| 1. |
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| 2. |
- Abbott, Benjamin W., et al.
(författare)
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Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire : an expert assessment
- 2016
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
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| 3. |
- Bal, Nicolas, et al.
(författare)
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Experimental study of radiative heat transfer in a translucent fuel sample exposed to different spectral sources
- 2013
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Ingår i: International Journal of Heat and Mass Transfer. - : Elsevier BV. - 0017-9310 .- 1879-2189. ; 61:1, s. 742-748
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Tidskriftsartikel (refereegranskat)abstract
- Radiative heat transfer to a solid is a key mechanism in fire dynamics, and in-depth absorption is especially of importance for translucent fuels. The sample-heater interaction for radiative heat transfer is experimentally investigated in this study with two different heaters (electric resistance and tungsten lamp) using clear PolyMethylMethAcrylate (PMMA) samples from two different formulations (Plexiglass and Lucite). First, the significant effects of the heater type and operating temperature on the radiative heat transfer are revealed with broadband measurements of transmittance on samples of different thicknesses. Then, the attenuation coefficient in Beer-Lambert's law has been calculated from detailed spectral measurements over the full wavelength range encountered in real fires. The measurements present large spectral heterogeneity. These experimental results and calculation of in-depth absorption are used to explain the reason behind the apparent variation of the fuel absorbance with the sample thickness observed in past studies. The measurement of the spectral intensity emitted by the heaters verifies that the common assumption of blackbody behavior is correct for the electric resistance, whereas the tungsten lamp does not even behave as a greybody. This investigation proofs the necessity of a multi-band radiation model to calculate accurately the fire radiative heat transfer which affects directly the in-depth temperature profiles and hence the pyrolysis process for translucent fuel.
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| 4. |
- Boulet, Pascual, et al.
(författare)
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Radiation emission from a heating coil or a halogen lamp on a semitransparent sample
- 2014
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Ingår i: International Journal of Thermal Sciences. - : Elsevier BV. - 1290-0729. ; 77:March, s. 223-232
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Tidskriftsartikel (refereegranskat)abstract
- The radiation emission of the heating coil of a Cone Calorimeter and the one of the halogen lamp of a Fire Propagation Apparatus have been studied experimentally for varying power settings. These are two standard apparatuses used for fire calorimetry. The objective is to characterize and compare the radiative flux spectrum received by a fuel sample during pyrolysis experiments. The deviation from the standard assumption of black or gray emission is discussed. It is observed that the emission of the heating coil can be approximated well to an ideal blackbody, especially in the infrared range. On the contrary, the halogen lamp emission is more complex, non gray, with an important contribution in the visible and in the near infrared ranges. The flux received by a sample exposed to these emitters is predicted using ray tracing simulations. This shows that the irradiation flux and spectrum from the cone can be accurately calculated if the coil temperature is known. The non Lambertian irradiation flux from the lamp is modeled with a combination of diffuse and collimated intensities, representing the direct emission from the lamp itself and the reflection by the mirror at the rear side. For both emitters, the irradiation is confirmed to be approximately uniform over the surface of a sample 5 cm large (maximum deviation of ±2% on the incident flux). The uniformity decreases for larger samples, but the ratio of the flux at the center to average flux is still 1.04 for standard 10 cm × 10 cm samples under the cone. For illustration purposes, the influence of the spectral characteristics of the emitter is studied in the case of a sample of PMMA, a non gray translucent medium. Using recently published measurements of PMMA absorptivity, the absorbed flux by a 3 cm thick sample is predicted. In the case of an incident flux of 20 kW/m2, the calculated average absorptivity of the sample is 0.91 under the cone, while it is 0.32 under the FPA lamp. These calculations involve absorption data of a virgin sample at room temperature and consequently the numerical results only hold for the initial instants of irradiation. However, the very large differences in radiative behavior show that important discrepancies in the pyrolysis behavior are expected between the two emitters. This might have consequences for fire testing and inter comparisons of flammability results worth further investigation.
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| 5. |
- Boustras, Georgios, et al.
(författare)
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Fires: fund research for citizen safety
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 551:7680, s. 300-300
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Gwynne, Steve M.V., et al.
