Simo Hostikka | Aalto University (original) (raw)
Papers by Simo Hostikka
Proceeding of Proceedings of the 9th International Symposium on Radiative Transfer, RAD-19
The spectral characteristics of radiation coming from a pool fire flame are numerically obtained.... more The spectral characteristics of radiation coming from a pool fire flame are numerically obtained. The case study is a 2m n-heptane pool fire located in the bottom of a 4m×4m×5m rectangular domain. Transient heat and mass transfer of the system was solved using CFD code Fire Dynamic Simulator (FDS) with LES of turbulence and a two-step combustion reaction. The time averaged solution data of gas compositions, soot concentration and temperature along a line in the system were collected. Using the time averaged CFD data, two different onedimensional models assuming parallel plate conditions and a line of sight solution were built to study the spectral radiative intensity observed outside the flame. The high-resolution LBL spectral absorption profiles of combustion gases together with a spectral model for soot absorption coefficient were used in spectral solution of thermal radiation along the line for both assumptions of parallel plates (using DO method) and line of the sight conditions. The spectral radiation profile reaching an imaginary sensor is qualitatively compared with the recently published experimental data of Kerosene large pool fires. The modelling results revealed the strong absorption effect of cold atmospheric gases while the emission peak of hot CO2 at ~2200cm-1 in fire is still quite distinguishable from the spectral profile of hot blackbody even at 23 meters away from the center of the flame. This emission peak can be therefore used for detection of the fire. Using the scaled CFD data for smaller pools showed that the difference between the spectral profiles of the fire and those of hot blackbodies is larger for smaller pools. It means that the detection of smaller fires using the spectral radiation characteristics is easier than that of larger fires where strong effect of soot emission caused more blackbody-like behavior.
International Journal of Heat and Mass Transfer, 2018
Fire Safety Journal, 2017
Studies on accidental gas and dust explosions Safe evacuation for all-Fact or Fantasy? Past exper... more Studies on accidental gas and dust explosions Safe evacuation for all-Fact or Fantasy? Past experiences, current understanding and future challenges A review of physics and correlations of pool fire behaviour in wind and future challenges Structural response of cross-laminated timber compression elements exposed to fire The effect of flow and geometry on concurrent flame spread Fire toxicity-The elephant in the room? Stochastic modeling of firebrand shower scenarios Motivation, drivers and barriers for a knowledge-based test environment in structural fire safety engineering science Material Behavior in Fires Flame spread over horizontal and vertical wires: The role of dripping and core Measurement of instantaneous flame spread rate over solid fuels using image analysis Controlled atmosphere pyrolysis apparatus II (CAPA II): A new tool for analysis of pyrolysis of charring and intumescent polymers Gravimetric measurement of solid and liquid fuel burning rate near and at the low oxygen extinction limit Spontaneous combustion coal parameters for the Crossing-Point Temperature (CPT) method in a Temperature-Programmed System (TPS) Effectiveness of vertical barriers in preventing lateral flame spread over exposed EPS insulation wall Char cracking of medium density fibreboard due to thermal shock effect induced pyrolysis shrinkage Heat release characteristics of ethanol-water mixtures: Small-scale experiments Effect of oxygen concentration on the combustion of horizontally-oriented slabs of PMMA Pyrolysis kinetics and multi-objective inverse modelling of cellulose at the microscale Simultaneous improvements in flammability and mechanical toughening of epoxy resins through nano-silica addition Fully coupled CFD simulation of the pyrolysis of non-charring polymers: A predictive approach Pyrolysis and spontaneous ignition of wood under transient irradiation: Experiments and a-priori predictions Flammability of CS 2 and other reduced sulfur species Enhanced ignition of biomass in presence of NO x Two-dimensional model of smouldering combustion using multi-layer cellular automaton: The role of ignition location and direction of airflow Critical heat flux and mass loss rate for extinction of flaming combustion of timber Flame spread limits (LOC) of fire resistant fabrics Fire Dynamics Predicting the heat release rates of liquid pool fires in mechanically ventilated compartments Study of FDS simulations of buoyant fire-induced smoke movement in a high-rise building stairwell Using suppression and detection devices to steer CFD fire forecast simulations Risk analysis of unburnt gas ignition in an exhaust system connected to a confined and mechanically ventilated enclosure fire Effect of cross section on