviour are compared and interpreted at different time stages. The main parameters affecting the accuracy and convergence of the results of structural analysis for the used model are identified: defining a realistic fire action, using concrete material model fulfilling the requirements of fire situation in tunnels, defining appropriate time intervals for load implementations. These parameters along with other parameters, which influence the results to a lesser degree, are identified and investigated in this paper.

  13. Optoelectronic Devices Advanced Simulation and Analysis

    CERN Document Server

    Piprek, Joachim

    2005-01-01

    Optoelectronic devices transform electrical signals into optical signals and vice versa by utilizing the sophisticated interaction of electrons and light within micro- and nano-scale semiconductor structures. Advanced software tools for design and analysis of such devices have been developed in recent years. However, the large variety of materials, devices, physical mechanisms, and modeling approaches often makes it difficult to select appropriate theoretical models or software packages. This book presents a review of devices and advanced simulation approaches written by leading researchers and software developers. It is intended for scientists and device engineers in optoelectronics, who are interested in using advanced software tools. Each chapter includes the theoretical background as well as practical simulation results that help to better understand internal device physics. The software packages used in the book are available to the public, on a commercial or noncommercial basis, so that the interested r...

  14. Sample Analysis at Mars Instrument Simulator

    Science.gov (United States)

    Benna, Mehdi; Nolan, Tom

    2013-01-01

    The Sample Analysis at Mars Instrument Simulator (SAMSIM) is a numerical model dedicated to plan and validate operations of the Sample Analysis at Mars (SAM) instrument on the surface of Mars. The SAM instrument suite, currently operating on the Mars Science Laboratory (MSL), is an analytical laboratory designed to investigate the chemical and isotopic composition of the atmosphere and volatiles extracted from solid samples. SAMSIM was developed using Matlab and Simulink libraries of MathWorks Inc. to provide MSL mission planners with accurate predictions of the instrument electrical, thermal, mechanical, and fluid responses to scripted commands. This tool is a first example of a multi-purpose, full-scale numerical modeling of a flight instrument with the purpose of supplementing or even eliminating entirely the need for a hardware engineer model during instrument development and operation. SAMSIM simulates the complex interactions that occur between the instrument Command and Data Handling unit (C&DH) and all subsystems during the execution of experiment sequences. A typical SAM experiment takes many hours to complete and involves hundreds of components. During the simulation, the electrical, mechanical, thermal, and gas dynamics states of each hardware component are accurately modeled and propagated within the simulation environment at faster than real time. This allows the simulation, in just a few minutes, of experiment sequences that takes many hours to execute on the real instrument. The SAMSIM model is divided into five distinct but interacting modules: software, mechanical, thermal, gas flow, and electrical modules. The software module simulates the instrument C&DH by executing a customized version of the instrument flight software in a Matlab environment. The inputs and outputs to this synthetic C&DH are mapped to virtual sensors and command lines that mimic in their structure and connectivity the layout of the instrument harnesses. This module executes

  15. Development of an Optimizing Control Concept for Fossil-Fired Boilers using a Simulation Model

    DEFF Research Database (Denmark)

    Mortensen, J. H.; Mølbak, T.; Commisso, M.B.

    1997-01-01

    An optimizing control system for improving the load following capabilities of power plant units has been developed. The system is implemented as a complement producing additive control signals to the existing boiler control system, a concept which has various practical advantages in terms...... of implementation and commissioning. The optimizing control system takes into account the multivariable and nonlinear characteristics of the boiler process as a gain-scheduled LQG-controller is utilized. For the purpose of facilitating the control concept development a dynamic simulation model of the boiler process...

  16. Analysis of the behaviour of biofuel-fired gas turbine power plants

    Directory of Open Access Journals (Sweden)

    Escudero Marcos

    2012-01-01

    Full Text Available The utilisation of biofuels in gas turbines is a promising alternative to fossil fuels for power generation. It would lead to a significant reduction of CO2 emissions using an existing combustion technology, although considerable changes appear to be required and further technological development is necessary. The goal of this work is to conduct energy and exergy analyses of the behaviour of gas turbines fired with biogas, ethanol and synthesis gas (bio-syngas, compared with natural gas. The global energy transformation process (i.e., from biomass to electricity also has been studied. Furthermore, the potential reduction of CO2 emissions attained by the use of biofuels has been determined, after considering the restrictions regarding biomass availability. Two different simulation tools have been used to accomplish this work. The results suggest a high interest in, and the technical viability of, the use of Biomass Integrated Gasification Combined Cycle (BioIGCC systems for large scale power generation.

  17. Risk Management and Simulation Based Live Fire Test and Evaluation in the Performance Based Defense Business Environment

    National Research Council Canada - National Science Library

    Brown, R

    1999-01-01

    .... The service and acquisition program independent Live Fire Test and Evaluation Community has not fully recognized the changing defense acquisition business environment and modified policy and business...

  18. Mass Fire Model Concept

    Science.gov (United States)

    1981-05-31

    done by several investigators, the theoretical work of Nielsen (Reference 12) and Nielsen and Tao (Refer- ence 13) specifically models the global...which are approximately equal. This procedure permits computation of the fire..induced wind by a superpositlon of effects from each usub -fire." Outsid...Storm Analysis, ITT Research Institute, Janu- ary 1970. .324 13. Nielsen , H.J. and L.N. Tao, "The Fire Plume Above a Large Free- Burning Fire,’ Tenth S

  19. Fire History

    Data.gov (United States)

    California Department of Resources — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2002. Some fires...

  20. Fire Perimeters

    Data.gov (United States)

    California Department of Resources — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2003. Some fires...

  1. Fire Perimeters

    Data.gov (United States)

    California Natural Resource Agency — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2003. Some fires...

  2. Fire History

    Data.gov (United States)

    California Natural Resource Agency — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2002. Some fires...

  3. Simulating galaxies in the reionization era with FIRE-2: morphologies and sizes

    Science.gov (United States)

    Ma, Xiangcheng; Hopkins, Philip F.; Boylan-Kolchin, Michael; Faucher-Giguère, Claude-André; Quataert, Eliot; Feldmann, Robert; Garrison-Kimmel, Shea; Hayward, Christopher C.; Kereš, Dušan; Wetzel, Andrew

    2018-03-01

    We study the morphologies and sizes of galaxies at z ≥ 5 using high-resolution cosmological zoom-in simulations from the Feedback In Realistic Environments project. The galaxies show a variety of morphologies, from compact to clumpy to irregular. The simulated galaxies have more extended morphologies and larger sizes when measured using rest-frame optical B-band light than rest-frame UV light; sizes measured from stellar mass surface density are even larger. The UV morphologies are usually dominated by several small, bright young stellar clumps that are not always associated with significant stellar mass. The B-band light traces stellar mass better than the UV, but it can also be biased by the bright clumps. At all redshifts, galaxy size correlates with stellar mass/luminosity with large scatter. The half-light radii range from 0.01 to 0.2 arcsec (0.05-1 kpc physical) at fixed magnitude. At z ≥ 5, the size of galaxies at fixed stellar mass/luminosity evolves as (1 + z)-m, with m ˜ 1-2. For galaxies less massive than M* ˜ 108 M⊙, the ratio of the half-mass radius to the halo virial radius is ˜10% and does not evolve significantly at z = 5-10; this ratio is typically 1-5% for more massive galaxies. A galaxy's `observed' size decreases dramatically at shallower surface brightness limits. This effect may account for the extremely small sizes of z ≥ 5 galaxies measured in the Hubble Frontier Fields. We provide predictions for the cumulative light distribution as a function of surface brightness for typical galaxies at z = 6.

  4. Computer aided seismic and fire retrofitting analysis of existing high rise reinforced concrete buildings

    CERN Document Server

    Hussain, Raja Rizwan; Hasan, Saeed

    2016-01-01

    This book details the analysis and design of high rise buildings for gravity and seismic analysis. It provides the knowledge structural engineers need to retrofit existing structures in order to meet safety requirements and better prevent potential damage from such disasters as earthquakes and fires. Coverage includes actual case studies of existing buildings, reviews of current knowledge for damages and their mitigation, protective design technologies, and analytical and computational techniques. This monograph also provides an experimental investigation on the properties of fiber reinforced concrete that consists of natural fibres like coconut coir and also steel fibres that are used for comparison in both Normal Strength Concrete (NSC) and High Strength Concrete (HSC). In addition, the authors examine the use of various repair techniques for damaged high rise buildings. The book will help upcoming structural design engineers learn the computer aided analysis and design of real existing high rise buildings ...

  5. A probabilistic analysis of fire-induced tree-grass coexistence in savannas.

    Science.gov (United States)

    D'Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

    2006-03-01

    Fires play an important role in determining the composition and structure of vegetation in semiarid ecosystems. The study of the interactions between fire and vegetation requires a stochastic approach because of the random and unpredictable nature of fire occurrences. To this end, this article develops a minimalist probabilistic framework to investigate the impact of intermittent fire occurrences on the temporal dynamics of vegetation. This framework is used to analyze the emergence of statistically stable conditions favorable to tree-grass coexistence in savannas. It is found that these conditions can be induced and stabilized by the stochastic fire regime. A decrease in fire frequency leads to bush encroachment, while more frequent and intense fires favor savanna-to-grassland conversions. The positive feedback between fires and vegetation can convert states of tree-grass coexistence in semiarid savannas into bistable conditions, with both woodland and grassland as possible, though mutually exclusive, stable states of the system.

  6. 309 Building fire protection analysis and justification for deactivation of sprinkler system. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Conner, R.P.

    1997-06-25

    Provide a `graded approach` fire evaluation in preparation for turnover to Environmental Restoration Contractor for D&D. Scope includes revising 309 Building book value and evaluating fire hazards, radiological and toxicological releases, and life safety issues.

  7. Methods for Prediction of Steel Temperature Curve in the Whole Process of a Localized Fire in Large Spaces

    Directory of Open Access Journals (Sweden)

    Zhang Guowei

    2014-01-01

    Full Text Available Based on a full-scale bookcase fire experiment, a fire development model is proposed for the whole process of localized fires in large-space buildings. We found that for localized fires in large-space buildings full of wooden combustible materials the fire growing phases can be simplified into a t2 fire with a 0.0346 kW/s2 fire growth coefficient. FDS technology is applied to study the smoke temperature curve for a 2 MW to 25 MW fire occurring within a large space with a height of 6 m to 12 m and a building area of 1 500 m2 to 10 000 m2 based on the proposed fire development model. Through the analysis of smoke temperature in various fire scenarios, a new approach is proposed to predict the smoke temperature curve. Meanwhile, a modified model of steel temperature development in localized fire is built. In the modified model, the localized fire source is treated as a point fire source to evaluate the flame net heat flux to steel. The steel temperature curve in the whole process of a localized fire could be accurately predicted by the above findings. These conclusions obtained in this paper could provide valuable reference to fire simulation, hazard assessment, and fire protection design.

  8. GEOMETRIC AND MATERIAL NONLINEAR ANALYSIS OF REINFORCED CONCRETE SLABS AT FIRE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ayad A. Abdul -Razzak

    2013-05-01

    Full Text Available In the present study a nonlinear finite element analysis is presented  to predict the fire resistance of reinforced concrete slabs at fire environment. An eight node layered degenerated shell element utilizing Mindlin/Reissner thick plate theory is employed. The proposed model considered cracking, crushing and yielding of concrete and steel at elevated temperatures. The layered approach is used to represent the steel reinforcement and discretize the concrete slab through the thickness. The reinforcement steel is represented as a smeared layer of equivalent thickness with uniaxial strength and rigidity properties.Geometric nonlinear analysis may play an important role in the behavior of reinforced concrete slabs at high temperature. Geometrical nonlinearity in the layered approach is considered in the mathematical model, which is based on the total Lagrangian approach taking into account Von Karman assumptions.Finally two examples for which experimental results are available are analyzed, using the proposed model .The comparison showed good agreement with experimental results. 

  9. GIS-BASED MULTI-CRITERIA DECISION ANALYSIS FOR FOREST FIRE RISK MAPPING

    OpenAIRE

    A. E. Akay; A. Erdoğan

    2017-01-01

    The forested areas along the coastal zone of the Mediterranean region in Turkey are classified as first-degree fire sensitive areas. Forest fires are major environmental disaster that affects the sustainability of forest ecosystems. Besides, forest fires result in important economic losses and even threaten human lives. Thus, it is critical to determine the forested areas with fire risks and thereby minimize the damages on forest resources by taking necessary precaution measures in these area...

  10. Simulating the interactions of forest structure, fire regime, and plant invasion in the southern Appalachians using LANDIS

    Science.gov (United States)

    Weimin Xi; Szu-Hung Chen; Andrew G. Birt; John D. Waldron; Charles W. Lafon; David M. Cairns; Maria D. Tchakerian; Kier D. Klepzig; Robert N. Coulson

    2011-01-01

    Southern Appalachian forests face multiple environmental threats, including periodic fires, insect outbreaks, and more recently, exotic invasive plants. Past studies suggest these multiple disturbances interact to shape species-rich forest landscape, and they hypothesize that changes in fire regimes and increasing landscape fragmentation may influence invasive...