(författare)
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Roxborough Park Community Wildfire Evacuation Drill : Data Collection and Model Benchmarking
- 2023
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Ingår i: Fire Technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 59:2, s. 879-901
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Tidskriftsartikel (refereegranskat)abstract
- Wildfires are increasing in scale, frequency and longevity, and are affecting new locations as environmental conditions change. This paper presents a dataset collected during a community evacuation drill performed in Roxborough Park, Colorado (USA) in 2019. This is a wildland–urban interface community including approximately 900 homes. Data concerning several aspects of community response were collected through observations and surveys: initial population location, pre-evacuation times, route use, and arrival times at the evacuation assembly point. Data were used as inputs to benchmark two evacuation models that adopt different modelling approaches. The WUI-NITY platform and the Evacuation Management System model were applied across a range of scenarios where assumptions regarding pre-evacuation delays and the routes used were varied according to original data collection methods (and interpretation of the data generated). Results are mostly driven by the assumptions adopted for pre-evacuation time inputs. This is expected in communities with a low number of vehicles present on the road and relatively limited traffic congestion. The analysis enabled the sensitivity of the modelling approaches to different datasets to be explored, given the different modelling approaches adopted. The performance of the models were sensitive to the data employed (derived from either observations or self-reporting) and the evacuation phases addressed in them. This indicates the importance of monitoring the impact of including data in a model rather than simply on the data itself, as data affects models in different ways given the modelling methods employed. The dataset is released in open access and is deemed to be useful for future wildfire evacuation modelling calibration and validation efforts.
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| 7. |
- Heidari, Mohammad, et al.
(författare)
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Probabilistic Study of the Resistance of a Simply-Supported Reinforced Concrete Slab According to Eurocode Parametric Fire
- 2019
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Ingår i: Fire technology. - : Springer Science and Business Media LLC. - 0015-2684 .- 1572-8099. ; 55:4, s. 1377-1404
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Tidskriftsartikel (refereegranskat)abstract
- We present the application of a simple probabilistic methodology to determine the reliability of a structural element exposed to fire when designed following Eurocode 1-1-2 (EC1). Eurocodes are being used extensively within the European Union in the design of many buildings and structures. Here, the methodology is applied to a simply-supported, reinforced concrete slab 180 mm thick, with a standard load bearing fire resistance of 90 min. The slab is subjected to a fire in an office compartment of 420 m2 floor area and 4 m height. Temperature time curves are produced using the EC1 parametric fire curve, which assumes uniform temperature and a uniform burning condition for the fire. Heat transfer calculations identify the plausible worst case scenarios in terms of maximum rebar temperature. We found that a ventilation-controlled fire with opening factor 0.02 m1/2 results in a maximum rebar temperature of 448°C after 102 min of fire exposure. Sensitivity analyses to the main parameters in the EC1 fire curves and in the EC1 heat transfer calculations are performed using a one-at-a-time (OAT) method. The failure probability is then calculated for a series of input parameters using the Monte Carlo method. The results show that this slab has a 0.3% probability of failure when the compartment is designed with all layers of safety in place (detection and sprinkler systems, safe access route, and fire fighting devices are available). Unavailability of sprinkler systems results in a 1% probability of failure. When both sprinkler system and detection are not available in the building, the probability of failure is 8%. This novel study conducts for the first time a probabilistic calculation using the EC1 parametric curve, helping engineers to identify the most critical design fires and the probabilistic resistance assumed in EC1.
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| 8. |
- Kalogeropoulos, Nikolaos, et al.
(författare)
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Design of stochastic trigger boundaries for rural communities evacuating from a wildfire
- 2023
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Ingår i: Fire Safety Journal. - 0379-7112. ; 140
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Tidskriftsartikel (refereegranskat)abstract
- Well-planned evacuation is an effective and often necessary tool to protect life in communities threatened by wildfire. In previous incidents, community evacuations have been called too late resulting in entrapment, such as in Mati, Greece in 2018. The most reliable method to determine the safe time to call an evacuation is through trigger boundaries, perimeters on the landscape surrounding a community where the approaching wildfire is an amount of time away from the community equal to the evacuation time. This paper presents a new tool, k-PERIL, that calculates stochastic trigger boundaries, based on the variability of wildfire behaviour around a community due to the influence of historic wind, weather and vegetation variations on the wildfire. k-PERIL is applied to the rural community of Roxborough Park, Colorado, USA, producing probabilistic trigger boundaries and showing the model's ability to find and quantify areas of elevated uncertainty of evacuation. The concept of uncertainty rosettes is introduced, which show the areas where incoming wildfires cause larger variation to the boundary location because of higher sensitivity to changes in fuel, wind or evacuation. The k-PERIL tool can be used to inform effective evacuation preparation and enhance long term planning, improving community safety and wildfire resilience.