critical velocity in longitudinally ventilated tunnel fires Modeling for predicting the temperature distribution of smoke during a fire in an underground road tunnel with vertical shafts An experimental study on backdraught: The dependence on temperature Description of small and large-scale cross laminated timber fire tests Interaction between water spray and smoke in a fire event in a confined and mechanically ventilated enclosure Spread and burning behavior of continuous spill fires Two-layer zone model including entrainment into the horizontally spreading smoke under the ceiling for application to fires in large area rooms Grouping methods for MPS soot transport model and its application in large-scale enclosure fires Experimental investigation on transverse ceiling flame length and temperature distribution of sidewall confined tunnel fire Fire-induced pressure and smoke spreading in mechanically ventilated buildings with airtight envelopes Experimental and numerical evaluation of the influence of the soot yield on the visibility in smoke in CFD analysis Spilled liquid fires in tunnels Auto-extinction of engineered timber: Application to compartment fires with exposed timber surfaces Wind effects on flame projection probability from a compartment with opposing openings Energy distribution analysis in full-scale open floor plan enclosure fires Fire development in a 1/3 train carriage mock-up A small-world network model for the simulation of fire spread onboard naval vessels Thermal characteristics of externally venting flames and their effect on the exposed façade surface Temperature and velocity distributions from numerical simulations of ceiling jets under unconfined, inclined ceilings Predicting the structural response of a compartment fire using full-field heat transfer measurements Effects of exposed cross laminated timber on compartment fire dynamics Spectral radiation intensities of a turbulent buoyant ethylene flame: CFD-aided tomographic inversion Structures in Fire Fire response of exterior reinforced concrete beam-column subassemblages An experimental study on the temperature and structural behavior of a concrete wall exposed to fire after a high-velocity impact by a hard projectile Uncertainty propagation in FE modelling of a fire resistance test using fractional factorial design based model reduction and deterministic sampling Behavior of steel-sheathed shear walls subjected to seismic and fire loads Optimising design decision-making for steel structures in fire using a hybrid analysis technique Structural response of a steel-frame building to horizontal and vertical travelling fires in multiple floors Impact of melting and burnout of polypropylene fibre on air permeability and mechanical properties of high-strength concrete Modeling post-fire behavior of aluminum structural components using a maximum temperature approach A critical review of "travelling fire" scenarios for performance-based structural engineering Determination of fire resistance ratings for glulam connectors within US high rise timber buildings Fire Suppression Influence of the particle injection rate, droplet size distribution and volume flux angular distribution on the results and computational time of water spray CFD simulations Physical scaling of water mist fire extinguishment in industrial machinery enclosures An experimental study of complex fuel burning behavior with water application Electrically controlled dynamic sprinkler activation: Computational assessment of potential efficiency Effects of storage height on critical delivered flux of representative fuels An experimental study of fire growth and suppression of roll paper at small scales Development and evaluation of two new droplet evaporation schemes for fire dynamics simulations Measuring fuel transport through fluorocarbon and fluorine-free firefighting foams Measuring modified glass bulb sprinkler thermal response in plunge and compartment fire experiments Experimental study of the effect of water spray on the spread of smoldering in Indonesian peat fires Modeling of fire suppression by fuel cooling A computational study of extinguishment and enhancement of propane cup-burner flames by halon and alternative agents Large-scale fire suppression modeling of corrugated cardboard boxes on wood pallets in rack-storage configurations Water mist suppression of a turbulent line fire Measurements of spray-plume interactions for model validation Spatially-resolved spray measurements and their implications Extinguishing characteristics of a diffusion flame with water vapor produced from a water droplet impacting onto a heated plate Wildland Fires Investigating coherent streaks in wildfires via heated plates in crosswind An experimental study on the intermittent extension of flames in wind-driven fires A computational study of the interactions of three adjacent burning shrubs subjected to wind Evaluation of a data-driven wildland fire spread forecast model with spatially-distributed parameter estimation in simulations of the FireFlux I