  11. Chapter 10 - Using simulation modeling to assess historical reference conditions for vegetation and fire regimes for the LANDFIRE Prototype Project

    Science.gov (United States)

    Sarah Pratt; Lisa Holsinger; Robert E. Keane

    2006-01-01

    A critical component of the Landscape Fire and Resource Management Planning Tools Prototype Project, or LANDFIRE Prototype Project, was the development of a nationally consistent method for estimating historical reference conditions for vegetation composition and structure and wildland fire regimes. These estimates of past vegetation composition and condition are used...

  12. Multiscale simulation of a prescribed fire event in the New Jersey Pine Barrens using ARPS-CANOPY

    Science.gov (United States)

    Michael T. Kiefer; Warren E. Heilman; Shiyuan Zhong; Joseph J. Charney; Xindi Bian; Nicholas S. Skowronski; John L. Hom; Kenneth L. Clark; Matthew Patterson; Michael R. Gallagher

    2014-01-01

    Smoke prediction products are one of the tools used by land management personnel for decision making regarding prescribed fires. This study documents the application to a prescribed fire of a smoke prediction system that employs ARPS-CANOPY, a modified version of the Advanced Regional Prediction System (ARPS) model containing a canopy submodel, as the meteorological...

  13. Simulation of the Fuel Reactor of a Coal-Fired Chemical Looping Combustor

    Science.gov (United States)

    Mahalatkar, Kartikeya; O'Brien, Thomas; Huckaby, E. David; Kuhlman, John

    2009-06-01

    removed from the bed and returned to the air reactor without any accompanying unburned fuel. This paper presents a simulation of the gas-particle granular flow, with heat transfer and chemical reactions, in the FR. Accurate simulation of the segregation processes, depending on particle density and size differences between the carrier and the fuel, allows the design of a reactor with the desired behavior.

  14. Fire damage data analysis as related to current testing practices for nuclear power applications

    International Nuclear Information System (INIS)

    Klevan, J.; MacDougall, E.A.; Hall, R.E.

    1978-01-01

    A review of reports of specific fires which have occurred in nuclear power plants in the United States is presented. A limited comparison of cable and similar fires with results of the IEEE 383 fire test used to evaluate cable insulation is also presented

  15. Risk of commercial truck fires in the United States : an exploratory data analysis

    Science.gov (United States)

    2012-06-29

    Large trucks are involved in only 8 percent of fatal crashes per year, but 17 percent of fatal fires. The scope of the current body of research is limited. Studies have treated truck fires generally as a subset of vehicle fires or in their own right ...

  16. Performance analysis of US coal-fired power plants by measuring three DEA efficiencies

    International Nuclear Information System (INIS)

    Sueyoshi, Toshiyuki; Goto, Mika; Ueno, Takahiro

    2010-01-01

    Data Envelopment Analysis (DEA) has been widely used for performance evaluation of many organizations in private and public sectors. This study proposes a new DEA approach to evaluate the operational, environmental and both-unified performance of coal-fired power plants that are currently operating under the US Clean Air Act (CAA). The economic activities of power plants examined by this study are characterized by four inputs, a desirable (good) output and three undesirable (bad) outputs. This study uses Range-Adjusted Measure (RAM) because it can easily incorporate both desirable and undesirable outputs in the unified analytical structure. The output unification proposed in this study has been never investigated in the previous DEA studies even though such a unified measure is essential in guiding policy makers and corporate leaders. Using the proposed DEA approach, this study finds three important policy implications. First, the CAA has been increasingly effective on their environmental protection. The increased environmental performance leads to the enhancement of the unified efficiency. Second, the market liberalization/deregulation was an important business trend in the electric power industry. Such a business trend was legally prepared by US Energy Policy Act (EPAct). According to the level of the market liberalization, the United States is classified into regulated and deregulated states. This study finds that the operational and unified performance of coal-fired power plants in the regulated states outperforms those of the deregulated states because the investment on coal-fired power plants in the regulated states can be utilized as a financial tool under the rate-of-return criterion of regulation. The power plants in the deregulated states do not have such a regulation premium. Finally, plant managers need to balance between their environmental performance and operational efficiency. (author)

  17. Greenhouse gas emission measurement and economic analysis of Iran natural gas fired power plants

    International Nuclear Information System (INIS)

    Shahsavari Alavijeh, H.; Kiyoumarsioskouei, A.; Asheri, M.H.; Naemi, S.; Shahsavari Alavije, H.; Basirat Tabrizi, H.

    2013-01-01

    This study attempts to examine the natural gas fired power plants in Iran. The required data from natural gas fired power plants were gathered during 2008. The characteristics of thirty two gas turbine power plants and twenty steam power plants have been measured. Their emission factor values were then compared with the standards of Energy Protection Agency, Euro Union and World Bank. Emission factors of gas turbine and steam power plants show that gas turbine power plants have a better performance than steam power plants. For economic analysis, fuel consumption and environmental damages caused by the emitted pollutants are considered as cost functions; and electricity sales revenue are taken as benefit functions. All of these functions have been obtained according to the capacity factor. Total revenue functions show that gas turbine and steam power plants are economically efficient at 98.15% and 90.89% of capacity factor, respectively; this indicates that long operating years of power plants leads to reduction of optimum capacity factor. The stated method could be implemented to assess the economic status of a country’s power plants where as efficient capacity factor close to one means that power plant works in much better condition. - Highlights: • CO 2 and NO x emissions of Iran natural gas fired power plants have been studied. • CO 2 and NO x emission factors are compared with EPA, EU and World Bank standards. • Costs and benefit as economic functions are obtained according to capacity factor. • Maximum economic profit is obtained for gas turbine and steam power plants. • Investment in CO 2 reduction is recommended instead of investment in NO x reduction

  18. All fired up

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    Members of the Directorate and their support staff took part in a fire-fighting course organised by the CERN Fire Brigade just before the end-of-year break.  The Bulletin takes a look at the fire-fighting training on offer at CERN.   At CERN the risk of fire can never be under-estimated. In order to train personnel in the use of fire extinguishers, CERN's fire training centre in Prévessin acquired a fire-simulation platform in 2012. On the morning of 17 December 2012, ten members of the CERN directorate and their support staff tried out the platform, following in the footsteps of 400 other members of the CERN community who had already attended the course. The participants were welcomed to the training centre by Gilles Colin, a fire-fighter and instructor, who gave them a 30-minute introduction to general safety and the different types of fire and fire extinguishers, followed by an hour of practical instruction in the simulation facility. There they were able to pract...

  19. Simulation and Non-Simulation Based Human Reliability Analysis Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Boring, Ronald Laurids [Idaho National Lab. (INL), Idaho Falls, ID (United States); Shirley, Rachel Elizabeth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Joe, Jeffrey Clark [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-12-01

    Part of the U.S. Department of Energy’s Light Water Reactor Sustainability (LWRS) Program, the Risk-Informed Safety Margin Characterization (RISMC) Pathway develops approaches to estimating and managing safety margins. RISMC simulations pair deterministic plant physics models with probabilistic risk models. As human interactions are an essential element of plant risk, it is necessary to integrate human actions into the RISMC risk model. In this report, we review simulation-based and non-simulation-based human reliability assessment (HRA) methods. Chapter 2 surveys non-simulation-based HRA methods. Conventional HRA methods target static Probabilistic Risk Assessments for Level 1 events. These methods would require significant modification for use in dynamic simulation of Level 2 and Level 3 events. Chapter 3 is a review of human performance models. A variety of methods and models simulate dynamic human performance; however, most of these human performance models were developed outside the risk domain and have not been used for HRA. The exception is the ADS-IDAC model, which can be thought of as a virtual operator program. This model is resource-intensive but provides a detailed model of every operator action in a given scenario, along with models of numerous factors that can influence operator performance. Finally, Chapter 4 reviews the treatment of timing of operator actions in HRA methods. This chapter is an example of one of the critical gaps between existing HRA methods and the needs of dynamic HRA. This report summarizes the foundational information needed to develop a feasible approach to modeling human interactions in the RISMC simulations.

  20. CFD analysis of temperature imbalance in superheater/reheater region of tangentially coal-fired boiler

    Science.gov (United States)

    Zainudin, A. F.; Hasini, H.; Fadhil, S. S. A.

    2017-10-01

    This paper presents a CFD analysis of the flow, velocity and temperature distribution in a 700 MW tangentially coal-fired boiler operating in Malaysia. The main objective of the analysis is to gain insights on the occurrences in the boiler so as to understand the inherent steam temperature imbalance problem. The results show that the root cause of the problem comes from the residual swirl in the horizontal pass. The deflection of the residual swirl due to the sudden reduction and expansion of the flow cross-sectional area causes velocity deviation between the left and right side of the boiler. This consequently results in flue gas temperature imbalance which has often caused tube leaks in the superheater/reheater region. Therefore, eliminating the residual swirl or restraining it from being diverted might help to alleviate the problem.

  1. Analysis and simulation of straw fuel logistics

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Daniel [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Agricultural Engineering

    1998-12-31

    Straw is a renewable biomass that has a considerable potential to be used as fuel in rural districts. This bulky fuel is, however, produced over large areas and must be collected during a limited amount of days and taken to the storages before being ultimately transported to heating plants. Thus, a well thought-out and cost-effective harvesting and handling system is necessary to provide a satisfactory fuel at competitive costs. Moreover, high-quality non-renewable fuels are used in these operations. To be sustainable, the energy content of these fuels should not exceed the energy extracted from the straw. The objective of this study is to analyze straw as fuel in district heating plants with respect to environmental and energy aspects, and to improve the performance and reduce the costs of straw handling. Energy, exergy and emergy analyses were used to assess straw as fuel from an energy point of view. The energy analysis showed that the energy balance is 12:1 when direct and indirect energy requirements are considered. The exergy analysis demonstrated that the conversion step is ineffective, whereas the emergy analysis indicated that large amounts of energy have been used in the past to form the straw fuel (the net emergy yield ratio is 1.1). A dynamic simulation model, called SHAM (Straw HAndling Model), has also been developed to investigate handling of straw from the fields to the plant. The primary aim is to analyze the performance of various machinery chains and management strategies in order to reduce the handling costs and energy needs. The model, which is based on discrete event simulation, takes both weather and geographical conditions into account. The model has been applied to three regions in Sweden (Svaloev, Vara and Enkoeping) in order to investigate the prerequisites for straw harvest at these locations. The simulations showed that straw has the best chances to become a competitive fuel in south Sweden. It was also demonstrated that costs can be

  2. Economic analysis of atmospheric mercury emission control for coal-fired power plants in China.

    Science.gov (United States)

    Ancora, Maria Pia; Zhang, Lei; Wang, Shuxiao; Schreifels, Jeremy; Hao, Jiming

    2015-07-01

    Coal combustion and mercury pollution are closely linked, and this relationship is particularly relevant in China, the world's largest coal consumer. This paper begins with a summary of recent China-specific studies on mercury removal by air pollution control technologies and then provides an economic analysis of mercury abatement from these emission control technologies at coal-fired power plants in China. This includes a cost-effectiveness analysis at the enterprise and sector level in China using 2010 as a baseline and projecting out to 2020 and 2030. Of the control technologies evaluated, the most cost-effective is a fabric filter installed upstream of the wet flue gas desulfurization system (FF+WFGD). Halogen injection (HI) is also a cost-effective mercury-specific control strategy, although it has not yet reached commercial maturity. The sector-level analysis shows that 193 tons of mercury was removed in 2010 in China's coal-fired power sector, with annualized mercury emission control costs of 2.7 billion Chinese Yuan. Under a projected 2030 Emission Control (EC) scenario with stringent mercury limits compared to Business As Usual (BAU) scenario, the increase of selective catalytic reduction systems (SCR) and the use of HI could contribute to 39 tons of mercury removal at a cost of 3.8 billion CNY. The economic analysis presented in this paper offers insights on air pollution control technologies and practices for enhancing atmospheric mercury control that can aid decision-making in policy design and private-sector investments. Copyright © 2015. Published by Elsevier B.V.

  3. Ash fouling monitoring and key variables analysis for coal fired power plant boiler

    Directory of Open Access Journals (Sweden)

    Shi Yuanhao

    2015-01-01

    Full Text Available Ash deposition on heat transfer surfaces is still a significant problem in coal-fired power plant utility boilers. The effective ways to deal with this problem are accurate on-line monitoring of ash fouling and soot-blowing. In this paper, an online ash fouling monitoring model based on dynamic mass and energy balance method is developed and key variables analysis technique is introduced to study the internal behavior of soot-blowing system. In this process, artificial neural networks (ANN are used to optimize the boiler soot-blowing model and mean impact values method is utilized to determine a set of key variables. The validity of the models has been illustrated in a real case-study boiler, a 300MW Chinese power station. The results on same real plant data show that both models have good prediction accuracy, while the ANN model II has less input parameters. This work will be the basis of a future development in order to control and optimize the soot-blowing of the coal-fired power plant utility boilers.

