scholarly journals Laboratory experiment of fire spread between two informal settlement dwellings

2022 ◽  
Vol 171 ◽  
pp. 107195
Author(s):  
Yu Wang ◽  
Mohamed Beshir ◽  
Rory Hadden ◽  
Antonio Cicione ◽  
Michal Krajcovic ◽  
...  
Keyword(s):  
Laboratory Experiment ◽  
Informal Settlement ◽  
Fire Spread

scholarly journals Determination of Critical Separation Distance Between Dwellings in Informal Settlements Fire

2021 ◽  
Author(s):  
Yu Wang ◽  
Lesley Gibson ◽  
Mohamed Beshir ◽  
David Rush
Keyword(s):  
Heat Flux ◽  
Informal Settlement ◽  
Informal Settlements ◽  
Fire Risk ◽  
Fire Spread ◽  
Separation Distance ◽  
Flame Length ◽  
Critical Distance ◽  
Fire Disaster ◽  
Critical Separation

AbstractApproximately one billion people across the globe are living in informal settlements with a large potential fire risk. Due to the high dwelling density, a single informal settlement dwelling fire may result in a very serious fire disaster leaving thousands of people homeless. In this work, a simple physics-based theoretical model was employed to assess the critical fire separation distance between dwellings. The heat flux and ejected flame length were obtained from a full-scale dwelling tests with ISO 9705 dimension (3.6 m × 2.4 m × 2.4 m) to estimate the radiation decay coefficient of the radiation heat flux away from the open door. The ignition potential of combustible materials in adjacent dwellings are analyzed based on the critical heat flux from cone calorimeter tests. To verify the critical distance in real informal settlement fire, a parallel method using aerial photography within geographic information systems (GIS), was employed to determine the critical separation distances in four real informal settlement fires of 2014–2015 in Masiphumelele, Cape Town, South Africa. The fire-spread distances were obtained as well through the real fires. The probabilistic analysis was conducted by Weibull distribution and logistic regression, and the corresponding separation distances were given with different fire spread probabilities. From the experiments with the assumption of no interventions and open doors and windows, it was established that the heat flux would decay from around 36 kW/m2 within a distance of 1.0 m to a value smaller than 5 kW/m2 at a distance of 4.0 m. Both experiments and GIS results agree well and suggest the ignition probabilities at distances of 1.0 m, 2.0 m and 3.0 m are 97%, 52% and 5% respectively. While wind is not explicitly considered in the work, it is implicit within the GIS analyses of fire spread risk, therefore, it is reasonable to say that there is a relatively low fire spread risk at distances greater than 3 m. The distance of 1.0 m in GIS is verified to well and conservatively predict the fire spread risk in the informal settlements.

scholarly journals A preliminary investigation to develop a semi-probabilistic model of informal settlement fire spread using B-RISK

2020 ◽  
pp. 103115 ◽  
Author(s):  
Antonio Cicione ◽  
Colleen Wade ◽  
Michael Spearpoint ◽  
Lesley Gibson ◽  
Richard Walls ◽  
...  
Keyword(s):  
Probabilistic Model ◽  
Informal Settlement ◽  
Preliminary Investigation ◽  
Fire Spread

Preliminary Study of Fire Spread in Cities and Forests, Using PMMA Specimen as a Fuel in CFD Simulations

2009 ◽  
Author(s):  
Koyu Satoh ◽  
Naian Liu ◽  
Qiong Liu ◽  
K. T. Yang
Keyword(s):  
Laboratory Experiment ◽  
Forest Fires ◽  
Three Dimensional ◽  
Fire Spread ◽  
Weather Data ◽  
Strong Wind ◽  
Cfd Simulations ◽  
Worst Case ◽  
Fire Propagation ◽  
Fire Spreading

It is important to examine the behavior of forest fires and city fires to mitigate the property damages and victims by fires. There have been many previous studies on forest fires where the fire spreading patterns were investigated, utilizing artificial satellite pictures of forest fires, together with the use of corresponding weather data and GIS data. On the other hand, large area city fires are very scarce in the world, particularly in modern cities where high-rise concrete buildings are constructed with sufficient open spaces. Thus, the examples of city fires to be referred are few and detailed investigations of city fires are limited. However, there have still been existing old cities where traditional houses built with flammable material such as wood, maybe historically important, only separated with very small open spacing. Fires may freely spread in those cities, once a big earthquake happens there and then water supply for the fire brigade is damaged in the worst case along with the effect of strong wind. There are some fundamental differences between the forest fires and city fires, as the fuel may distribute either continuously or discretely. For instance, in forest fires, the dead fallen leaves, dry grasses and trees are distributed continuously on the ground, while the wooden houses in cities are discretely distributed with some separation of open spacing, such as roads and gardens. Therefore, the wooden houses neighboring the burning houses with some separation are heated by radiation and flames to elevate the temperatures, thus causing the ignition, and finally reaching a large city fire. The authors have studied the forest fire spread and are planning to start a laboratory experiment of city fire spreading. In the preliminary investigation, a numerical study is made to correlate with the laboratory experiment of city fire propagation, utilizing the three-dimensional CFD simulations. Based on the detailed experimental analysis, the authors are attempting to modify the three dimensional CFD code to predict the forest fires and city fires more precisely, taking into account the thermal heating and ignition processes. In this study, some fundamental information on the city fire propagation has been obtained, particularly to know the safe open spacing distances between the houses in the cities and also the wind speed.