field-scale experiment Mapping areas at elevated risk of large-scale structure loss using Monte Carlo simulation and wildland fire modeling Verification of a Lagrangian particle model for short-range firebrand transport Experiments to provide the scientific-basis for laboratory standard test methods for firebrand exposure Determination of smoldering time and thermal characteristics of firebrands under laboratory conditions Characterization of aerosols emissions from the combustion of dead shrub twigs and leaves using a cone calorimeter Investigation of thermal degradation of pine needles using multi-step reaction mechanisms A study to investigate pyrolysis of wood particles of various shapes and sizes Self-ignition of natural fuels: Can wildfires of carbon-rich soil start by self-heating? An integrated approach for tactical monitoring and data-driven spread forecasting of wildfires Utilization of remote sensing techniques for the quantification of fire behavior in two pine stands Experimental investigation of the impact of oxygen flux on the burning dynamics of forest fuel beds Investigation of firebrand generation from an experimental fire: Development of a reliable data collection methodology Real-time wildland fire spread modeling using tabulated flame properties Evacuation and Human Behavior Transparency vs magic numbers: The development of stair design requirements in the Italian Fire Safety Code A forensic analysis of a fatal fire in an indoor shooting range using coupled fire and evacuation modelling tools Evacuation speed in full-scale darkened tunnel filled with smoke Evaluating the effectiveness of an improved active dynamic signage system using full scale evacuation trials Pedestrian merging behavior analysis: An experimental study Noticeability of illuminated route signs for tsunami evacuation Human behaviour during evacuation of primary schools: Investigations on pre-evacuation times, movement on stairways and movement on the horizontal plane Real-time evacuation route selection methodology for complex buildings Perspectives of occupants with mobility impairments on evacuation methods for use during fire emergencies
of Combustion Science and Engineering (CSE) implemented a smoke detector activation model within ... more of Combustion Science and Engineering (CSE) implemented a smoke detector activation model within FDS and also validated various parts of the model. Doug Carpenter and Erin Mack Ashley of CSE conducted the literature review that is now part of the FDS Technical Reference Guide. Jason Floyd and Javier Trelles, former NIST post-docs now working at Hughes Associates, continue to make vital contributions to the model because of their familiarity with the source code. Chris Wood of ArupFire, Dave Sheppard of the US Bureau of Alcohol, Tobacco and Firearms (ATF), and Doug Carpenter of Combustion Science and Engineering developed a training course on the use of FDS and Smokeview on behalf of the Society of Fire Protection Engineers (SFPE). Morgan Hurley of the SFPE supported this effort. Prof. David McGill of Seneca College, Ontario, Canada has also conducted a remotelearning course on the use of FDS. Prof. Ian Thomas of Victoria University has presented short courses on the use of FDS in Australia. His students have also performed some validation work on compartment fires. At the University of Maryland, Professors Fred Mowrer, Jim Quintiere, Jose Torero and Marino di Marzo have supervised students who have conducted validation work with FDS. In particular, Phil Friday and T. Ma have performed extensive validation work on the basic hydrodynamic solvers, and Paulo Ruffino has studied the activation of sprinklers that have been wetted by previously activated sprinklers. Profs. Arnaud Trouve and Andre Marshall are presently studying the application of FDS to under-ventilated fires. At Worcester Polytechnic Institute (WPI), Prof. Johnathan Barnett has supervised several students, in particular Jay Ierardi and Chris Lautenberger, who have experimented with more detailed combustion models for small-scale applications. At Northwestern University, Prof. Richard Lueptow has advised doctoral students Dave Sheppard and Jay Schwille whose research involved measurements of water sprays from sprinklers and mist nozzles. At the University of Illinois, Chicago, Prof. Ishwar Puri along with students Anurag Jhalani and Achintya Mukhopadhyay validated the model against slot burner measurements. The purpose of their study was to quantify the effects of flame stretch. At Virginia Tech, Prof. Uri Vandsburger hosted NIST Post-Doc Jason Floyd during his two-year tenure at NIST. Doctoral student Chris Wieczorek performed a series of compartment fire experiments used in part to validate FDS.
His research interests include subgrid-scale models and numerical methods for large-eddy simulati... more His research interests include subgrid-scale models and numerical methods for large-eddy simulation, adaptive mesh refinement, immersed boundary methods, and Lagrangian particle methods.