  4. The Science of Transportation Analysis and Simulation

    Science.gov (United States)

    Gleibe, John

    2010-03-01

    Transportation Science focuses on methods developed to model and analyze the interaction between human behavior and transportation systems. From the human behavioral, or demand, perspective, we are interested in how person and households organize their activities across space and time, with travel viewed as an enabling activity. We have a particular interest in how to model the range of responses to public policy and transportation system changes, which leads to the consideration of both short- and long-term decision-making, interpersonal dependencies, and non-transportation-related opportunities and constraints, including household budgets, land use systems and economic systems. This has led to the development of complex structural econometric modeling systems as well as agent-based simulations. From the transportation systems, or supply, perspective we are interested in the level of service provide by transportation facilities, be it auto, transit or multi-modal systems. This has led to the development of network models and equilibrium concepts as well as hybrid simulation systems based on concepts borrowed from physics, such as fluid flow models, and cellular automata-type models. In this presentation, we review a representative sample of these methods and their use in transportation planning and public policy analysis.

  5. Analysis of the Shallow Groundwater Flow System at Fire Island National Seashore, Suffolk County, New York

    Science.gov (United States)

    Schubert, Christopher E.

    2010-01-01

    Fire Island National Seashore (FIIS) occupies 42 kilometers of the barrier island for which it is named that lies off the southern shore of Suffolk County, N.Y. Freshwater in the highly permeable, sandy aquifer underlying Fire Island is bounded laterally by marine surface waters and at depth by saline groundwater. Interspersed throughout FIIS are 17 pre-existing residential communities that in summer months greatly increase in population through the arrival of summer residents and vacationers; in addition, the National Park Service (NPS) has established several facilities on the island to accommodate visitors to FIIS. The 2.2 million people estimated by the NPS to visit Fire Island annually impact groundwater quality through the release of waste-derived contaminants, such as nutrients, pathogens, and organic compounds, into the environment. Waste-contaminated groundwater can move through the aquifer and threaten the ecological health of the adjacent back-barrier estuaries to which much of the groundwater ultimately discharges. In 2004, the U.S. Geological Survey (USGS), in cooperation with the NPS, began a 3-year investigation to (1) collect groundwater levels and water-quality (nutrient) samples, (2) develop a three-dimensional model of the shallow (water-table) aquifer system and adjacent marine surface waters, and (3) calculate nitrogen loads in simulated groundwater discharges from the aquifer to back-barrier estuaries and the ocean. The hydrogeology of the shallow aquifer system was characterized from the results of exploratory drilling, geophysical surveying, water-level monitoring, and water-quality sampling. The investigation focused on four areas-the communities of Kismet and Robbins Rest, the NPS Visitor Center at Watch Hill, and the undeveloped Otis Pike Fire Island High Dune Wilderness. Thirty-five observation wells were installed within FIIS to characterize subsurface hydrogeology and establish a water-table monitoring network in the four study areas

  6. Wetland fire scar monitoring and analysis using archival Landsat data for the Everglades

    Science.gov (United States)

    Jones, John W.; Hall, Annette E.; Foster, Ann M.; Smith, Thomas J.

    2013-01-01

    The ability to document the frequency, extent, and severity of fires in wetlands, as well as the dynamics of post-fire wetland land cover, informs fire and wetland science, resource management, and ecosystem protection. Available information on Everglades burn history has been based on field data collection methods that evolved through time and differ by land management unit. Our objectives were to (1) design and test broadly applicable and repeatable metrics of not only fire scar delineation but also post-fire land cover dynamics through exhaustive use of the Landsat satellite data archives, and then (2) explore how those metrics relate to various hydrologic and anthropogenic factors that may influence post-fire land cover dynamics. Visual interpretation of every Landsat scene collected over the study region during the study time frame produced a new, detailed database of burn scars greater than 1.6 ha in size in the Water Conservation Areas and post-fire land cover dynamics for Everglades National Park fires greater than 1.6 ha in area. Median burn areas were compared across several landscape units of the Greater Everglades and found to differ as a function of administrative unit and fire history. Some burned areas transitioned to open water, exhibiting water depths and dynamics that support transition mechanisms proposed in the literature. Classification tree techniques showed that time to green-up and return to pre-burn character were largely explained by fire management practices and hydrology. Broadly applicable as they use data from the global, nearly 30-year-old Landsat archive, these methods for documenting wetland burn extent and post-fire land cover change enable cost-effective collection of new data on wetland fire ecology and independent assessment of fire management practice effectiveness.

  7. The economics of fire protection

    CERN Document Server

    Ramachandran, Ganapathy

    2003-01-01

    This important new book, the first of its kind in the fire safety field, discusses the economic problems faced by decision-makers in the areas of fire safety and fire precautions. The author considers the theoretical aspects of cost-benefit analysis and other relevant economic problems with practical applications to fire protection systems. Clear examples are included to illustrate these techniques in action. The work covers: * the performance and effectiveness of passive fire protection measures such as structural fire resistance and means of escape facilities, and active systems such as sprinklers and detectors * the importance of educating for better understanding and implementation of fire prevention through publicity campaigns and fire brigade operations * cost-benefit analysis of fire protection measures and their combinations, taking into account trade-offs between these measures. The book is essential reading for consultants and academics in construction management, economics and fire safety, as well ...

  8. Aircraft Fire Protection Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Navy Aircraft Protection Laboratory provides complete test support for all Navy air vehicle fire protection systems.The facility allows for the simulation of a...

  9. Numerical modelling of fire propagation: principles and applications at Electricite de France; La simulation numerique d`incendie: principe et applications a Electricite de France

    Energy Technology Data Exchange (ETDEWEB)

    Rongere, F.X.; Gibault, J.

    1994-05-01

    Electricite de France, wishing to limit the accidental unavailability of its nuclear plants and to ensure their safety rigorously takes particular care to reduce the risk of fire. In this context, the Heat Transfer and Aerodynamics Branch of the Research and Development Division has been in charge of the design of numerical tools to simulate the fire propagation in buildings since 1985. Its program is articulated towards three axes which include : the development of the MAGIC software program, the characterization of the combustibles present in power plants, the development of methods for the use of the computer codes in the design of plants. This paper gives on overview of the activity in progress in this research fields. It illustrates also the applications performed and anticipated at Electricite de France of the numerical simulation in fire safety design. We discuss at the end of it the limitations and the development factors of these tool use. One of the later is the association of MAGIC software and the FIVE method. (authors). 15 refs., 10 figs., 2 tabs.

  10. Analysis and Selection of the Simulation Environment

    OpenAIRE

    Giulioni, Gianfranco; Zini, Floriano

    2005-01-01

    This document provides the initial report of the Simulation work package (Work Package 4,WP4) of the CATNETS project. It contains an analisys of the requirements for a simulation tool to be used in CATNETS and an evaluation of a number of grid and general purpose simulators with respect to the selected requirements. A reasoned choice of a suitable simulator is performed based on the evaluation conducted. Diese Arbeit analysiert die Anforderungen an eine Simulationsumgebung für die Analyse ...

  11. [Hazard evaluation modeling of particulate matters emitted by coal-fired boilers and case analysis].

    Science.gov (United States)

    Shi, Yan-Ting; Du, Qian; Gao, Jian-Min; Bian, Xin; Wang, Zhi-Pu; Dong, He-Ming; Han, Qiang; Cao, Yang

    2014-02-01

    In order to evaluate the hazard of PM2.5 emitted by various boilers, in this paper, segmentation of particulate matters with sizes of below 2. 5 microm was performed based on their formation mechanisms and hazard level to human beings and environment. Meanwhile, taking into account the mass concentration, number concentration, enrichment factor of Hg, and content of Hg element in different coal ashes, a comprehensive model aimed at evaluating hazard of PM2.5 emitted by coal-fired boilers was established in this paper. Finally, through utilizing filed experimental data of previous literatures, a case analysis of the evaluation model was conducted, and the concept of hazard reduction coefficient was proposed, which can be used to evaluate the performance of dust removers.

  12. Cause analysis and suggestion of urea consumption in denitrification system of coal-fired power plant

    Science.gov (United States)

    Zhang, Xueying; Dong, Ruifeng; Guo, Yang; Wang, Fangfang; Yang, Shuo

    2018-02-01

    In the daily operation of many power plants, the urea consumption of denitration system is much more than normal. Therefore, the process of site testing and laboratory analysis are carried out. Several suggestions are given out. (1) The position of sampling hole on the exit flue of denitrification system should be redesigned. (2) The denitrification optimization and adjustment should be carried out based on the technical specifications for the operation system. (3) The flue gas CEMS system for single point sampling should be transformed into two or three point sampling mode. (4) When the coal - fired unit is shutting down, examine the ammonia injection and nozzle branch, in order to improve the operation reliability of denitration system.

  13. Thermodynamic analysis and conceptual design for partial coal gasification air preheating coal-fired combined cycle

    Science.gov (United States)

    Xu, Yue; Wu, Yining; Deng, Shimin; Wei, Shirang

    2004-02-01

    The partial coal gasification air pre-heating coal-fired combined cycle (PGACC) is a cleaning coal power system, which integrates the coal gasification technology, circulating fluidized bed technology, and combined cycle technology. It has high efficiency and simple construction, and is a new selection of the cleaning coal power systems. A thermodynamic analysis of the PGACC is carried out. The effects of coal gasifying rate, pre-heating air temperature, and coal gas temperature on the performances of the power system are studied. In order to repower the power plant rated 100 MW by using the PGACC, a conceptual design is suggested. The computational results show that the PGACC is feasible for modernizing the old steam power plants and building the new cleaning power plants.

  14. Computer simulation, nuclear techniques and surface analysis

    Directory of Open Access Journals (Sweden)

    Reis, A. D.

    2010-02-01

    Full Text Available This article is about computer simulation and surface analysis by nuclear techniques, which are non-destructive. The “energy method of analysis” for nuclear reactions is used. Energy spectra are computer simulated and compared with experimental data, giving target composition and concentration profile information. Details of prediction stages are given for thick flat target yields. Predictions are made for non-flat targets having asymmetric triangular surface contours. The method is successfully applied to depth profiling of 12C and 18O nuclei in thick targets, by deuteron (d,p and proton (p,α induced reactions, respectively.

    Este artículo trata de simulación por ordenador y del análisis de superficies mediante técnicas nucleares, que son no destructivas. Se usa el “método de análisis en energía” para reacciones nucleares. Se simulan en ordenador espectros en energía que se comparan con datos experimentales, de lo que resulta la obtención de información sobre la composición y los perfiles de concentración de la muestra. Se dan detalles de las etapas de las predicciones de espectros para muestras espesas y planas. Se hacen predicciones para muestras no planas que tienen contornos superficiales triangulares asimétricos. Este método se aplica con éxito en el cálculo de perfiles en profundidad de núcleos de 12C y de 18O en muestras espesas a través de reacciones (d,p y (p,α inducidas por deuterones y protones, respectivamente.

  15. Fire hazard analysis for the Westinghouse Hanford Company managed low-level mixed waste Trench 31 and 34

    International Nuclear Information System (INIS)

    Howard, B.J.

    1995-01-01

    This analysis is to assess comprehensively the risks from fire within the new lined landfills, provided by W-025 and designated Trench 31 and 34 of Burial Ground 218-W-5; they are located in the 200 West area of the Hanford Site, and are designed to receive low-level mixed waste

  16. Safety during sea transport of radioactive materials. Probabilistic safety analysis of package fro sea surface fire accident

    International Nuclear Information System (INIS)

    Matsuoka, Takeshi; Obara, Isonori; Akutsu, Yukio; Aritomi, Masanori

    2000-01-01

    The ships carrying irradiated nuclear fuel, plutonium and high level radioactive wastes(INF materials) are designed to keep integrity of packaging based on the various safety and fireproof measures, even if the ship encounters a maritime fire accident. However, granted that the frequency is very low, realistic severe accidents should be evaluated. In this paper, probabilistic safety assessment method is applied to evaluate safety margin for severe sea fire accidents using event tree analysis. Based on our separate studies, the severest scenario was estimated as follows; an INF transport ship collides with oil tanker and induces a sea surface fire. Probability data such as ship's collision, oil leakage, ignition, escape from fire region, operations of cask cooling system and water flooding systems were also introduced from above mentioned studies. The results indicate that the probability of which packages cannot keep their integrity during the sea surface fire accident is very low and sea transport of INF materials is carried out very safely. (author)

  17. Managing Fire in the Northern Chihuahuan Desert: A Review and Analysis of the Literature

    Science.gov (United States)

    Gebow, Brooke S.; Halvorson, William L.

    2005-01-01

    Executive Summary This report began as a literature review (Gebow and Halvorson 2001) conducted for fire planners at Carlsbad Caverns National Park who were seeking information about (1) the natural state of park vegetation, (2) northern Chihuahuan Desert natural fire regimes, and (3) fire effects on park plant species. It is the goal of managers there to continue to refine the wildland and prescribed fire program as they learn more about the ecosystems at the park.The park has a history of grazing and then fire suppression in the 20th century. The current effort revisits questions asked by earlier workers at the park, Walter Kittams and Gary Ahlstrand, who began fire studies in the 1970s. This document addresses ecosystems and historical change to those systems in Chihuahuan Desert areas of southeast Arizona, southern New Mexico, west Texas, or in neighboring regions that share the same plant species. It examines fire literature for situations possibly analogous to those at Carlsbad Caverns. It also includes papers that offer advice on extrapolating future ecological trends from past ones (Swetnam et al. 1999) and on resource management decision-making (Grumbine 1997), and other pieces that address broader aspects of fire or landscape change (Goldman 1994; Marston 1996; Mutch 1994, 1995). These more philosophical works were included in the original review at the park's request and have been retained here because they discuss other issues relevant to fire management. Individual reviews of 35 papers, as requested originally by Carlsbad Caverns, appear in Appendix 1. The results section-summary of key findings-discusses historical changes to plant communities then focuses on burn intervals observed or recommended by workers for particular plant communities. Results from a search of the USDA Forest Service's Fire Effects Information System (www.fs.fed.us/database/feis) are also included in this report, supplemented with information from a review conducted by Ahlstrand

  18. Experimental Design for Sensitivity Analysis of Simulation Models

    NARCIS (Netherlands)

    Kleijnen, J.P.C.