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| 9. |
- Kinateder, Max, et al.
(författare)
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Virtual Reality for Fire Evacuation Research
- 2014
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Ingår i: Federated Conference on Computer Science and Information Systems. - 2300-5963. ; 2, s. 313-321
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Konferensbidrag (refereegranskat)abstract
- Virtual reality (VR) has become a popular approach to study human behavior in fire. The present position paper analyses Strengths, Weaknesses, Opportunities, and Threats (SWOT) of VR as a research tool for human behavior in fire. Virtual environments provide a maximum of experimental control, are easy to replicate, have relatively high ecological validity, and allow safe study of occupant behavior in scenarios that otherwise would be too dangerous. Lower ecological validity compared to field studies, ergonomic aspects, and technical limitations are the main weaknesses of the method. Increasingly realistic simulations and other technological advances provide new opportunities for this relatively young method. In this position paper, we argue that VR is a promising complementary laboratory tool in the quest to understand human behavior in fire and to improve fire safety.
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| 10. |
- Kuligowski, E., et al.
(författare)
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Evacuation modelling for bushfire : the WUI-NITY simulation platform
- 2022
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Ingår i: Australian Journal of Emergency Management. - 1324-1540. ; 37:4, s. 40-43
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Tidskriftsartikel (refereegranskat)abstract
- The number of people who live in bushfire-prone areas around the world is growing. In Australia, in the states of Victoria and New South Wales, over 1.5 million people live in areas rated as high to extreme bushfire risk in (SGS Economics and Planning 2019). As effects of climate change increase the size and severity of bushfires, and a greater number of people move into these at-risk areas, there is a growing imperative to understand the likely evacuation outcomes of bushfireprone communities under various fire scenarios. This paper introduces a freely available simulation platform called WUI-NITY that can be used by evacuation planners and decisionmakers to forecast evacuation behaviour within affected areas, and in turn, better prepare for and respond to future bushfire events.
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| 11. |
- McNamee, Margaret, et al.
(författare)
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IAFSS agenda 2030 for a fire safe world
- 2019
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Ingår i: Fire Safety Journal. - : Elsevier BV. - 0379-7112. ; 110
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Tidskriftsartikel (refereegranskat)abstract
- The International Association of Fire Safety Science (IAFSS) is comprised of members from some 40 countries. This paper presents the Association's thinking, developed by the Management Committee, concerning pressing research needs for the coming 10 years presented as the IAFSS Agenda 2030 for a Fire Safe World. The research needs are couched in terms of two broad Societal Grand Challenges: (1) climate change, resiliency and sustainability and (2) population growth, urbanization and globalization. The two Societal Grand Challenges include significant fire safety components, that lead both individually and collectively to the need for a number of fire safety and engineering research activities and actions. The IAFSS has identified a list of areas of research and actions in response to these challenges. The list is not exhaustive, and actions within actions could be defined, but this paper does not attempt to cover all future needs.
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| 12. |
- Mitchell, Harry, et al.