VTT Tiedotteita - Valtion Teknillinen Tutkimuskeskus
Survivability of ships in case of fire has been studied in the SURSHIP-FIRE research project as a... more Survivability of ships in case of fire has been studied in the SURSHIP-FIRE research project as a part of the SURSHIP cooperation, a coordinated European research program on Maritime safety. The work was performed in four subprojects related to materials used in shipbuilding, fire hazards on board, ship structures, and evacuation in ship conditions. Fire test data of products commonly used in shipbuilding were stored to a free-of-charge accessible database for the use of design engineers. Guidelines were defined for using fire test data in simulation and product development. Procedures for quantitative fire risk analyses of cabins and cabin areas were defined, applicable also to other cases with different features and details. A methodology for defining design fires for various ship spaces was formulated and applied to shops on board as a practical example. The sophisticated simulation and risk analysis tools utilized in the work were the FDS5 fire simulation program with its evacuation module FDS+Evac, the Probabilistic Fire Simulator, and the method of time-dependent event trees. The effects of engine room fires on car deck structures were analysed in detail since the situation was recognised critical for the structural integrity of the ship. Thermal and mechanical analyses of the structures with different dimensions and insulation extents were performed considering both the standard fire curve and the hydrocarbon curve. A survey of specific features of ship evacuation was carried out. Since the use of staircases and the movement of evacuees between decks is an essential part of ship evacuation, a new staircase submodel for the FDS+Evac program was created, verified and validated. The results of the SURSHIP-FIRE project can influence on IMO rules for alternative fire safety design of ships. The contributions of SURSHIP-FIRE are guidelines for using fire test data as input of simulations, a methodology for estimation of design fires, practices for quantitative risk analyses, a summary of critical fire situations for structures, and suggested improvements of the IMO guidelines for evacuation analyses.
Malli rakennettiin käyttäen neuroverkkojen itseorganisoituvia karttoja (SOM), jotka ovat yksi neu... more Malli rakennettiin käyttäen neuroverkkojen itseorganisoituvia karttoja (SOM), jotka ovat yksi neuroverkkojen tyyppi. Neuroverkot ovat epälineaarinen estimointimenetelmä, joiden perusajatus tulee luonnollisista neuroverkoista. Neuroverkkoa opetetaan esimerkkien avulla, ja se oppii muuttujien epälineaariset riip-5. Itseorganisoituvat kartat (SOM)
The reliability of the nuclear power plant safety systems relies strongly on the concept of redun... more The reliability of the nuclear power plant safety systems relies strongly on the concept of redundancy. In some plant designs, cables of two subsystems can exist in the same room. In this work, Monte Carlo fire simulations of this kind of cable tunnel are performed. The goal of these simulations is to estimate the time dependent probabilities of cable failures and other events in case of a cable fire starting from the power cables of one subsystem. The simulations compare consequences with and without an operating sprinkler system.
Electrical cables constitute the major part of the fire loads in nuclear power plants and may als... more Electrical cables constitute the major part of the fire loads in nuclear power plants and may also serve as ignition sources, contributing significantly to the overall risk. In this paper, the numerical methods for describing the thermal degradation of cable component materials are presented. Analytical techniques based on genetic algorithms for estimating the necessary model parameters from the small and bench scale experimental data have been used and the procedure for parameter estimation is reported. As a special topic, the modelling of the fire retardant cable materials is discussed.
Fire Safety Science, 2011
One of the most commonly used materials in electrical cables is flexible PVC. In this work, the e... more One of the most commonly used materials in electrical cables is flexible PVC. In this work, the effects of the modelling decisions and parameter estimation methods on the pyrolysis modelling of two PVC cables were studied. The kinetic and thermal parameters were estimated from TGA and cone calorimeter experiments. The role of the plasticizers was shown to be important for the early HRR. The effects of the reaction path and reaction order were only minor in the TGA results but significant effects were found in the cone calorimeter results, unless a specific set of thermal parameters was estimated. The results show that the thermal parameters estimated for one kinetic model should not be used for another, unless the kinetic models only differ in fuel yields or different pairs of kinetic coefficients with same reaction order.