    2001-01-01

    This introductory tutorial gives a survey on the use of statistical designs for what if-or sensitivity analysis in simulation.This analysis uses regression analysis to approximate the input/output transformation that is implied by the simulation model; the resulting regression model is also known as

  19. Analysis of directional radiative behavior and heating efficiency for a gas-fired radiant burner

    International Nuclear Information System (INIS)

    Li, B.X.; Lu, Y.P.; Liu, L.H.; Kudo, K.; Tan, H.P.

    2005-01-01

    For the purpose of energy conservation and uniform heating of object surface, a gas-fired porous radiant burner with a bundle of reflecting tubes is developed. A physical model is developed to simulate the directional radiative behavior of this heating device, in which the Monte Carlo method based on the concept of radiation distribution factor is used to compute the directional radiative behavior. The effects of relating parameters on the directional behavior of radiative heating and the heating efficiency are analyzed. With the increase of the length-to-radius ratio of tube, the radiation heating efficiency decreases, but the radiation energy incident on the object surface is more collimated. The radiation heating efficiency increases with the specular reflectivity. With the increase in length of tube segment with specular reflective surface, the radiation heating efficiency increases, but the extent of concentration and collimation of radiative energy decreases. For real design of the heating device, some trade-offs are needed to balance the radiation heating efficiency and the uniformity of radiative heating of object surface

  20. Ecological Impacts of the Cerro Grande Fire: Predicting Elk Movement and Distribution Patterns in Response to Vegetative Recovery through Simulation Modeling October 2005

    Energy Technology Data Exchange (ETDEWEB)

    Rupp, Susan P. [Texas Tech Univ., Lubbock, TX (United States)

    2005-10-01

    In May 2000, the Cerro Grande Fire burned approximately 17,200 ha in north-central New Mexico as the result of an escaped prescribed burn initiated by Bandelier National Monument. The interaction of large-scale fires, vegetation, and elk is an important management issue, but few studies have addressed the ecological implications of vegetative succession and landscape heterogeneity on ungulate populations following large-scale disturbance events. Primary objectives of this research were to identify elk movement pathways on local and landscape scales, to determine environmental factors that influence elk movement, and to evaluate movement and distribution patterns in relation to spatial and temporal aspects of the Cerro Grande Fire. Data collection and assimilation reflect the collaborative efforts of National Park Service, U.S. Forest Service, and Department of Energy (Los Alamos National Laboratory) personnel. Geographic positioning system (GPS) collars were used to track 54 elk over a period of 3+ years and locational data were incorporated into a multi-layered geographic information system (GIS) for analysis. Preliminary tests of GPS collar accuracy indicated a strong effect of 2D fixes on position acquisition rates (PARs) depending on time of day and season of year. Slope, aspect, elevation, and land cover type affected dilution of precision (DOP) values for both 2D and 3D fixes, although significant relationships varied from positive to negative making it difficult to delineate the mechanism behind significant responses. Two-dimensional fixes accounted for 34% of all successfully acquired locations and may affect results in which those data were used. Overall position acquisition rate was 93.3% and mean DOP values were consistently in the range of 4.0 to 6.0 leading to the conclusion collar accuracy was acceptable for modeling purposes. SAVANNA, a spatially explicit, process-oriented ecosystem model, was used to simulate successional dynamics. Inputs to the

  1. Using small-scale rainfall simulation to assess temporal changes in pre- and post-fire soil hydrology and erosion: the value of fixed-position plots

    Science.gov (United States)

    Ferreira, Carla S. S.; Shakesby, Rick A.; Bento, Célia P. M.; Walsh, Rory P. D.; Ferreira, António J. D.

    2013-04-01

    In recent decades, wildfire has become both frequent and severe in southern Europe leading to widespread research into its impacts on soil erosion, soil and water quality. Rainfall simulation has become established as a popular technique to assess these impacts, as it can be conducted under controlled conditions (notably, with respect to rainfall) and is a very cost-effective and rapid way to compare overland flow and suspended sediment generation within burned and unburned sites. Particular advantages are that: (1) results can be obtained before the first post-fire rainfall events; and (2) experiments can reproduce controlled storm events, with similar characteristics to natural rain. Although plot sizes vary (0.09-30m2), most researchers have used removal of plot boundaries between surveys. This approach was tested over a 2.5-year period in a small (9 ha) catchment in central Portugal subjected to an experimental fire in 2009. Five rainfall simulation plots 0.25m2 in size were installed close to sediment traps (contributing areas: 498-4238m2) collecting sediment eroded by overland flow caused by natural rainfall. The plots were installed pre-fire and experiments carried out under 'dry' and 'wet' antecedent conditions on six occasions from pre-fire to two years after the fire. The lateral boundaries of each plot were left in place, but the upslope boundary and central (outlet) section of the downslope boundary were removed between surveys and re-installed and sealed each time measurements were carried out. Having fixed positions of plots minimised soil disturbance on each monitoring occasion and meant that, for any given plot, results were directly comparable and gave a more reliable picture of change through time. Removing the upper and lower boundaries of the plots between measurements allowed the soil to undergo processes similar to those on the surrounding slope and reduced the 'island' effect associated with continuously bounded plots. Results from the

  2. Simulation analysis of wastes gasification technologies

    Directory of Open Access Journals (Sweden)

    Stępień Leszek

    2017-01-01

    Full Text Available Each year a significant growth in the amount of wastes generated is observed. Due to this fact technologies enabling utilization of wastes are needed. One of the ways to utilizes wastes is thermal conversion. Most widely used technology for thermal conversion is gasification that enables to produce syngas that can be either combusted or directed to further synthesis to produce methanol or liquid fuels. There are several commercially available technologies that enable to gasify wastes. The first part of this study is subjected to general description of waste gasification process. Furthermore the analysis and comparison of commercially available gasification technologies is presented, including their process arrangement, limits and capabilities. Second part of the study is dedicated to the development of thermodynamic model for waste gasification. The model includes three zones of gasification reactors: drying, gasification and eventually ash melting. Modified Gibbs minimization method is used to simulate gasification process. The model is capable of predicting final gas composition as a function of temperature or equivalence ratio. Calculations are performed for a specified average wastes composition and different equivalence ratios of air to discuss its influence on the performance of gasification (temperature of the process and gas composition. Finally the model enables to calculate total energy balance of the process as well as gasification and final gas temperature.

  3. A Simulation Study on the Effects of Dendritic Morphology on Layer V Prefontal Pyramidal Cell Firing Behavior

    Directory of Open Access Journals (Sweden)

    Maria ePsarrou

    2014-09-01

    Full Text Available Pyramidal cells, the most abundant neurons in neocortex, exhibit significant structural variability across different brain areas and layers in different species. Moreover, in response to a somatic step current, these cells display a range of firing behaviors, the most common being (1 repetitive action potentials (Regular Spiking - RS, and (2 an initial cluster of 2-5 action potentials with short ISIs followed by single spikes (Intrinsic Bursting - IB. A correlation between firing behavior and dendritic morphology has recently been reported. In this work we use computational modeling to investigate quantitatively the effects of the basal dendritic tree morphology on the firing behavior of 112 three-dimensional reconstructions of layer V PFC rat pyramidal cells. Particularly, we focus on how different morphological (diameter, total length, volume and branch number and passive (Mean Electrotonic Path length features of basal dendritic trees shape somatic firing when the spatial distribution of ionic mechanisms in the basal dendritic trees is uniform or non-uniform. Our results suggest that total length, volume and branch number are the best morphological parameters to discriminate the cells as RS or IB, regardless of the distribution of ionic mechanisms in basal trees. The discriminatory power of total length, volume and branch number remains high in the presence of different apical dendrites. These results suggest that morphological variations in the basal dendritic trees of layer V pyramidal neurons in the PFC influence their firing patterns in a predictive manner and may in turn influence the information processing capabilities of these neurons.

  4. Cost analysis of a coal-fired power plant using the NPV method

    Science.gov (United States)

    Kumar, Ravinder; Sharma, Avdhesh Kr.; Tewari, P. C.

    2015-06-01

    The present study investigates the impact of various factors affecting coal-fired power plant economics of 210 MW subcritical unit situated in north India for electricity generation. In this paper, the cost data of various units of thermal power plant in terms of power output capacity have been fitted using power law with the help of the data collected from a literature search. To have a realistic estimate of primary components or equipment, it is necessary to include the latest cost of these components. The cost analysis of the plant was carried out on the basis of total capital investment, operating cost and revenue. The total capital investment includes the total direct plant cost and total indirect plant cost. Total direct plant cost involves the cost of equipment (i.e. boiler, steam turbine, condenser, generator and auxiliary equipment including condensate extraction pump, feed water pump, etc.) and other costs associated with piping, electrical, civil works, direct installation cost, auxiliary services, instrumentation and controls, and site preparation. The total indirect plant cost includes the cost of engineering and set-up. The net present value method was adopted for the present study. The work presented in this paper is an endeavour to study the influence of some of the important parameters on the lifetime costs of a coal-fired power plant. For this purpose, parametric study with and without escalation rates for a period of 35 years plant life was evaluated. The results predicted that plant life, interest rate and the escalation rate were observed to be very sensitive on plant economics in comparison to other factors under study.

  5. Release of radioactive materials in simulation test of a postulated solvent fire in a nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Nishio, G.; Hashimoto, K.

    1989-01-01

    This paper reports on small- and large-scale fire tests performed to examine the adequacy of a safety evaluation method for a solvent fire in the extraction process of a nuclear fuel reprocessing plant. The test objectives were to obtain information on the confinement of radioactive materials during a 30% tri-n-butyl phosphate-n-dodecane fire while air ventilation is operating in the cell. The rates of release of cesium, strontium, cerium, ruthenium, and uranium from a burning solvent were determined. The quantities of species released were obtained from the solvent burning rate, smoke generation rate, partition coefficients of species between solvent and water, and coefficients of species entrainment to atmosphere in cell

  6. A spatio-temporal analysis of fire recurrence and extent for semi-arid savanna ecosystems in Southern Africa using moderate-resolution satellite imagery.

    Science.gov (United States)

    Pricope, Narcisa G; Binford, Michael W

    2012-06-15

    Savanna ecosystems are semi-arid and fire-prone. Increasing temperatures and decreasing precipitation in Southern Africa will probably have a series of strong impacts on the various components of fire regimes in these ecosystems that will, in turn, affect their ecology, structure, and function. This paper presents a geospatial analysis to quantify changes in fire frequency, seasonality and spatial distribution during the last decade and creates a fire return interval map for the core area of the Kavango-Zambezi Transfrontier Conservation Area, which spans five Southern African countries and is the largest cooperative multistate conservation region in the world. To disentangle the relative contribution of environmental variability from country-specific land management decisions in driving changes in fire regimes, we use two different products from the MODIS Terra platform (Active Fire and Burned Area products), TRMM precipitation data and the Multivariate ENSO Index data to analyze change in fire regimes among the five countries, differentiating between different land uses such as protected areas, forest reserves, and communal lands and accounting for specific changes in fire management policies. There are significant differences in fire frequencies between countries with more effective fire management (Botswana and Zimbabwe) and countries where anthropogenic, mainly early-dry season, burning is largely uncontrolled (Namibia, Angola, and Zambia), both within and outside protected areas, while all countries and land-use units show an overall increasing trend in fire occurrences. Large fire occurrences increased up to 200% in the period before the beginning of the natural fire season in Namibia, where a new prescribed burn policy was introduced in 2006, while the other countries show a slightly different shift in seasonality of increasing fire occurrences mainly during the dry season. The mean size of fires also increases significantly across all land uses despite

  7. Mechanical Analysis of an SM 2 Blk IV restrained firing within a concentric canister launcher test unit; TOPICAL

    International Nuclear Information System (INIS)

    Kassner, M C; Kennedy, T C; Puttapitukporn, T; Rosen, R S

    1999-01-01

    The Office of Naval Research (ONR) and PMS512 have undertaken a program to develop a new Vertical Launching System (VLS) for future generation ships, such as the DD-21 Destroyer. The Naval Sea Systems Command Combat Weapons Program (NAVSEA 05K) and Naval Surface Warfare Center Dahlgren Division (NSWCDD) are working jointly with industry and universities to develop one such launcher design, the Concentric Canister Launcher (CCL). The basic CCL design consists of a tube made of two concentric cylinders; one end is open, the other is sealed with a hemispherical end cap. During firing, the missile exhaust gas is turned 180 degrees by the hemispherical end cap and flows through the annular space between inner and outer cylinders. Depending on the missile utilized and the particular service environment of the CCL, maximum temperatures within the cylinder material have been calculated to exceed 2000 F. In an earlier study[1], the authors determined the high temperature mechanical properties of several candidate alloys being considered for fabrication of the CCL. This study[1] found that, of these candidate materials, titanium alloys exhibit higher yield stresses than that of 316L stainless steel at temperatures up to about 1000 F; above 1500 F, the yield stress of 316L stainless steel is comparable to those of the titanium alloys. The 316L stainless steel was found to strain harden (increase its flow stress with increasing strain) at temperatures up to about 1800 F. The ability of the 316L stainless steel to strain harden at high temperatures may provide an added margin of safety for engineering design of the CCL. The objective of the current study was to perform a computer simulation of the structural response of a CCL during a restrained firing, one in which a SM-2 Blk IV missile would fail to exit the canister. A finite element model of the inner cylinder, outer cylinder, end rings (mounting brackets), and lateral restraints in the uptake was constructed. An elastic

  8. A multivariate decision tree analysis of biophysical factors in tropical forest fire occurrence

    Science.gov (United States)

    Rey S. Ofren; Edward Harvey

    2000-01-01

    A multivariate decision tree model was used to quantify the relative importance of complex hierarchical relationships between biophysical variables and the occurrence of tropical forest fires. The study site is the Huai Kha Kbaeng wildlife sanctuary, a World Heritage Site in northwestern Thailand where annual fires are common and particularly destructive. Thematic...

