Efficient simulation of wildfire spread on an irregular grid

2008 ◽  
Vol 17 (5) ◽  
pp. 614 ◽  
Author(s):  
Paul Johnston ◽  
Joel Kelso ◽  
George J. Milne
Keyword(s):  
Discrete Event ◽  
Front Propagation ◽  
Fire Spread ◽  
Computational Method ◽  
Shape Distortion ◽  
Irregular Grid ◽  
Simulation Techniques ◽  
Fire Front ◽  
Wildfire Simulation ◽  
Propagation Methods

A cell-based wildfire simulator that uses an irregular grid is presented. Cell-based methods are simpler to implement than fire front propagation methods but have traditionally been plagued by fire shape distortion caused by the fire only being able to travel in certain directions. Using an irregular grid randomises the error introduced by the grid, so that the shape of simulated fire spread is independent of the direction of the wind with respect to the underlying grid. The cell-based fire spread simulator is implemented using discrete event simulation, which is a much more efficient computational method than conventional wildfire simulation techniques because computing resources are not used in repeatedly computing small updates to parts of the fire whose dynamics change infrequently, namely those areas of a fire that move slowly. The resulting simulator is comparable in accuracy with traditional fire front propagation schemes but is much faster and can therefore be used as an engine for fire simulation applications that require large numbers of simulations, such as in the role of a risk analysis engine.

A simple model for wind effects of burning structures and topography on wildland–urban interface surface-fire propagation

2009 ◽  
Vol 18 (3) ◽  
pp. 290 ◽  
Author(s):  
Ronald G. Rehm ◽  
William (Ruddy) Mell
Keyword(s):  
Simple Model ◽  
Front Propagation ◽  
Ground Level ◽  
Fire Spread ◽  
Wildland Urban Interface ◽  
Fire Propagation ◽  
Interface Surface ◽  
Fire Front ◽  
Ground Slope ◽  
Structural Fires

The present paper presents a simple model to demonstrate the effect on grass-fire propagation of the winds induced by structural fires in a wildland–urban interface setting. The model combines an empirical formula for wind-driven grass-fire spread and a physics-based analytical solution to the Euler equations to determine the ground-level wind produced by the burning structure. The scaling of the wind is based on the heat release rate of the structural fire as well as other parameters. Also considered are an ambient wind and a topographical wind, assumed to be proportional to the ground slope. Data on grass and structure fires required by the model are discussed. Fire front propagation predicted by this model is illustrated by three examples: a front passing a single burning structure on flat terrain, a front passing a burning structure on a hill, and a front passing several burning structures. The model predicts that a fire front will be accelerated toward the burning structure upon approach and decelerated after passing the structure. Several burning structures multiply the effects of an individual burning structure.

scholarly journals A Coupled Atmosphere-Fire Model: Role of the Convective Froude Number and Dynamic Fingering at the Fireline

1996 ◽  
Vol 6 (4) ◽  
pp. 177 ◽  
Author(s):  
TL Clark ◽  
MA Jenkins ◽  
JL Coen ◽  
DR Packham
Keyword(s):  
Forest Fire ◽  
Fire Behavior ◽  
Atmospheric Model ◽  
Fire Spread ◽  
Atmospheric Conditions ◽  
Fire Model ◽  
Eucalyptus Forest ◽  
Fire Front ◽  
Forest Fire Model ◽  
Wildfire Simulation

A numerical atmospheric model is coupled with a simple dry eucalyptus forest fire model to create a wildfire simulation model. This is used to show how certain atmospheric conditions can lead to commonly observed forest fire behavior. Using short line fires, simulations show that with moderate winds, the fire line interacts with the updraft ahead of it causing the fire line to curve forward into a conical shape. Other experiments show that when ambient winds change with height, a pair of rotating updrafts at the curved fire front can touch down within the fire and break up the fire line. We also demonstrate 'dynamic fingering', in which the rotating columns near the fire front intensify to tornado strength and can result in rapid and strong increases in the fire spread rate.

A comparison of level set and marker methods for the simulation of wildland fire front propagation

2016 ◽  
Vol 25 (2) ◽  
pp. 229 ◽  
Author(s):  
Anthony S. Bova ◽  
William E. Mell ◽  
Chad M. Hoffman
Keyword(s):  
Level Set ◽  
Wildland Fire ◽  
Front Propagation ◽  
Fire Spread ◽  
Fire Dynamics ◽  
Surface Fire ◽  
Fire Dynamics Simulator ◽  
Fire Front ◽  
The Difference ◽  
Moving Front

Simulating an advancing fire front may be achieved within a Lagrangian or Eulerian framework. In the former, independently moving markers are connected to form a fire front, whereas in the latter, values representing the moving front are calculated at points within a fixed grid. Despite a mathematical equivalence between the two methods, it is not clear that both will produce the same results when implemented numerically. Here, we describe simulations of fire spread created using a level set Eulerian approach (as implemented in the wildland–urban interface fire dynamics simulator, WFDS) and a marker method (as implemented in FARSITE). Simulations of surface fire spread, in two different fuels and over domains of increasing topographical complexity, are compared to evaluate the difference in outcomes between the two models. The differences between the results of the two models are minor, especially compared with the uncertainties inherent in the modelling of fire spread.