Proceeding of Proceedings of the 9th International Symposium on Radiative Transfer, RAD-19
The spectral characteristics of radiation coming from a pool fire flame are numerically obtained.... more The spectral characteristics of radiation coming from a pool fire flame are numerically obtained. The case study is a 2m n-heptane pool fire located in the bottom of a 4m×4m×5m rectangular domain. Transient heat and mass transfer of the system was solved using CFD code Fire Dynamic Simulator (FDS) with LES of turbulence and a two-step combustion reaction. The time averaged solution data of gas compositions, soot concentration and temperature along a line in the system were collected. Using the time averaged CFD data, two different onedimensional models assuming parallel plate conditions and a line of sight solution were built to study the spectral radiative intensity observed outside the flame. The high-resolution LBL spectral absorption profiles of combustion gases together with a spectral model for soot absorption coefficient were used in spectral solution of thermal radiation along the line for both assumptions of parallel plates (using DO method) and line of the sight conditions. The spectral radiation profile reaching an imaginary sensor is qualitatively compared with the recently published experimental data of Kerosene large pool fires. The modelling results revealed the strong absorption effect of cold atmospheric gases while the emission peak of hot CO2 at ~2200cm-1 in fire is still quite distinguishable from the spectral profile of hot blackbody even at 23 meters away from the center of the flame. This emission peak can be therefore used for detection of the fire. Using the scaled CFD data for smaller pools showed that the difference between the spectral profiles of the fire and those of hot blackbodies is larger for smaller pools. It means that the detection of smaller fires using the spectral radiation characteristics is easier than that of larger fires where strong effect of soot emission caused more blackbody-like behavior.
International Journal of Heat and Mass Transfer, 2018
Fire Safety Journal, 2017
Studies on accidental gas and dust explosions Safe evacuation for all-Fact or Fantasy? Past exper... more Studies on accidental gas and dust explosions Safe evacuation for all-Fact or Fantasy? Past experiences, current understanding and future challenges A review of physics and correlations of pool fire behaviour in wind and future challenges Structural response of cross-laminated timber compression elements exposed to fire The effect of flow and geometry on concurrent flame spread Fire toxicity-The elephant in the room? Stochastic modeling of firebrand shower scenarios Motivation, drivers and barriers for a knowledge-based test environment in structural fire safety engineering science Material Behavior in Fires Flame spread over horizontal and vertical wires: The role of dripping and core Measurement of instantaneous flame spread rate over solid fuels using image analysis Controlled atmosphere pyrolysis apparatus II (CAPA II): A new tool for analysis of pyrolysis of charring and intumescent polymers Gravimetric measurement of solid and liquid fuel burning rate near and at the low oxygen extinction limit Spontaneous combustion coal parameters for the Crossing-Point Temperature (CPT) method in a Temperature-Programmed System (TPS) Effectiveness of vertical barriers in preventing lateral flame spread over exposed EPS insulation wall Char cracking of medium density fibreboard due to thermal shock effect induced pyrolysis shrinkage Heat release characteristics of ethanol-water mixtures: Small-scale experiments Effect of oxygen concentration on the combustion of horizontally-oriented slabs of PMMA Pyrolysis kinetics and multi-objective inverse modelling of cellulose at the microscale Simultaneous improvements in flammability and mechanical toughening of epoxy resins through nano-silica addition Fully coupled CFD simulation of the pyrolysis of non-charring polymers: A predictive approach Pyrolysis and spontaneous ignition of wood under transient irradiation: Experiments and a-priori predictions Flammability of CS 2 and other reduced sulfur species Enhanced ignition of biomass in presence of NO x Two-dimensional model of smouldering combustion using multi-layer cellular automaton: The role of ignition location and direction of airflow Critical heat flux and mass loss rate for extinction of flaming combustion of timber Flame spread limits (LOC) of fire resistant fabrics Fire Dynamics Predicting the heat release rates of liquid pool fires in mechanically ventilated compartments Study of FDS simulations of buoyant fire-induced smoke movement in a high-rise building stairwell Using suppression and detection devices to steer CFD fire forecast simulations Risk analysis of unburnt gas ignition in an exhaust system connected to a confined and mechanically ventilated enclosure fire Effect of cross section on critical velocity in longitudinally ventilated tunnel