  9. How knowledge influences a MCDM analysis: WOCAT Portuguese experience on prevention of forest fires

    Science.gov (United States)

    Carreiras, M.; Ferreira, A. J. D.; Moreira, J.; Esteves, T. C. J.; Valente, S.; Soares, J.; Coelho, C. O. A.; Schwilch, G.; Bachmann, F.

    2012-04-01

    degradation processes. Affecting large areas every year, they also have serious human, socio-economic and psychological impacts. Under the DESIRE project two Portuguese study sites were selected - Góis e Mação. Both study sites are located in Central Portugal and are frequently affected by forest fires. Nowadays different types of solutions applied at the local level are related with the prevention, combat and mitigation of forest fires. At a higher level of analysis the main solution is related with the diversification of the soil uses, mainly by the mixture of cropland, pastures and forest areas. But the selection of the technique isn't so far an open, participative and effective process, and the interests of land users are not represented most of the time. This paper aims to present WOCAT approach and results to forest fire prevention in Portugal considering stakeholder's perspectives and policy recommendations and it's evolution based on an increased of knowledge.

  10. The vulcain N expert fire system

    International Nuclear Information System (INIS)

    Roche, A.

    1989-03-01

    The Institute for Nuclear Safety and Protection (IPSN) has begun work on an expert system to aid in the diagnosis of fire hazards in nuclear installations. This system is called Vulcain N and is designed as a support tool for the analyses carried out by the IPSN. Vulcain N, is based on the Vulcain expert system already developed by Bertin for its own needs and incorporates the specific rules and know-how of the IPSN experts. The development of Vulcain N began in October 1986 with the drawing up of the technical specifications, and should be completed by the end of 1988. Vulcain N brings together knowledge from a number of different domains: the locations of the combustible materials, the thermal characteristics of the combustible materials and of the walls of the room, the ventilation conditions and, finally, knowledge of fire experts concerning the development of fire. The latter covers four levels of expert knowledge: standards and their associated calculations, the simplified physics of the fire enabling more precise values to be obtained for the figures given by the standards, the rules and knowledge which enables a certain number of deductions to be made concerning the development of the fire, and a numerical simulation code which can be used to monitor the variation of certain characteristic parameters with time. For a given fire out-break scenario, Vulcain N performs diagnosis of different aspects: development of fire, effect of ventilation, emergency action possibilities, propagation hazards, etc. Owing to its flexibility, it can be used in the analysis of fire hazards to simulate a number of possible scenarios and to very rapidly deduce the essential, predominant factors. It will also be used to assist in drafting emergency procedures for application in facilities with nuclear hazards

  11. Effect of ice-quenching on the change in hardness of a Pd-Au-Zn alloy during porcelain firing simulation.

    Science.gov (United States)

    Shin, Hye-Jeong; Kim, Min-Jung; Kim, Hyung-Il; Kwon, Yong Hoon; Seol, Hyo-Joung

    2017-03-31

    This study examined the effect of ice-quenching after degassing on the change in hardness of a Pd-Au-Zn alloy during porcelain firing simulations. By ice-quenching after degassing, the specimens were softened due to homogenization without the need for an additional softening heat treatment. The lowered hardness by ice-quenching after degassing was recovered greatly from the first stage of porcelain firing process by controlling the cooling rate. The increase in hardness during cooling after porcelain firing was attributed to the precipitation of the f.c.t. PdZn phase containing Au, which caused severe lattice strain in the interphase boundary between the precipitates and matrix of the f.c.c. structure. The final hardness was slightly higher in the ice-quenched specimen than in the specimen cooled at stage 0 (the most effective cooling rate for alloy hardening) after degassing. This was attributed to the more active grain interior precipitation during cooling in the ice-quenched specimen after degassing.

  12. Analysis and simulation of Wiseman hypocycloid engine

    Directory of Open Access Journals (Sweden)

    Priyesh Ray

    2014-12-01

    Full Text Available This research studies an alternative to the slider-crank mechanism for internal combustion engines, which was proposed by the Wiseman Technologies Inc. Their design involved replacing the crankshaft with a hypocycloid gear assembly. The unique hypocycloid gear arrangement allowed the piston and connecting rod to move in a straight line creating a perfect sinusoidal motion, without any side loads. In this work, the Wiseman hypocycloid engine was modeled in a commercial engine simulation software and compared to slider-crank engine of the same size. The engine’s performance was studied, while operating on diesel, ethanol, and gasoline fuel. Furthermore, a scaling analysis on the Wiseman engine prototypes was carried out to understand how the performance of the engine is affected by increasing the output power and cylinder displacement. It was found that the existing 30cc Wiseman engine produced about 7% less power at peak speeds than the slider-crank engine of the same size. These results were concurrent with the dynamometer tests performed in the past. It also produced lower torque and was about 6% less fuel efficient than the slider-crank engine. The four-stroke diesel variant of the same Wiseman engine performed better than the two-stroke gasoline version. The Wiseman engine with a contra piston (that allowed to vary the compression ratio showed poor fuel efficiency but produced higher torque when operating on E85 fuel. It also produced about 1.4% more power than while running on gasoline. While analyzing effects of the engine size on the Wiseman hypocycloid engine prototypes, it was found that the engines performed better in terms of power, torque, fuel efficiency, and cylinder brake mean effective pressure as the displacement increased. The 30 horsepower (HP conceptual Wiseman prototype, while operating on E85, produced the most optimum results in all aspects, and the diesel test for the same engine proved to be the most fuel efficient.

  13. FDTD simulation tools for UWB antenna analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2004-12-01

    This paper describes the development of a set of software tools useful for analyzing ultra-wideband (UWB) antennas and structures. These tools are used to perform finite difference time domain (FDTD) simulation of a conical antenna with continuous wave (CW) and UWB pulsed excitations. The antenna is analyzed using spherical coordinate-based FDTD equations that are derived from first principles. The simulation results for CW excitation are compared to simulation and measured results from published sources; the results for UWB excitation are new.

  14. FDTD simulation tools for UWB antenna analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2005-02-01

    This paper describes the development of a set of software tools useful for analyzing ultra-wideband (UWB) antennas and structures. These tools are used to perform finite difference time domain (FDTD) simulation of a conical antenna with continuous wave (CW) and UWB pulsed excitations. The antenna is analyzed using spherical coordinate-based FDTD equations that are derived from first principles. The simulation results for CW excitation are compared to simulation and measured results from published sources; the results for UWB excitation are new.

  15. Failure Analysis and Magnetic Evaluation of Tertiary Superheater Tube Used in Gas-Fired Boiler

    Science.gov (United States)

    Mohapatra, J. N.; Patil, Sujay; Sah, Rameshwar; Krishna, P. C.; Eswarappa, B.

    2018-01-01

    Failure analysis was carried out on a prematurely failed tertiary superheater tube used in gas-fired boiler. The analysis includes a comparative study of visual examination, chemical composition, hardness and microstructure at failed region, adjacent and far to failure as well as on fresh tube. The chemistry was found matching to the standard specification, whereas the hardness was low in failed tube compared to the fish mouth opening region and the fresh tube. Microscopic examination of failed sample revealed the presence of spheroidal carbides of Cr and Mo predominantly along the grain boundaries. The primary cause of failure is found to be localized heating. Magnetic hysteresis loop (MHL) measurements were carried out to correlate the magnetic parameters with microstructure and mechanical properties to establish a possible non-destructive evaluation (NDE) for health monitoring of the tubes. The coercivity of the MHL showed a very good correlation with microstructure and mechanical properties deterioration enabling a possible NDE technique for the health monitoring of the tubes.

  16. Failure Analysis and Magnetic Evaluation of Tertiary Superheater Tube Used in Gas-Fired Boiler

    Science.gov (United States)

    Mohapatra, J. N.; Patil, Sujay; Sah, Rameshwar; Krishna, P. C.; Eswarappa, B.

    2018-02-01

    Failure analysis was carried out on a prematurely failed tertiary superheater tube used in gas-fired boiler. The analysis includes a comparative study of visual examination, chemical composition, hardness and microstructure at failed region, adjacent and far to failure as well as on fresh tube. The chemistry was found matching to the standard specification, whereas the hardness was low in failed tube compared to the fish mouth opening region and the fresh tube. Microscopic examination of failed sample revealed the presence of spheroidal carbides of Cr and Mo predominantly along the grain boundaries. The primary cause of failure is found to be localized heating. Magnetic hysteresis loop (MHL) measurements were carried out to correlate the magnetic parameters with microstructure and mechanical properties to establish a possible non-destructive evaluation (NDE) for health monitoring of the tubes. The coercivity of the MHL showed a very good correlation with microstructure and mechanical properties deterioration enabling a possible NDE technique for the health monitoring of the tubes.

  17. Modern analysis of ion channeling data by Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Nowicki, Lech [Andrzej SoItan Institute for Nuclear Studies, ul. Hoza 69, 00-681 Warsaw (Poland)]. E-mail: lech.nowicki@fuw.edu.pl; Turos, Andrzej [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Ratajczak, Renata [Andrzej SoItan Institute for Nuclear Studies, ul. Hoza 69, 00-681 Warsaw (Poland); Stonert, Anna [Andrzej SoItan Institute for Nuclear Studies, ul. Hoza 69, 00-681 Warsaw (Poland); Garrido, Frederico [Centre de Spectrometrie Nucleaire et Spectrometrie de Masse, CNRS-IN2P3-Universite Paris-Sud, 91405 Orsay (France)

    2005-10-15

    Basic scheme of ion channeling spectra Monte Carlo simulation is reformulated in terms of statistical sampling. The McChasy simulation code is described and two examples of the code applications are presented. These are: calculation of projectile flux in uranium dioxide crystal and defect analysis for ion implanted InGaAsP/InP superlattice. Virtues and pitfalls of defect analysis using Monte Carlo simulations are discussed.

  18. Using simulated 3D surface fuelbeds and terrestrial laser scan data to develop inputs to fire behavior models

    Science.gov (United States)

    Eric Rowell; E. Louise Loudermilk; Carl Seielstad; Joseph O' Brien

    2016-01-01

    Understanding fine-scale variability in understory fuels is increasingly important as physics-based fire behavior modelsdrive needs for higher-resolution data. Describing fuelbeds 3Dly is critical in determining vertical and horizontal distributions offuel elements and the mass, especially in frequently burned pine ecosystems where fine-scale...

  19. Image based SAR product simulation for analysis

    Science.gov (United States)

    Domik, G.; Leberl, F.

    1987-01-01

    SAR product simulation serves to predict SAR image gray values for various flight paths. Input typically consists of a digital elevation model and backscatter curves. A new method is described of product simulation that employs also a real SAR input image for image simulation. This can be denoted as 'image-based simulation'. Different methods to perform this SAR prediction are presented and advantages and disadvantages discussed. Ascending and descending orbit images from NASA's SIR-B experiment were used for verification of the concept: input images from ascending orbits were converted into images from a descending orbit; the results are compared to the available real imagery to verify that the prediction technique produces meaningful image data.

  20. Uncertainty analysis of steady state incident heat flux measurements in hydrocarbon fuel fires.

    Energy Technology Data Exchange (ETDEWEB)

    Nakos, James Thomas

    2005-12-01

    The objective of this report is to develop uncertainty estimates for three heat flux measurement techniques used for the measurement of incident heat flux in a combined radiative and convective environment. This is related to the measurement of heat flux to objects placed inside hydrocarbon fuel (diesel, JP-8 jet fuel) fires, which is very difficult to make accurately (e.g., less than 10%). Three methods will be discussed: a Schmidt-Boelter heat flux gage; a calorimeter and inverse heat conduction method; and a thin plate and energy balance method. Steady state uncertainties were estimated for two types of fires (i.e., calm wind and high winds) at three times (early in the fire, late in the fire, and at an intermediate time). Results showed a large uncertainty for all three methods. Typical uncertainties for a Schmidt-Boelter gage ranged from {+-}23% for high wind fires to {+-}39% for low wind fires. For the calorimeter/inverse method the uncertainties were {+-}25% to {+-}40%. The thin plate/energy balance method the uncertainties ranged from {+-}21% to {+-}42%. The 23-39% uncertainties for the Schmidt-Boelter gage are much larger than the quoted uncertainty for a radiative only environment (i.e ., {+-}3%). This large difference is due to the convective contribution and because the gage sensitivities to radiative and convective environments are not equal. All these values are larger than desired, which suggests the need for improvements in heat flux measurements in fires.