scholarly journals Ignition Vulnerabilities of Combustibles around Houses to Firebrand Showers: Further Comparison of Experiments

2021 ◽  
Vol 13 (4) ◽  
pp. 2136
Author(s):  
Sayaka Suzuki ◽  
Samuel L. Manzello
Keyword(s):  
Experimental Data ◽  
Thermal Radiation ◽  
Driving Force ◽  
Fire Spread ◽  
Significant Problem ◽  
Next Generation ◽  
Similar Time ◽  
Comparison Of Experiments ◽  
Fire Front ◽  
Wui Fires

Wildland fires and wildland urban-interface (WUI) fires have become a significant problem in recent years. The mechanisms of home ignition in WUI fires are direct flame contact, thermal radiation, and firebrand attack. Out of these three fire spread factors, firebrands are considered to be a main driving force for rapid fire spread as firebrands can fly far from the fire front and ignite structures. The limited experimental data on firebrand showers limits the ability to design the next generation of communities to resist WUI fires to these types of exposures. The objective of this paper is to summarize, compare, and reconsider the results from previous experiments, to provide new data and insights to prevent home losses from firebrands in WUI fires. Comparison of different combustible materials around homes revealed that wood decking assemblies may be ignited within similar time to mulch under certain conditions.

Fine-Scale Fire Spread in Pine Straw

Fire ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 69
Author(s):  
Daryn Sagel ◽  
Kevin Speer ◽  
Scott Pokswinski ◽  
Bryan Quaife
Keyword(s):  
Fire Spread ◽  
Small Scale ◽  
Natural Setting ◽  
Fine Scale ◽  
Prescribed Burn ◽  
Fire Dynamics ◽  
Rate Of Spread ◽  
Scale Models ◽  
Fire Front ◽  
Visible Images

Most wildland and prescribed fire spread occurs through ground fuels, and the rate of spread (RoS) in such environments is often summarized with empirical models that assume uniform environmental conditions and produce a unique RoS. On the other hand, representing the effects of local, small-scale variations of fuel and wind experienced in the field is challenging and, for landscape-scale models, impractical. Moreover, the level of uncertainty associated with characterizing RoS and flame dynamics in the presence of turbulent flow demonstrates the need for further understanding of fire dynamics at small scales in realistic settings. This work describes adapted computer vision techniques used to form fine-scale measurements of the spatially and temporally varying RoS in a natural setting. These algorithms are applied to infrared and visible images of a small-scale prescribed burn of a quasi-homogeneous pine needle bed under stationary wind conditions. A large number of distinct fire front displacements are then used statistically to analyze the fire spread. We find that the fine-scale forward RoS is characterized by an exponential distribution, suggesting a model for fire spread as a random process at this scale.

scholarly journals ABWiSE v1.0: Toward and Agent-Based Approach to Simulating Wildfire Spread

2021 ◽  
Author(s):  
Jeffrey Katan ◽  
Liliana Perez
Keyword(s):  
Human Life ◽  
Simulation Models ◽  
Empirical Models ◽  
Physical Models ◽  
Fire Behaviour ◽  
Agent Based ◽  
Agent Based Modelling ◽  
Fire Front ◽  
Wildfire Simulation ◽  
Behaviour Simulation

Abstract. Wildfires are a complex phenomenon emerging from interactions between air, heat, and vegetation, and while they are an important component of many ecosystems’ dynamics, they pose great danger to those ecosystems, and human life and property. Wildfire simulation models are an important research tool that help further our understanding of fire behaviour and can allow experimentation without recourse to live fires. Current fire simulation models fit into two general categories: empirical models and physical models. We present a new modelling approach that uses agent-based modelling to combine the complexity found in physical models with the ease of computation of empirical models. Our model represents the fire front as a set of moving agents that respond to, and interact with, vegetation, wind, and terrain. We calibrate the model using two simulated fires and one real fire, and validate the model against another real fire and the interim behaviour of the real calibration fire. Our model successfully replicates these fires, with a Figure of Merit on par with simulations by the Prometheus simulation model. Our model is a stepping-stone in using agent-based modelling for fire behaviour simulation, as we demonstrate the ability of agent-based modelling to replicate fire behaviour through emergence alone.

scholarly journals Physical parametrisation of fire-spotting for operational fire spread models: response analysis with a model based on the Level Set Method

2018 ◽  
Author(s):  
Inderpreet Kaur ◽  
Anton Butenko ◽  
Gianni Pagnini
Keyword(s):  
Level Set Method ◽  
Level Set ◽  
Discrete Event ◽  
Fire Spread ◽  
Response Analysis ◽  
System Specification ◽  
Time Step ◽  
Processing Scheme ◽  
Model Based ◽  
The Many