fires Modeling for predicting the temperature distribution of smoke during a fire in an underground road tunnel with vertical shafts An experimental study on backdraught: The dependence on temperature Description of small and large-scale cross laminated timber fire tests Interaction between water spray and smoke in a fire event in a confined and mechanically ventilated enclosure Spread and burning behavior of continuous spill fires Two-layer zone model including entrainment into the horizontally spreading smoke under the ceiling for application to fires in large area rooms Grouping methods for MPS soot transport model and its application in large-scale enclosure fires Experimental investigation on transverse ceiling flame length and temperature distribution of sidewall confined tunnel fire Fire-induced pressure and smoke spreading in mechanically ventilated buildings with airtight envelopes Experimental and numerical evaluation of the influence of the soot yield on the visibility in smoke in CFD analysis Spilled liquid fires in tunnels Auto-extinction of engineered timber: Application to compartment fires with exposed timber surfaces Wind effects on flame projection probability from a compartment with opposing openings Energy distribution analysis in full-scale open floor plan enclosure fires Fire development in a 1/3 train carriage mock-up A small-world network model for the simulation of fire spread onboard naval vessels Thermal characteristics of externally venting flames and their effect on the exposed façade surface Temperature and velocity distributions from numerical simulations of ceiling jets under unconfined, inclined ceilings Predicting the structural response of a compartment fire using full-field heat transfer measurements Effects of exposed cross laminated timber on compartment fire dynamics Spectral radiation intensities of a turbulent buoyant ethylene flame: CFD-aided tomographic inversion Structures in Fire Fire response of exterior reinforced concrete beam-column subassemblages An experimental study on the temperature and structural behavior of a concrete wall exposed to fire after a high-velocity impact by a hard projectile Uncertainty propagation in FE modelling of a fire resistance test using fractional factorial design based model reduction and deterministic sampling Behavior of steel-sheathed shear walls subjected to seismic and fire loads Optimising design decision-making for steel structures in fire using a hybrid analysis technique Structural response of a steel-frame building to horizontal and vertical travelling fires in multiple floors Impact of melting and burnout of polypropylene fibre on air permeability and mechanical properties of high-strength concrete Modeling post-fire behavior of aluminum structural components using a maximum temperature approach A critical review of "travelling fire" scenarios for performance-based structural engineering Determination of fire resistance ratings for glulam connectors within US high rise timber buildings Fire Suppression Influence of the particle injection rate, droplet size distribution and volume flux angular distribution on the results and computational time of water spray CFD simulations Physical scaling of water mist fire extinguishment in industrial machinery enclosures An experimental study of complex fuel burning behavior with water application Electrically controlled dynamic sprinkler activation: Computational assessment of potential efficiency Effects of storage height on critical delivered flux of representative fuels An experimental study of fire growth and suppression of roll paper at small scales Development and evaluation of two new droplet evaporation schemes for fire dynamics simulations Measuring fuel transport through fluorocarbon and fluorine-free firefighting foams Measuring modified glass bulb sprinkler thermal response in plunge and compartment fire experiments Experimental study of the effect of water spray on the spread of smoldering in Indonesian peat fires Modeling of fire suppression by fuel cooling A computational study of extinguishment and enhancement of propane cup-burner flames by halon and alternative agents Large-scale fire suppression modeling of corrugated cardboard boxes on wood pallets in rack-storage configurations Water mist suppression of a turbulent line fire Measurements of spray-plume interactions for model validation Spatially-resolved spray measurements and their implications Extinguishing characteristics of a diffusion flame with water vapor produced from a water droplet impacting onto a heated plate Wildland Fires Investigating coherent streaks in wildfires via heated plates in crosswind An experimental study on the intermittent extension of flames in wind-driven fires A computational study of the interactions of three adjacent burning shrubs subjected to wind Evaluation of a data-driven wildland fire spread forecast model with spatially-distributed parameter estimation in simulations of the FireFlux I field-scale experiment