  1. The use of vapour phase ultra-violet spectroscopy for the analysis of arson accelerants in fire scene debris.

    Science.gov (United States)

    McCurdy, R J; Atwell, T; Cole, M D

    2001-12-01

    A method has been developed for the analysis of arson accelerants in fire scene debris by vapour phase ultra-violet (UV) spectroscopy. The method is rapid, inexpensive, simple to use and is sufficiently sensitive and discriminating to be of use for the analysis of crime scene samples. Application to casework samples is described. On occasion, the method offers additional information to that which can be obtained by gas chromatography-flame ionisation detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS) and represents a useful adjunct to these techniques. In addition, the method offers advantages where the use of GC-MS analysis of arson accelerants in fire scene debris is not a practical proposition.

  2. Aircraft vulnerability analysis by modeling and simulation

    Science.gov (United States)

    Willers, Cornelius J.; Willers, Maria S.; de Waal, Alta

    2014-10-01

    Infrared missiles pose a significant threat to civilian and military aviation. ManPADS missiles are especially dangerous in the hands of rogue and undisciplined forces. Yet, not all the launched missiles hit their targets; the miss being either attributable to misuse of the weapon or to missile performance restrictions. This paper analyses some of the factors affecting aircraft vulnerability and demonstrates a structured analysis of the risk and aircraft vulnerability problem. The aircraft-missile engagement is a complex series of events, many of which are only partially understood. Aircraft and missile designers focus on the optimal design and performance of their respective systems, often testing only in a limited set of scenarios. Most missiles react to the contrast intensity, but the variability of the background is rarely considered. Finally, the vulnerability of the aircraft depends jointly on the missile's performance and the doctrine governing the missile's launch. These factors are considered in a holistic investigation. The view direction, altitude, time of day, sun position, latitude/longitude and terrain determine the background against which the aircraft is observed. Especially high gradients in sky radiance occur around the sun and on the horizon. This paper considers uncluttered background scenes (uniform terrain and clear sky) and presents examples of background radiance at all view angles across a sphere around the sensor. A detailed geometrical and spatially distributed radiometric model is used to model the aircraft. This model provides the signature at all possible view angles across the sphere around the aircraft. The signature is determined in absolute terms (no background) and in contrast terms (with background). It is shown that the background significantly affects the contrast signature as observed by the missile sensor. A simplified missile model is constructed by defining the thrust and mass profiles, maximum seeker tracking rate, maximum

  3. Thermal surface characteristics of coal fires 1 results of in-situ measurements

    Science.gov (United States)

    Zhang, Jianzhong; Kuenzer, Claudia

    2007-12-01

    . Thus, night-time analysis is the most suitable for thermal anomaly mapping of underground coal fires, although this is not always feasible. The heat of underground coal fires only progresses very slowly through conduction in the rock material. Anomalies of coal fires completely covered by solid unfractured bedrock are very weak and were only measured during the night. The thermal pattern of underground coal fires manifested on the surface during the daytime is thus the pattern of cracks and vents, which occur due to the volume loss underground and which support radiation and convective energy transport of hot gasses. Inside coal fire temperatures can hardly be measured and can only be recorded if the glowing coal is exposed through a wider crack in the overlaying bedrock. Direct coal fire temperatures measured ranged between 233 °C and 854 °C. The results presented can substantially support the planning of thermal mapping campaigns, analyses of coal fire thermal anomalies in remotely sensed data, and can provide initial and boundary conditions for coal fire related numerical modeling. In a second paper named "Thermal Characteristics of Coal Fires 2: results of measurements on simulated coal fires" [ Zhang J., Kuenzer C., Tetzlaff A., Oettl D., Zhukov B., Wagner W., 2007. Thermal Characteristics of Coal Fires 2: Result of measurements on simulated coal fires. Accepted for publication at Journal of Applied Geophysics. doi:10.1016/j.jappgeo.2007.08.003] we report about thermal characteristics of simulated coal fires simulated under simplified conditions. The simulated set up allowed us to measure even more parameters under undisturbed conditions — especially inside fire temperatures. Furthermore we could demonstrate the differences between open surface coal fires and covered underground coal fires. Thermal signals of coal fires in near range thermal remotely sensed imagery from an observing tower and from an airplane are presented and discussed.

  4. FIRE PROTECTION SYSTEMS AND TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Aristov Denis Ivanovich

    2016-03-01

    Full Text Available The All-Russian Congress “Fire Stop Moscow” was de-voted to the analysis of the four segments of the industry of fire protection systems and technologies: the design of fire protec-tion systems, the latest developments and technologies of active and passive fire protection of buildings, the state and the devel-opment of the legal framework, the practice of fire protection of buildings and structures. The forum brought together the repre-sentatives of the industry of fire protection systems, scientists, leading experts, specialists in fire protection and representatives of construction companies from different regions of Russia. In parallel with the Congress Industrial Exhibition of fire protection systems, materials and technology was held, where manufacturers presented their products. The urgency of the “Fire Stop Moscow” Congress in 2015 organized by the Congress Bureau ODF Events lies primarily in the fact that it considered the full range of issues related to the fire protection of building and construction projects; studied the state of the regulatory framework for fire safety and efficiency of public services, research centers, private companies and busi-nesses in the area of fire safety. The main practical significance of the event which was widely covered in the media space, was the opportunity to share the views and information between management, science, and practice of business on implementing fire protection systems in the conditions of modern economic relations and market realities. : congress, fire protection, systems, technologies, fire protection systems, exhibition

  5. HAZARDS OF THERMAL EXPANSION FOR RADIOLOGICAL CONTAINER ENGULFED IN FIRE

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen

    2013-05-01

    Fire accidents pose a serious threat to nuclear facilities. It is imperative that transport casks or shielded containers designed to transport/contain radiological materials have the ability to withstand a hypothetical fire. A numerical simulation was performed for a shielded container constructed of stainless steel and lead engulfed in a hypothetical fire as outlined by 10 CFR §71.73. The purpose of this analysis was to determine the thermal response of the container during and after the fire. The thermal model shows that after 30 minutes of fire, the stainless steel will maintain its integrity and not melt. However, the lead shielding will melt since its temperature exceeds the melting point. Due to the method of construction of the container under consideration, ample void space must be provided to allow for thermal expansion of the lead upon heating and melting, so as to not overstress the weldment.

  6. Psychological sequelae of the station nightclub fire: Comparing survivors with and without physical injuries using a mixed-methods analysis.

    Directory of Open Access Journals (Sweden)

    Nhi-Ha T Trinh

    Full Text Available Surveying survivors from a large fire provides an opportunity to explore the impact of emotional trauma on psychological outcomes.This is a cross-sectional survey of survivors of The Station Fire. Primary outcomes were post-traumatic stress (Impact of Event Scale - Revised and depressive (Beck Depression Inventory symptoms. Linear regression was used to examine differences in symptom profiles between those with and without physical injuries. The free-response section of the survey was analyzed qualitatively to compare psychological sequelae of survivors with and without physical injuries.104 participants completed the study survey; 47% experienced a burn injury. There was a 42% to 72% response rate range. The mean age of respondents was 32 years, 62% were male, and 47% experienced a physical injury. No significant relationships were found between physical injury and depressive or post-traumatic stress symptom profiles. In the qualitative analysis, the emotional trauma that survivors experienced was a major, common theme regardless of physical injury. Survivors without physical injuries were more likely to experience survivor guilt, helplessness, self-blame, and bitterness. Despite the post-fire challenges described, most survivors wrote about themes of recovery and renewal.All survivors of this large fire experienced significant psychological sequelae. These findings reinforce the importance of mental health care for all survivors and suggest a need to understand factors influencing positive outcomes.

  7. Using a model based fourth-corner analysis to explain vegetation change following an extraordinary fire disturbance.

    Science.gov (United States)

    Venn, S E; Pickering, C M; Butler, S A; Letten, A D

    2016-11-01

    In ecosystems where large-scale disturbances are infrequent, the mode of succession may be difficult to discern and floristic surveys alone cannot be used determine the underlying processes causing vegetation change. To determine the causes of vegetation change in response to a large-scale fire event, we combined traditional floristic survey data, plant functional traits and environmental variables in a model-based solution to the fourth-corner problem. This approach allowed us to describe the trait-environment relationship and provides an intuitive matrix of environment by trait interaction coefficients. We could then quantify the strength and direction of associations between plant traits, species life-forms and environmental factors in two alpine plant communities over nine years post-fire. Initially, the fire drastically reduced vegetation cover and species density to very low levels. The fourth-corner analysis interaction coefficients indicated that over the course of the nine-year study a high abundance of graminoids, a low abundance of shrubs, tall species and those with high leaf dry matter content had the strongest associations with the two plant communities. We also found evidence for functional homogenisation between these two communities using this novel technique. Analysing plant traits and species responses post-fire in this manner can be used to infer the ecological processes driving shifts in vegetation.

  8. Macrocharcoal analysis of a 4200 year old lake sediment profile from Northern Romania - fire regimes and climate implications

    Directory of Open Access Journals (Sweden)

    Anca GEANTĂ

    2014-11-01

    Full Text Available Macroscopic charcoal particles, magnetic susceptibility and AMS C14 dates were performed on a sediment sequence from a small subalpine lake (Buhaescu Mare, Rodnei Mts. in order to reconstruct fire regimes in the area.  Specifically we aim to distinguish between natural fire activity and human driven fires. Buhaescu Mare lake, also known as Rebra lake (0.4 ha; 1920 m a.s.l., is today surrounded by mire vegetation, Ericaceae, Carex and Pinus mugo patches further away, being situated just above the current tree line. The sedimentary profile, with a total length of 98 cm is composed of clayey silt (98-80 cm and gyttja (80-0 cm. Magnetic susceptibility was used to support the charcoal results, this parameter being expected to rise during episodes of intense fire and subsequent erosive events.The results from the charcoal record indicate periods of high charcoal activity at about 4200 cal. BP, 3000 cal. BP, 2700 cal BP, 2000 cal BP and 1350 cal BP. and point to a succession of warm/dry and cold/wet periods. The increase in charcoal particles over the last 2000 years was probably related to human impact, but this remains to be documented through the analysis of pollen and coprophilous fungi record.

  9. Fire safety engineering

    International Nuclear Information System (INIS)

    Smith, D.N.

    1989-01-01

    The periodic occurrence of large-scale, potentially disastrous industrial accidents involving fire in hazardous environments such as oilwell blowouts, petrochemical explosions and nuclear installations highlights the need for an integrated approach to fire safety engineering. Risk reduction 'by design' and rapid response are of equal importance in the saving of life and property in such situations. This volume of papers covers the subject thoroughly, touching on such topics as hazard analysis, safety design and testing, fire detection and control, and includes studies of fire hazard in the context of environment protection. (author)

  10. Using a stochastic model and cross-scale analysis to evaluate controls on historical low-severity fire regimes

    Science.gov (United States)

    Maureen C. Kennedy; Donald. McKenzie

    2010-01-01

    Fire-scarred trees provide a deep temporal record of historical fire activity, but identifying the mechanisms therein that controlled landscape fire patterns is not straightforward. We use a spatially correlated metric for fire co-occurrence between pairs of trees (the Sørensen distance variogram), with output from a neutral model for fire history, to infer the...

  11. A study of the evolution of rust on Mo–Cu-bearing fire-resistant steel submitted to simulated atmospheric corrosion

    International Nuclear Information System (INIS)

    Hao Long; Zhang Sixun; Dong Junhua; Ke Wei

    2012-01-01

    Highlights: ► The rusting evolution of a Mo–Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated. ► The rusting evolution of the steel is related to the rust composition, structure, and electrochemical characteristics. ► Increased content of α-FeOOH and decreased γ-FeOOH and Fe 3 O 4 indicate the enhanced resistance of the rust. ► Mo and Cu are involved in the formation of molybdate and Cu(I)-bearing compounds in the rust. - Abstract: The corrosion evolution of a Mo–Cu-bearing fire-resistant steel in a simulated industrial atmosphere was investigated by corrosion weight gain, XRD, EPMA, XPS, and polarization curves. The results indicate that the corrosion kinetics is closely related to the rust composition and electrochemical properties. As the corrosion proceeds, the relative content of γ-FeOOH and Fe 3 O 4 decreases and α-FeOOH increases, and the rust layer becomes compact and adherent to steel substrate. Molybdenum and copper enrich in the inner rust layer, especially at the bottom of the corrosion nest, forming non-soluble molybdate and Cu(I)-bearing compounds responsible for enhanced corrosion resistance of the rust layer.