Abstract. Fire-spotting is often responsible for a dangerous flare up in the wildfire and causes secondary ignitions isolated from the primary fire zone leading to perilous situations. In this paper a complete physical parametrisation of fire-spotting is presented within a formulation aimed to include random processes into operational fire spread models. This formulation can be implemented into existing operational models as a post-processing scheme at each time step, without calling for any major changes in the original framework. In particular, the efficacy of this formulation has already been shown for wildfire simulators based on an Eulerian moving interface method, namely the Level Set Method (LSM) that forms the baseline of the operational software WRF-SFIRE, and for wildfire simulators based on a Lagrangian front tracking technique, namely the Discrete Event System Specification (DEVS) that forms the baseline of the operational software FOREFIRE. The simple and computationally less expensive parametrisation includes the important parameters necessary for describing the landing behavior of the firebrands. The results from different simulations with a simple model based on the LSM highlight the response of the parametrisation to varying fire intensities, wind conditions and different firebrand radii. The contribution of the firebrands towards increasing the fire perimeter varies according to different concurrent conditions and the simulation results prove to be in agreement with the physical processes. Among the many rigorous approaches available in literature to model the firebrand transport and distribution, the approach presented here proves to be simple yet versatile for application to operational fire spread models.

Laboratory fire spread analysis using visual and infrared images

2006 ◽  
Vol 15 (2) ◽  
pp. 179 ◽  
Author(s):  
J. Ramiro Martínez-de Dios ◽  
Jorge C. André ◽  
João C. Gonçalves ◽  
Begoña Ch. Arrue ◽  
Aníbal Ollero ◽  
...  
Keyword(s):  
Graphical Model ◽  
Fire Spread ◽  
Rate Of Spread ◽  
Virtual View ◽  
Fire Front ◽  
Computer Based ◽  
Front Shape ◽  
Processing Techniques ◽  
Spread Analysis ◽  
Base Width

This paper presents an experimental method using computer-based image processing techniques of visual and infrared movies of a propagating fire front, taken from one or more cameras, to supply the time evolutions of the fire front shape and position, flame inclination angle, height, and base width. As secondary outputs, it also provides the fire front rate of spread and a 3D graphical model of the fire front that can be rendered from any virtual view. The method is automatic and non-intrusive, has space–time resolution close to continuum and can be run in real-time or deferred modes. It is demonstrated in simple laboratory experiments in beds of pine needles set upon an inclinable burn table, with point and linear ignitions, but can be extended to open field situations.

The FireFlux II experiment: a model-guided field experiment to improve understanding of fire–atmosphere interactions and fire spread

2019 ◽  
Vol 28 (4) ◽  
pp. 308 ◽  
Author(s):  
Craig B. Clements ◽  
Adam K. Kochanski ◽  
Daisuke Seto ◽  
Braniff Davis ◽  
Christopher Camacho ◽  
...  
Keyword(s):  
Fire Spread ◽  
Model Systems ◽  
Large Set ◽  
Tall Grass ◽  
Combustion Gases ◽  
Tall Grass Prairie ◽  
Fire Front ◽  
Air Chemistry ◽  
Atmosphere Model ◽  
Behaviour Data

The FireFlux II experiment was conducted in a tall grass prairie located in south-east Texas on 30 January 2013 under a regional burn ban and high fire danger conditions. The goal of the experiment was to better understand micrometeorological aspects of fire spread. The experimental design was guided by the use of a coupled fire–atmosphere model that predicted the fire spread in advance. Preliminary results show that after ignition, a surface pressure perturbation formed and strengthened as the fire front and plume developed, causing an increase in wind velocity at the fire front. The fire-induced winds advected hot combustion gases forward and downwind of the fire front that resulted in acceleration of air through the flame front. Overall, the experiment collected a large set of micrometeorological, air chemistry and fire behaviour data that may provide a comprehensive dataset for evaluating and testing coupled fire–atmosphere model systems.

Optimal Tolerance Allocation of Automotive Pneumatic Control Valves Based on Product and Process Simulations

2006 ◽  
Author(s):  
Naesung Lyu ◽  
Amane Shimura ◽  
Kazuhiro Saitou
Keyword(s):  
Product Quality ◽  
Production Cost ◽  
Radial Basis Function Network ◽  
Discrete Event ◽  
Computational Method ◽  
Tolerance Allocation ◽  
Production Volume ◽  
Pneumatic Control ◽  
Multi Objective ◽  
Trade Offs

This paper discusses a computational method for optimally allocating dimensional tolerances for an automotive pneumatic control valve. Due to the large production volume, costly tight tolerances should be allocated only to the dimensions that have high influence to the quality. Given a parametric geometry of a valve, the problem is posed as a multi-objective optimization with respect to product quality and production cost. The product quality is defined as 1) the deviation from the nominal valve design in the linearity of valve stroke and fluidic force, and 2) the difference in fluidic force with and without cavitation. These quality measures are estimated by using Monte Carlo simulation on a Radial-Basis Function Network (RBFN) trained with computational fluid dynamics (CFD) simulation of the valve operation. The production cost is estimated by the tolerance-cost relationship obtained from the discrete event simulations of valve production process. A multi-objective genetic algorithm is utilized to generate Pareto optimal tolerance allocations with respect to these objectives, and alternative tolerance allocations are proposed considering the trade-offs among multiple objectives.

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