Mapping areas at elevated risk of large-scale structure loss using Monte Carlo simulation and wildland fire modeling Verification of a Lagrangian particle model for short-range firebrand transport Experiments to provide the scientific-basis for laboratory standard test methods for firebrand exposure Determination of smoldering time and thermal characteristics of firebrands under laboratory conditions Characterization of aerosols emissions from the combustion of dead shrub twigs and leaves using a cone calorimeter Investigation of thermal degradation of pine needles using multi-step reaction mechanisms A study to investigate pyrolysis of wood particles of various shapes and sizes Self-ignition of natural fuels: Can wildfires of carbon-rich soil start by self-heating? An integrated approach for tactical monitoring and data-driven spread forecasting of wildfires Utilization of remote sensing techniques for the quantification of fire behavior in two pine stands Experimental investigation of the impact of oxygen flux on the burning dynamics of forest fuel beds Investigation of firebrand generation from an experimental fire: Development of a reliable data collection methodology Real-time wildland fire spread modeling using tabulated flame properties Evacuation and Human Behavior Transparency vs magic numbers: The development of stair design requirements in the Italian Fire Safety Code A forensic analysis of a fatal fire in an indoor shooting range using coupled fire and evacuation modelling tools Evacuation speed in full-scale darkened tunnel filled with smoke Evaluating the effectiveness of an improved active dynamic signage system using full scale evacuation trials Pedestrian merging behavior analysis: An experimental study Noticeability of illuminated route signs for tsunami evacuation Human behaviour during evacuation of primary schools: Investigations on pre-evacuation times, movement on stairways and movement on the horizontal plane Real-time evacuation route selection methodology for complex buildings Perspectives of occupants with mobility impairments on evacuation methods for use during fire emergencies
of Combustion Science and Engineering (CSE) implemented a smoke detector activation model within ... more of Combustion Science and Engineering (CSE) implemented a smoke detector activation model within FDS and also validated various parts of the model. Doug Carpenter and Erin Mack Ashley of CSE conducted the literature review that is now part of the FDS Technical Reference Guide. Jason Floyd and Javier Trelles, former NIST post-docs now working at Hughes Associates, continue to make vital contributions to the model because of their familiarity with the source code. Chris Wood of ArupFire, Dave Sheppard of the US Bureau of Alcohol, Tobacco and Firearms (ATF), and Doug Carpenter of Combustion Science and Engineering developed a training course on the use of FDS and Smokeview on behalf of the Society of Fire Protection Engineers (SFPE). Morgan Hurley of the SFPE supported this effort. Prof. David McGill of Seneca College, Ontario, Canada has also conducted a remotelearning course on the use of FDS. Prof. Ian Thomas of Victoria University has presented short courses on the use of FDS in Australia. His students have also performed some validation work on compartment fires. At the University of Maryland, Professors Fred Mowrer, Jim Quintiere, Jose Torero and Marino di Marzo have supervised students who have conducted validation work with FDS. In particular, Phil Friday and T. Ma have performed extensive validation work on the basic hydrodynamic solvers, and Paulo Ruffino has studied the activation of sprinklers that have been wetted by previously activated sprinklers. Profs. Arnaud Trouve and Andre Marshall are presently studying the application of FDS to under-ventilated fires. At Worcester Polytechnic Institute (WPI), Prof. Johnathan Barnett has supervised several students, in particular Jay Ierardi and Chris Lautenberger, who have experimented with more detailed combustion models for small-scale applications. At Northwestern University, Prof. Richard Lueptow has advised doctoral students Dave Sheppard and Jay Schwille whose research involved measurements of water sprays from sprinklers and mist nozzles. At the University of Illinois, Chicago, Prof. Ishwar Puri along with students Anurag Jhalani and Achintya Mukhopadhyay validated the model against slot burner measurements. The purpose of their study was to quantify the effects of flame stretch. At Virginia Tech, Prof. Uri Vandsburger hosted NIST Post-Doc Jason Floyd during his two-year tenure at NIST. Doctoral student Chris Wieczorek performed a series of compartment fire experiments used in part to validate FDS.
His research interests include subgrid-scale models and numerical methods for large-eddy simulati... more His research interests include subgrid-scale models and numerical methods for large-eddy simulation, adaptive mesh refinement, immersed boundary methods, and Lagrangian particle methods.