  12. Treatment and Analysis of a Paint Chip from "Water Lilies": A Fire Damaged Monet

    Science.gov (United States)

    Miller, Sharon K. R.; Banks, Bruce A.; Tollis, Greg

    2001-01-01

    A museum fire in 1958 severely damaged a Monet 'Water Lilies' (1916-1926) painting that was on display. The surface of the painting is very dark with areas of blistering and charring. Over the years, traditional techniques have been found to be ineffective at removal of the soot and char from the surface. The painting, which is now in the care of the New York University (NYU) Conservation Center of the Institute of Fine Arts, was the subject of a study to determine if atomic oxygen treatment could remove the soot and char without damaging the fragile painting underneath. For test purposes, a small chip of paint was removed from the edge of the painting by a conservator at NYU and supplied to NASA Glenn Research Center for atomic oxygen treatment and analysis. The diffuse spectral reflectance, at three locations on the paint chip, was monitored at intervals during the atomic oxygen treatment process. Photo documentation of the chip during treatment was also performed. The color contrast was calculated from the spectral reflectance data as a function of treatment duration. Results of the testing indicated that the contrast improved as a result of the treatment, and the differentiation of colors on the surface was significantly improved. Soot and char could be removed without visibly affecting the gross surface features such as impasto areas. These results indicate the feasibility for the treatment of the 'Water Lilies' painting.

  13. Damage analysis of the forced draft fan blade in coal fired power plant

    Directory of Open Access Journals (Sweden)

    M. Nurbanasari

    2017-04-01

    Full Text Available The Forced Draft Fan (FDF blade in a 300 MW coal fired power plant that experienced catastrophic failure has been investigated. There were two main locations of the blade damage, namely damage at the root of the blade and the other one is at the third of the blade height. The FDF blade has been run for 5 years and before its failure, the FDF experienced high vibration (14 mm/s. The forced draft fan is an axial flow fan horizontally in front of the boiler and the fan is single stage. Visual inspection, metallographic analysis, chemical composition and hardness test were carried out to find the cause of the failure. It is concluded that the material of the blade is cast Al-Si alloy (A356.0 that fits the requirements for FDF blade application, the failure of the third of the blade height is owing to the external particles collide to the leading edge of the blades causing erosion and notch. That notch acted as initial crack. The failure at the root blade was caused by broken fragments of the others damaged blades entered in between casing (stator and the blade (rotor so they obstructed the blade rotation.

  14. Collection and analysis of training simulator data

    International Nuclear Information System (INIS)

    Krois, P.A.; Haas, P.M.

    1985-01-01

    The purposes of this paper are: (1) to review the objectives, approach, and results of a series of research experiments performed on nuclear power plant training simulators in support of regulatory and research programs of the US Nuclear Regulatory Commission (NRC), and (2) to identify general research issues that may lead to an improved research methodology using the training simulator as a field setting. Research products consist of a refined field research methodology, a data store on operator performance, and specific results pertinent to NRC regulatory positions. Issues and potential advances in operator performance measurement are discussed

  15. Socio-economic impact analysis: Centralia mine fire abatement alternatives. Draft report

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-07

    The overall purpose of information contained in the following text is to document the likely social and economic impacts upon the Borough of Centralia through implementation of various mine fire abatement alternatives. Much of the data presented herein and utilized in preparing conclusions and recommendations have been derived from those individuals whose lives are now, or may eventually be, impacted by the underground mine fire.

  16. Remote sensing analysis of vegetation recovery following short-interval fires in Southern California shrublands.

    Science.gov (United States)

    Meng, Ran; Dennison, Philip E; D'Antonio, Carla M; Moritz, Max A

    2014-01-01

    Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change. Short interval fires are widely considered to be detrimental to reestablishment of shrub species in southern California chaparral, facilitating the invasion of exotic annuals and producing "type conversion". However, supporting evidence for type conversion has largely been at local, site scales and over short post-fire time scales. Type conversion has not been shown to be persistent or widespread in chaparral, and past range improvement studies present evidence that chaparral type conversion may be difficult and a relatively rare phenomenon across the landscape. With the aid of remote sensing data covering coastal southern California and a historical wildfire dataset, the effects of short interval fires (fire history, climate and elevation) were analyzed by linear regression. Reduced vegetation cover was found in some lower elevation areas that were burned twice in short interval fires, where non-sprouting species are more common. However, extensive type conversion of chaparral to grassland was not evident in this study. Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery.

  17. Remote sensing analysis of vegetation recovery following short-interval fires in Southern California shrublands.

    Directory of Open Access Journals (Sweden)

    Ran Meng

    Full Text Available Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change. Short interval fires are widely considered to be detrimental to reestablishment of shrub species in southern California chaparral, facilitating the invasion of exotic annuals and producing "type conversion". However, supporting evidence for type conversion has largely been at local, site scales and over short post-fire time scales. Type conversion has not been shown to be persistent or widespread in chaparral, and past range improvement studies present evidence that chaparral type conversion may be difficult and a relatively rare phenomenon across the landscape. With the aid of remote sensing data covering coastal southern California and a historical wildfire dataset, the effects of short interval fires (<8 years on chaparral recovery were evaluated by comparing areas that burned twice to adjacent areas burned only once. Twelve pairs of once- and twice-burned areas were compared using normalized burn ratio (NBR distributions. Correlations between measures of recovery and explanatory factors (fire history, climate and elevation were analyzed by linear regression. Reduced vegetation cover was found in some lower elevation areas that were burned twice in short interval fires, where non-sprouting species are more common. However, extensive type conversion of chaparral to grassland was not evident in this study. Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery.

  18. Exergetic analysis of a steam power plant using coal and rice straw in a co-firing process

    Energy Technology Data Exchange (ETDEWEB)

    Restrepo, Alvaro; Miyake, Raphael Guardini; Bazzo, Edson [Federal University of Santa Catarina (UFSC), Dept. of Mechanical Engineering, Florianopolis, SC (Brazil)], e-mails: arestrep@labcet.ufsc.br, miyake@labcet.ufsc.br, ebazzo@emc.ufsc.br; Bzuneck, Marcelo [Tractebel Energia S.A., Capivari de Baixo, SC (Brazil). U.O. Usina Termeletrica Jorge Lacerda C.], e-mail: marcelob@tractebelenergia.com.br

    2010-07-01

    This paper presents an exergetic analysis concerning an existing 50 M We steam power plant, which operates with pulverized coal from Santa Catarina- Brazil. In this power plant, a co-firing rice straw is proposed, replacing up to 10% of the pulverized coal in energy basis required for the boiler. Rice straw has been widely regarded as an important source for bio-ethanol, animal feedstock and organic chemicals. The use of rice straw as energy source for electricity generation in a co-firing process with low rank coal represents a new application as well as a new challenge to overcome. Considering both scenarios, the change in the second law efficiency, exergy destruction, influence of the auxiliary equipment and the greenhouse gases emissions such as CO{sub 2} and SO{sub 2} were considered for analysis. (author)

  19. Modelling the role of fires in the terrestrial carbon balance by incorporating SPITFIRE into the global vegetation modelORCHIDEE - Part 1: Simulating historical global burned area and fire regimes

    Science.gov (United States)

    C. Yue; P. Ciais; P. Cadule; K. Thonicke; S. Archibald; B. Poulter; W. M. Hao; S. Hantson; F. Mouillot; P. Friedlingstein; F. Maignan; N. Viovy

    2014-01-01

    Fire is an important global ecological process that influences the distribution of biomes, with consequences for carbon, water, and energy budgets. Therefore it is impossible to appropriately model the history and future of the terrestrial ecosystems and the climate system without including fire. This study incorporates the process-based prognostic fire module SPITFIRE...

  20. Fire forum 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference contains 18 presentations on various aspects of fire prevention and protection within the power production plants and industry, safety of building constructions, cable and transformer problems, risk and safety evaluation methods, management aspects, relevant Norwegian and Icelandic laws and regulations and oil analysis. Some examples of fires and explosions are also presented. (tk)

  1. Mathematical analysis and simulation of crop micrometeorology

    NARCIS (Netherlands)

    Chen, J.

    1984-01-01

    In crop micrometeorology the transfer of radiation, momentum, heat and mass to or from a crop canopy is studied. Simulation models for these processes do exist but are not easy to handle because of their complexity and the long computing time they need. Moreover, up to now such models can

  2. Simulation and formal analysis of visual attention

    NARCIS (Netherlands)

    Bosse, T.; Maanen, P.P. van; Treur, J.

    2009-01-01

    In this paper a simulation model for visual attention is discussed and formally analysed. The model is part of the design of an agent-based system that supports a naval officer in its task to compile a tactical picture of the situation in the field. A case study is described in which the model is

  3. Fire protection

    International Nuclear Information System (INIS)

    Janetzky, E.

    1980-01-01

    Safety and fire prevention measurements have to be treated like the activities developing, planning, construction and erection. Therefore it is necessary that these measurements have to be integrated into the activities mentioned above at an early stage in order to guarantee their effectiveness. With regard to fire accidents the statistics of the insurance companies concerned show that the damage caused increased in the last years mainly due to high concentration of material. Organization of fire prevention and fire fighting, reasons of fire break out, characteristics and behaviour of fire, smoke and fire detection, smoke and heat venting, fire extinguishers (portable and stationary), construction material in presence of fire, respiratory protection etc. will be discussed. (orig./RW)

  4. A data envelopment analysis for energy efficiency of coal-fired power units in China

    International Nuclear Information System (INIS)

    Song, Chenxi; Li, Mingjia; Zhang, Fan; He, Ya-Ling; Tao, Wen-Quan

    2015-01-01

    Highlights: • Two kinds of energy efficiency (EE) indices are analyzed and compared. • The influence degrees of different uncontrollable factors on EE are compared. • The influence of load factor on special EE is 82.6% larger than capacity factor. • The influence of cooling method on special EE is 90.32% larger than steam pressure. • The generalized EE indicator is more recommended by the authors. - Abstract: In this article, the non-parametric data envelopment analysis method (DEA) is employed to evaluate energy efficiency (EE) of 34 coal-fired power units in China. Input-oriented CCR (Charnes, Cooper and Rhodes) model is used for EE analysis. Two efficiency indices, generalized EE and special EE are defined and analyzed. The generalized EE is calculated based on four input parameters: coal consumption, oil consumption, water consumption and auxiliary power consumption by power units. The special EE is only based on two input parameters: coal consumption and auxiliary power consumption. Relations between these two EE indices and non-comparable factors including quality of coal, load factor, capacity factor, parameters of main steam and cooling method are studied. Comparison between EE evaluation results of the two indices is conducted. Results show that these two kinds of EE are more sensitive to the load factor than the capacity factor. The influence of the cooling method on EE is larger than that of main steam parameter. The influence of non-comparable factors on the special EE is stronger than that on the generalized EE

  5. Water Flow Forecasting and River Simulation for Flood Risk Analysis

    OpenAIRE

    Merkurjeva, G

    2013-01-01

    The paper presents the state-of-the-art in flood forecasting and simulation applied to a river flood analysis and risk prediction. Different water flow forecasting and river simulation models are analysed. An advanced river flood forecasting and modelling approach developed within the ongoing project INFROM is described. It provides an integrated procedure for river flow forecasting and simulation advanced by integration of different models for improving predictions of th...

  6. Key parameters analysis of hybrid HEMP simulator

    International Nuclear Information System (INIS)

    Mao Congguang; Zhou Hui

    2009-01-01

    According to the new standards on the high-altitude electromagnetic pulse (HEMP) developed by International Electrotechnical Commission (IEC), the target parameter requirements of the key structure of the hybrid HEMP simulator are decomposed. Firstly, the influences of the different excitation sources and biconical structures to the key parameters of the radiated electric field wave shape are investigated and analyzed. Then based on the influence curves the target parameter requirements of the pulse generator are proposed. Finally the appropriate parameters of the biconical structure and the excitation sources are chosen, and the computational result of the electric field in free space is presented. The results are of great value for the design of the hybrid HEMP simulator. (authors)

  7. Status of the MIND simulation and analysis

    Science.gov (United States)

    Cervera Villanueva, A.; Laing, A.; Lindroos, L.; Martín-Albo, J.; Soler, F. J. P.

    2010-03-01

    A realistic simulation of the Neutrino Factory detectors is required in order to fully understand the sensitivity of such a facility to the remaining parameters and degeneracies of the neutrino mixing matrix. Here described is the status of a modular software framework being developed to accommodate such a study. The results of initial studies of the reconstruction software and expected efficiency curves in the context of the golden channel are given.

  8. A reliability simulation language for reliability analysis

    International Nuclear Information System (INIS)

    Deans, N.D.; Miller, A.J.; Mann, D.P.

    1986-01-01

    The results of work being undertaken to develop a Reliability Description Language (RDL) which will enable reliability analysts to describe complex reliability problems in a simple, clear and unambiguous way are described. Component and system features can be stated in a formal manner and subsequently used, along with control statements to form a structured program. The program can be compiled and executed on a general-purpose computer or special-purpose simulator. (DG)

  9. Generator dynamics in aeroelastic analysis and simulations

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, T.J.; Hansen, M.H.; Iov, F.