(författare)
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Integrating wildfire spread and evacuation times to design safe triggers : Application to two rural communities using PERIL model
- 2023
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Ingår i: Safety Science. - : Elsevier BV. - 0925-7535. ; 157
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Tidskriftsartikel (refereegranskat)abstract
- The hazards posed by a wildfire increase significantly when it approaches the wildland–urban interface. Evacuation of rural communities is frequently considered by local authorities and residents. In this context, evacuation triggers are locations that when reached by the wildfire indicate it is time to evacuate. Triggers are often arbitrarily defined via identifiable landmarks, do not include a safety factor, and do not account for fire spread or how long the evacuation takes. Ill-designed triggers may not safely inform decision making. It is necessary to create evacuation triggers that take into account both how a fire spreads towards the community, and how a community evacuates. This paper outlines a framework for developing triggers through the coupling of wildfire and evacuation models. We implement the previous theory of Cova et al. (2005) and others on triggers into a tool known as PERIL for generating trigger perimeters around a community, using the fire spread model FARSITE. A safety factor is included to address uncertainties in the wildfire or evacuation calculations. PERIL was applied to two real communities for the Swinley forest community (UK), and Roxborough Park community (USA). These communities were chosen because of previous work studying their actual evacuations. PERIL, which is available in open source, can be applied to inform safer strategies for to protect rural communities threatened by wildfires.
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| 13. |
- Ronchi, Enrico, et al.
(författare)
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An open multi-physics framework for modelling wildland-urban interface fire evacuations
- 2019
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Ingår i: Safety Science. - : Elsevier BV. - 0925-7535. ; 118, s. 868-880
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Tidskriftsartikel (refereegranskat)abstract
- Fire evacuations at wildland-urban interfaces (WUI) pose a serious challenge to the emergency services, and are a global issue affecting thousands of communities around the world. This paper presents a multi-physics framework for the simulation of evacuation in WUI wildfire incidents, including three main modelling layers: wildfire, pedestrians, and traffic. Currently, these layers have been mostly modelled in isolation and there is no comprehensive model which accounts for their integration. The key features needed for system integration are identified, namely: consistent level of refinement of each layer (i.e. spatial and temporal scales) and their application (e.g. evacuation planning or emergency response), and complete data exchange. Timelines of WUI fire events are analysed using an approach similar to building fire engineering (available vs. required safe egress times for WUI fires, i.e. WASET/WRSET). The proposed framework allows for a paradigm shift from current wildfire risk assessment and mapping tools towards dynamic fire vulnerability mapping. This is the assessment of spatial and temporal vulnerabilities based on the wildfire threat evolution along with variables related to the infrastructure, population and network characteristics. This framework allows for the integration of the three main modelling layers affecting WUI fire evacuation and aims at improving the safety of WUI communities by minimising the consequences of wildfire evacuations.
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| 14. |
- Ronchi, Enrico, et al.
(författare)
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e-Sanctuary: open multi-physics framework for modelling wildfire urban evacuation
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The number of evacuees worldwide during wildfire keep rising, year after year. Fire evacuations at the wildland-urban interfaces (WUI) pose a serious challenge to fire and emergency services and are a global issue affecting thousands of communities around the world. But to date, there is a lack of comprehensive tools able to inform, train or aid the evacuation response and the decision making in case of wildfire. The present work describes a novel framework for modelling wildfire urban evacuations. The framework is based on multi-physics simulations that can quantify the evacuation performance. The work argues that an integrated approached requires considering and integrating all three important components of WUI evacuation, namely: fire spread, pedestrian movement, and traffic movement. The report includes a systematic review of each model component, and the key features needed for the integration into a comprehensive toolkit.
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| 15. |
- Ronchi, Enrico, et al.
(författare)
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Framework for an integrated simulation system for Wildland-Urban Interface fire evacuation
- 2017
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Ingår i: ; , s. 119-134
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The negative consequences of fires in case of evacuation in wildland-urban interfaces (WUI) are a global issue that affect many communities around the world. To date, there is a lack of a comprehensive tool able to aid decision making in case of WUI fire evacuation. To address this issue, this paper presents a design specification for a simulation system for the quantification of evacuation performance in case of Wildland-Urban Interface fire incidents. This includes three main modelling components, namely 1) fire spread, 2) pedestrian movement and 3) traffic. To date, the development and use of modelling tools for disaster assessment have mostly been performed in isolation (i.e., with limited coupling between fire models, pedestrian models and traffic models). This paper presents the results of the review of these three core modelling components and the requirements for their integration into an integrated toolkit. A systematic approach for the review has been developed and applied with the goal of identifying the key features needed for the integration. This framework aims at assessing evacuation performance for both evacuation planning as well as decision support applications. Such a framework might be used to predict how the evacuation develops based on different fire conditions and according to different evacuation decisions. This paper presents some of the key findings of the modelling framework specification, namely: 1) the level of granularity of each type of model in relation to the scenario (i.e. spatial and temporal scale) and their applications (for all layers under consideration) and 2) the required data exchange among different models.