VTT Tiedotteita - Valtion Teknillinen Tutkimuskeskus
Survivability of ships in case of fire has been studied in the SURSHIP-FIRE research project as a... more Survivability of ships in case of fire has been studied in the SURSHIP-FIRE research project as a part of the SURSHIP cooperation, a coordinated European research program on Maritime safety. The work was performed in four subprojects related to materials used in shipbuilding, fire hazards on board, ship structures, and evacuation in ship conditions. Fire test data of products commonly used in shipbuilding were stored to a free-of-charge accessible database for the use of design engineers. Guidelines were defined for using fire test data in simulation and product development. Procedures for quantitative fire risk analyses of cabins and cabin areas were defined, applicable also to other cases with different features and details. A methodology for defining design fires for various ship spaces was formulated and applied to shops on board as a practical example. The sophisticated simulation and risk analysis tools utilized in the work were the FDS5 fire simulation program with its evacuation module FDS+Evac, the Probabilistic Fire Simulator, and the method of time-dependent event trees. The effects of engine room fires on car deck structures were analysed in detail since the situation was recognised critical for the structural integrity of the ship. Thermal and mechanical analyses of the structures with different dimensions and insulation extents were performed considering both the standard fire curve and the hydrocarbon curve. A survey of specific features of ship evacuation was carried out. Since the use of staircases and the movement of evacuees between decks is an essential part of ship evacuation, a new staircase submodel for the FDS+Evac program was created, verified and validated. The results of the SURSHIP-FIRE project can influence on IMO rules for alternative fire safety design of ships. The contributions of SURSHIP-FIRE are guidelines for using fire test data as input of simulations, a methodology for estimation of design fires, practices for quantitative risk analyses, a summary of critical fire situations for structures, and suggested improvements of the IMO guidelines for evacuation analyses.
Malli rakennettiin käyttäen neuroverkkojen itseorganisoituvia karttoja (SOM), jotka ovat yksi neu... more Malli rakennettiin käyttäen neuroverkkojen itseorganisoituvia karttoja (SOM), jotka ovat yksi neuroverkkojen tyyppi. Neuroverkot ovat epälineaarinen estimointimenetelmä, joiden perusajatus tulee luonnollisista neuroverkoista. Neuroverkkoa opetetaan esimerkkien avulla, ja se oppii muuttujien epälineaariset riip-5. Itseorganisoituvat kartat (SOM)
The reliability of the nuclear power plant safety systems relies strongly on the concept of redun... more The reliability of the nuclear power plant safety systems relies strongly on the concept of redundancy. In some plant designs, cables of two subsystems can exist in the same room. In this work, Monte Carlo fire simulations of this kind of cable tunnel are performed. The goal of these simulations is to estimate the time dependent probabilities of cable failures and other events in case of a cable fire starting from the power cables of one subsystem. The simulations compare consequences with and without an operating sprinkler system.
Electrical cables constitute the major part of the fire loads in nuclear power plants and may als... more Electrical cables constitute the major part of the fire loads in nuclear power plants and may also serve as ignition sources, contributing significantly to the overall risk. In this paper, the numerical methods for describing the thermal degradation of cable component materials are presented. Analytical techniques based on genetic algorithms for estimating the necessary model parameters from the small and bench scale experimental data have been used and the procedure for parameter estimation is reported. As a special topic, the modelling of the fire retardant cable materials is discussed.
Fire Safety Science, 2011
One of the most commonly used materials in electrical cables is flexible PVC. In this work, the e... more One of the most commonly used materials in electrical cables is flexible PVC. In this work, the effects of the modelling decisions and parameter estimation methods on the pyrolysis modelling of two PVC cables were studied. The kinetic and thermal parameters were estimated from TGA and cone calorimeter experiments. The role of the plasticizers was shown to be important for the early HRR. The effects of the reaction path and reaction order were only minor in the TGA results but significant effects were found in the cone calorimeter results, unless a specific set of thermal parameters was estimated. The results show that the thermal parameters estimated for one kinetic model should not be used for another, unless the kinetic models only differ in fuel yields or different pairs of kinetic coefficients with same reaction order.