    2003-05-01

    This report contains a description of a dynamic model for a doubly-fed induction generator implemented in the aeroelastic code HAWC. The model has physical input parameters (resistance, reactance etc.) and input variables (stator and rotor voltage and rotor speed). The model can be used to simulate the generator torque as well as the rotor and stator currents, active and reactive power. A perturbation method has been used to reduce the original generator model equations to a set of equations which can be solved with the same time steps as a typical aeroelastic code. The method is used to separate the fast transients of the model from the slow variations and deduce a reduced order expression for the slow part. Dynamic effects of the first order terms in the model as well as the influence on drive train eigenfrequencies and damping has been investigated. Load response during time simulation of wind turbine response have been compared to simulations with a linear static generator model originally implemented i HAWC. A 2 MW turbine has been modelled in the aeroelastic code HAWC. When using the new dynamic generator model there is an interesting coupling between the generator dynamics and a global turbine vibration mode at 4.5 Hz, which only occurs when a dynamic formulation of the generator equations is applied. This frequency can especially be seen in the electrical power of the generator and the rotational speed of the generator, but also as torque variations in the drive train. (au)

  10. Merging Galaxy Clusters: Analysis of Simulated Analogs

    Science.gov (United States)

    Nguyen, Jayke; Wittman, David; Cornell, Hunter

    2018-01-01

    The nature of dark matter can be better constrained by observing merging galaxy clusters. However, uncertainty in the viewing angle leads to uncertainty in dynamical quantities such as 3-d velocities, 3-d separations, and time since pericenter. The classic timing argument links these quantities via equations of motion, but neglects effects of nonzero impact parameter (i.e. it assumes velocities are parallel to the separation vector), dynamical friction, substructure, and larger-scale environment. We present a new approach using n-body cosmological simulations that naturally incorporate these effects. By uniformly sampling viewing angles about simulated cluster analogs, we see projected merger parameters in the many possible configurations of a given cluster. We select comparable simulated analogs and evaluate the likelihood of particular merger parameters as a function of viewing angle. We present viewing angle constraints for a sample of observed mergers including the Bullet cluster and El Gordo, and show that the separation vectors are closer to the plane of the sky than previously reported.

  11. SCAR-B fires in the tropics: Properties and remote sensing from EOS-MODIS

    Science.gov (United States)

    Kaufman, Yoram J.; Kleidman, Richard G.; King, Michael D.

    1998-12-01

    Two moderate resolution imaging spectroradiometer (MODIS) instruments are planned for launch in 1999 and 2000 on the NASA Earth Observing System (EOS) AM-1 and EOS PM-1 satellites. The MODIS instrument will sense fires with designated 3.9 and 11 μm channels that saturate at high temperatures (450 and 400 K, respectively). MODIS data will be used to detect fires, to estimate the rate of emission of radiative energy from the fire, and to estimate the fraction of biomass burned in the smoldering phase. The rate of emission of radiative energy is a measure of the rate of combustion of biomass in the fires. In the Smoke, Clouds, and Radiation-Brazil (SCAR-B) experiment the NASA ER-2 aircraft flew the MODIS airborne simulator (MAS) to measure the fire thermal and mid-IR signature with a 50 m spatial resolution. These data are used to observe the thermal properties and sizes of fires in the cerrado grassland and Amazon forests of Brazil and to simulate the performance of the MODIS 1 km resolution fire observations. Although some fires saturated the MAS 3.9 μm channel, all the fires were well within the MODIS instrument saturation levels. Analysis of MAS data over different ecosystems, shows that the fire size varied from single MAS pixels (50×50 m) to over 1 km2. The 1×1 km resolution MODIS instrument can observe only 30-40% of these fires, but the observed fires are responsible for 80 to nearly 100% of the emitted radiative energy and therefore for 80 to 100% of the rate of biomass burning in the region. The rate of emission of radiative energy from the fires correlated very well with the formation of fire burn scars (correlation coefficient = 0.97). This new remotely sensed quantity should be useful in regional estimates of biomass consumption.

  12. Fire fighting capability assessment program Darlington NGS

    International Nuclear Information System (INIS)

    1995-05-01

    This is a report on the completion of work relating to the assessment of the capability of Darlington NGS to cope with a large fire incident. This included an evaluation of an exercise scenario that would simulate a large fire incident and of their fire plans and procedures which became the subject of interim reports as part of the process of preparing for the fire fighting and rescue exercise. Finally the execution of fire plans by Darlington Nuclear Generating Station (NGS), as demonstrated by their application of human and material resources during a simulated large fire, was observed. 1 tab., 1 fig

  13. Coupled Monte Carlo simulation and Copula theory for uncertainty analysis of multiphase flow simulation models.

    Science.gov (United States)

    Jiang, Xue; Na, Jin; Lu, Wenxi; Zhang, Yu

    2017-11-01

    Simulation-optimization techniques are effective in identifying an optimal remediation strategy. Simulation models with uncertainty, primarily in the form of parameter uncertainty with different degrees of correlation, influence the reliability of the optimal remediation strategy. In this study, a coupled Monte Carlo simulation and Copula theory is proposed for uncertainty analysis of a simulation model when parameters are correlated. Using the self-adaptive weight particle swarm optimization Kriging method, a surrogate model was constructed to replace the simulation model and reduce the computational burden and time consumption resulting from repeated and multiple Monte Carlo simulations. The Akaike information criterion (AIC) and the Bayesian information criterion (BIC) were employed to identify whether the t Copula function or the Gaussian Copula is the optimal Copula function to match the relevant structure of the parameters. The results show that both the AIC and BIC values of the t Copula function are less than those of the Gaussian Copula function. This indicates that the t Copula function is the optimal function for matching the relevant structure of the parameters. The outputs of the simulation model when parameter correlation was considered and when it was ignored were compared. The results show that the amplitude of the fluctuation interval when parameter correlation was considered is less than the corresponding amplitude when parameter estimation was ignored. Moreover, it was demonstrated that considering the correlation among parameters is essential for uncertainty analysis of a simulation model, and the results of uncertainty analysis should be incorporated into the remediation strategy optimization process.

  14. Augmenting health care failure modes and effects analysis with simulation

    DEFF Research Database (Denmark)

    Staub-Nielsen, Ditte Emilie; Dieckmann, Peter; Mohr, Marlene

    2014-01-01

    This study explores whether simulation plays a role in health care failure mode and effects analysis (HFMEA); it does this by evaluating whether additional data are found when a traditional HFMEA is augmented with simulation. Two multidisciplinary teams identified vulnerabilities in a process by ...

  15. Fire investigation

    Science.gov (United States)

    Gomberg, A.

    There was considerable progress made on several fronts of fire investigation in the United States in recent years. Progress was made in increasing the quantity of fire investigation and reporting, through efforts to develop the National Fire Incident Reporting System. Improving overall quality of fire investigation is the objective of efforts such as the Fire Investigation Handbook, which was developed and published by the National Bureau of Standards, and the upgrading and expanding of the ""dictionary'' of fire investigation and reporting, the NFPA 901, Uniform Coding for Fire Protection, system. The science of fire investigation as furthered also by new approaches to post fire interviews being developed at the University of Washington, and by in-depth research into factors involved in several large loss fires, including the MGM Grand Hotel in Las Vegas. Finally, the use of special study fire investigations - in-depth investigations concentrating on specific fire problems - is producing new glimpses into the nature of the national fire problem. A brief description of the status of efforts in each of these areas is discussed.

  16. Analysis, Simulation, and Verification of Knowledge-Based, Rule-Based, and Expert Systems

    Science.gov (United States)

    Hinchey, Mike; Rash, James; Erickson, John; Gracanin, Denis; Rouff, Chris

    2010-01-01

    Mathematically sound techniques are used to view a knowledge-based system (KBS) as a set of processes executing in parallel and being enabled in response to specific rules being fired. The set of processes can be manipulated, examined, analyzed, and used in a simulation. The tool that embodies this technology may warn developers of errors in their rules, but may also highlight rules (or sets of rules) in the system that are underspecified (or overspecified) and need to be corrected for the KBS to operate as intended. The rules embodied in a KBS specify the allowed situations, events, and/or results of the system they describe. In that sense, they provide a very abstract specification of a system. The system is implemented through the combination of the system specification together with an appropriate inference engine, independent of the algorithm used in that inference engine. Viewing the rule base as a major component of the specification, and choosing an appropriate specification notation to represent it, reveals how additional power can be derived from an approach to the knowledge-base system that involves analysis, simulation, and verification. This innovative approach requires no special knowledge of the rules, and allows a general approach where standardized analysis, verification, simulation, and model checking techniques can be applied to the KBS.

  17. Leachate analysis of green and fired-clay bricks incorporated with biosolids.

    Science.gov (United States)

    Ukwatta, Aruna; Mohajerani, Abbas

    2017-08-01

    The substantial increase in biosolids production throughout the world requires sustainable routes for reuse. This study describes the leaching behaviour of potentially hazardous metals from the green and fired bricks incorporating four different biosolids samples from the Eastern treatment plant (ETP) and Western treatment plant (WTP) in Melbourne. The biosolids samples were characterized by XRD, XRF, TGA, particle size distribution, and organic content. The leaching of As, Ag, Ba, Be, Cd, Cr, Cu, Mo, Ni, Pb, Sb, Se, and Zn was evaluated for both the green and the fired bricks according to the Toxicity characteristic leaching procedure (TCLP) and the Australian bottle leaching procedure (ABLP). The leaching of heavy metals from both the green and the fired bricks was compared to investigate the effect of firing on the leaching capability of bricks. The results showed that the leaching of heavy metals from fired bricks was significantly lower than that for the green bricks. The ABLP concentrations of heavy metals were higher than those found using the TCLP method, mainly due to the higher specific surface area of the particles used in the ABLP method. Moreover, bricks were evaluated by the technological properties, such as compressive strength, density and water absorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Analysis of 210Po in the gaseous effluent from the coal-fired boiler

    International Nuclear Information System (INIS)

    Li Shutang

    1992-01-01

    The concentrations of 210 Po in crude coal, slag and flue dust from coal-fired boilers, coal-fired power plants and coal-fired boiler for supplying boiling water in nuclear industrial system of China are analysed. The distribution of 210 Po is investigated. The results are as follows: the average concentrations of 210 Po in the crude coal and slag are 27 Bq/kg and 17.6 Bq/kg, respectively. 210 Po is moved toward the stack and released to the atmosphere along with the hot flue gases from the coal-fired boilers. The concentration (C) of 210 Po in flue gases is increases gradually. The distribution of 210 Po is as follows: C before the dust remover 210 Po in crude coal is enriched very much in the gaseous effluent from burnt coal. 210 Po is the most high toxic nuclide and the 210 Po release from the stack will be harmful to the residents. Therefore, in order to remove the black smoke and 210 Po in the stack, the efficiency of a dust remover for coal-fired boiler must be more than 90%

  19. Energy, exergy, environmental and economic analysis of industrial fired heaters based on heat recovery and preheating techniques

    International Nuclear Information System (INIS)

    Shekarchian, M.; Zarifi, F.; Moghavvemi, M.; Motasemi, F.; Mahlia, T.M.I.

    2013-01-01

    Highlights: • 4-E analysis of a typical industrial grade fired heater unit is studied. • This analysis is accomplished for the first time in this study. • Heat recovery and air preheating lead to substantial reduction in the fuel consumption. • The company’s current costs are tremendously reduced by these methods. • The methods lead to mitigation in GHG emission and to reduction in the associated taxes. - Abstract: Fired heaters are ubiquitous in both the petroleum and petrochemical industries, due to it being vital in their day to day operations. They form major components in petroleum refineries, petrochemical facilities, and processing units. This study was commissioned in order to analyze the economic benefits of incorporating both heat recovery and air preheating methods into the existing fired heater units. Four fired heater units were analyzed from the energy and environmental point of views. Moreover, the second law efficiency and the rate of irreversibility were also analyzed via the exergy analysis. Both analyses was indicative of the fact that the heat recovery process enhances both the first and second law efficiencies while simultaneously assisting in the production of high and low pressure water steam. The implementation and usage of the process improves the thermal and exergy efficiencies from 63.4% to 71.7% and 49.4%, to 54.8%, respectively. Additionally, the heat recovery and air preheating methods leads to a substantial reduction in fuel consumption, in the realm of up to 7.4%, while also simultaneously decreasing heat loss and the irreversibility of the unit. Nevertheless, the results of the economic analysis posits that although utilizing an air preheater unit enhances the thermal performance of the system, due to the air preheater’s capital and maintenance costs, incorporating an air preheater unit to an existing fired heater is not economically justifiable. Furthermore, the results of the sensitivity analysis and payback period

  20. Freud: a software suite for high-throughput simulation analysis

    Science.gov (United States)

    Harper, Eric; Spellings, Matthew; Anderson, Joshua; Glotzer, Sharon

    Computer simulation is an indispensable tool for the study of a wide variety of systems. As simulations scale to fill petascale and exascale supercomputing clusters, so too does the size of the data produced, as well as the difficulty in analyzing these data. We present Freud, an analysis software suite for efficient analysis of simulation data. Freud makes no assumptions about the system being analyzed, allowing for general analysis methods to be applied to nearly any type of simulation. Freud includes standard analysis methods such as the radial distribution function, as well as new methods including the potential of mean force and torque and local crystal environment analysis. Freud combines a Python interface with fast, parallel C + + analysis routines to run efficiently on laptops, workstations, and supercomputing clusters. Data analysis on clusters reduces data transfer requirements, a prohibitive cost for petascale computing. Used in conjunction with simulation software, Freud allows for smart simulations that adapt to the current state of the system, enabling the study of phenomena such as nucleation and growth, intelligent investigation of phases and phase transitions, and determination of effective pair potentials.