Large-scale informal settlement experiment considering fire spread under opposed wind flow conditions

2021 ◽  
Author(s):  
Richard Walls ◽  
Charles Kahanji ◽  
Natalia Flores Quiroz ◽  
Antonio Cicione ◽  
Lesley Gibson ◽  
...  
Keyword(s):  
Large Scale ◽  
Informal Settlement ◽  
Fire Spread ◽  
Wind Flow ◽  
Flow Conditions ◽  
Settlement Experiment

scholarly journals Experimental and Numerical Study for the Effect of Horizontal Openings on the External Plume and Potential Fire Spread in Informal Settlements

2021 ◽  
Vol 11 (5) ◽  
pp. 2380
Author(s):  
Mohamed Beshir ◽  
Karim Omar ◽  
Felipe Roman Centeno ◽  
Samuel Stevens ◽  
Lesley Gibson ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Heat Flux ◽  
Computational Fluid Dynamics ◽  
Radiative Heat ◽  
Numerical Study ◽  
Informal Settlement ◽  
Informal Settlements ◽  
Fire Spread ◽  
Heat Fluxes ◽  
Fuel Load

According to recent UN reports, it is estimated that more than one billion people live in informal settlements globally, exposing them to a large potential fire risk. In previous research, it was found that the main fire spread mechanism between dwellings is the external flaming (plume) and radiative heat fluxes from the vertical openings at the dwelling of origin to the surroundings. In this paper, an experimental and numerical study was conducted to quantify the effect of adding horizontal roof openings to the design of informal settlement dwellings to reduce the fire spread risk by decreasing the length of flames and radiation from the external plumes at the vertical openings. In total, 19 quarter scale ISO-9705 compartment fire experiments were conducted using an identical fuel load (80 MJ/m2) of polypropylene and were used to validate a physical computational fluid dynamics model for future studies. Five different total horizontal openings areas (0.0025, 0.01, 0.04, 0.09, and 0.16 m2) were investigated using two horizontal openings designs: (1) four square openings at the four corners of the compartment and (2) one slot cut at the middle of the compartment. It was found that adding horizontal openings decreased the average heat flux measured at the door by up to 65% and 69% for corner and slot cases, respectively. Heat flux reductions were achieved at opening areas as low as 0.01 m2 for slot cases, whereas reductions were only achieved at areas of at least 0.09 m2 for corner cases. The Computational Fluid Dynamics (CFD) model was validated using the experimental results. It successfully captured the main fire dynamics within the compartment in addition to the values of the external radiative heat flux. Further, a new empirical ventilation factor was generated to describe the flow field through both openings configurations which showed strong coupling with the inlet mass of fresh air to the compartment.

scholarly journals Towards the Development of a Probabilistic Approach to Informal Settlement Fire Spread Using Ignition Modelling and Spatial Metrics

Fire ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 67
Author(s):  
Antonio Cicione ◽  
Lesley Gibson ◽  
Colleen Wade ◽  
Michael Spearpoint ◽  
Richard Walls ◽  
...  
Keyword(s):  
Informal Settlement ◽  
Current Model ◽  
Probabilistic Approach ◽  
Fire Spread ◽  
Full Scale ◽  
Spread Rate ◽  
Spatial Metrics ◽  
Wind Speeds ◽  
Fire Scenarios ◽  
Potential Applications

Large conflagrations of informal settlements occur regularly, leaving thousands of people homeless daily and taking tens of thousands of lives annually. Over the past few years, a large amount of data has been collected from a number of full-scale informal settlement fire experiments. This paper uses that data with a semi-probabilistic fire model previously proposed by the authors, to illustrate the potential applications of the fire spread method proposed. The current model is benchmarked against a 20-dwelling full-scale informal settlement fire experiment, and the effects of the (a) ignition criteria, (b) wind direction, and (c) wind speeds on the predicted fire spread rates are investigated through the use of a parametric study. Colour maps of the fire spread rates and patterns are then used to visually interpret the effects of different types of fire scenarios and fire breaks. Finally, the fire spread capability within B-RISK is used to derive a linear equation for the potential fire spread rate as a function of the settlement spatial metrics (e.g., density and distance to nearest neighbour). To further illustrate the potential application of this work, the fire spread rate equation is then applied across the whole of Cape Town, South Africa, to show the 10 informal settlement areas most at “risk” of large conflagrations.

Experimental study of fire spread between multiple full scale informal settlement dwellings

2019 ◽  
Vol 105 ◽  
pp. 19-27 ◽  
Author(s):  
Antonio Cicione ◽  
Richard S. Walls ◽  
Charles Kahanji
Keyword(s):  
Experimental Study ◽  
Informal Settlement ◽  
Fire Spread ◽  
Full Scale
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