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| 16. |
- Uadiale, Solomon, et al.
(författare)
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Overview of problems and solutions in fire protection engineering of wind turbines
- 2014
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Ingår i: Fire Safety Science. - : International Association for Fire Safety Science. ; , s. 983-995
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Konferensbidrag (refereegranskat)abstract
- The wind energy industry is one of today's leading industries in the renewable energy sector, providing an affordable and sustainable energy solution. However, the wind industry faces a number of challenges, one of which is fire and that can cast a shadow on its green credentials. The three elements of the fire triangle, fuel (oil and polymers), oxygen (wind) and ignition (electric, mechanical and lighting) are represent and confined to the small and closed compartment of the turbine nacelle. Moreover, once ignition occurs in a turbine, the chances of externally fighting the fire are very slim due to the height of the nacelle and the often remote location of the wind farm. Instances of reports about fires in wind farms are increasing, yet the true extent of the impact of fires on the energy industry on a global scale is impossible to assess. Sources of information are incomplete, biased, or contain non-publically available data. The poor statistical records of wind turbine fires are a main cause of concern and hinder any research effort in this field. This paper aims to summarise the current state of knowledge in this area by presenting a review of the few sources which are available, in order to quantify and understand the fire problem in wind energy. We have found that fire is the second leading cause of catastrophic accidents in wind turbines (after blade failure) and accounts for 10 to 30% of the reported turbine accidents of any year since 1980's. In 90% of the cases, the fire leads to a total loss of the wind turbine, or at least a downtime that results in the accumulation of economic losses. The main causes of fire ignition in wind turbines are (in decreasing order of importance): lighting strike, electrical malfunction, mechanical malfunction, and maintenance. Due to the many flammable materials used in a wind turbine (eg. fiberglass reinforced polymers, foam insulation, cables) and the large oil storage used for lubrication of mechanical components, the fuel load in a turbine nacelle is commonly very large. The paper finishes with an overview of the passive and active protection options and the economics (costs, revenue and insurance) of wind turbines to put in context the value of a loss turbine compared to the cost and options of fire protection. We hope that this paper will encourage the scientific community to pursue a proper understanding of the problem and its scale, allowing the development of the most appropriate fire protection engineering solutions.
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| 17. |
- Wahlqvist, Jonathan, et al.
(författare)
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The simulation of wildland-urban interface fire evacuation : The WUI-NITY platform
- 2021
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Ingår i: Safety Science. - : Elsevier BV. - 0925-7535. ; 136
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Tidskriftsartikel (refereegranskat)abstract
- Wildfires are a significant safety risk to populations adjacent to wildland areas, known as the wildland-urban interface (WUI). This paper introduces a modelling platform called WUI-NITY. The platform is built on the Unity3D game engine and simulates and visualises human behaviour and wildfire spread during an evacuation of WUI communities. The purpose of this platform is to enhance the situational awareness of responders and residents during evacuation scenarios by providing information on the dynamic evolution of the emergency. WUI-NITY represents current and predicted conditions by coupling the three key modelling layers of wildfire evacuation, namely the fire, pedestrian, and traffic movement. This allows predictions of evacuation behaviour over time. The current version of WUI-NITY demonstrates the feasibility and advantages of coupling the modelling layers. Its wildfire modelling layer is based on FARSITE, the pedestrian layer implements a dedicated pedestrian response and movement model, and the traffic layer includes a traffic evacuation model based on the Lighthill-Whitham-Richards model. The platform also includes a sub-model called PERIL that designs the spatial location of trigger buffers. The main contribution of this work is in the development of a modular and model-agnostic (i.e., not linked to a specific model) platform with consistent levels of granularity (allowing a comparable modelling resolution in the representation of each layer) in all three modelling layers. WUI-NITY is a powerful tool to protect against wildfires; it can enable education and training of communities, forensic studies of past evacuations and dynamic vulnerability assessment of ongoing emergencies.
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