Evaluation of the ability of fire dynamic simulator to simulate positive pressure ventilation in the laboratory and practical scenarios

Kerber, Stephen

doi:10.6028/nist.ir.7315

Cited by 9 publications

(8 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Fire Dynamics Simulator (FDS) [51], which is an open-source fire simulation developed by the U.S. National Institute of Standards and Technology (NIST), has proven its reliability in previous studies. The simulated data of the FDS, in which the model is finely structured, showed errors within 10% of the actual fire data [52,53,54]. We used the FDS to generate fires in a virtual environment to obtain temperature, humidity, and gas sensor data.…”

Section: Discussionmentioning

confidence: 99%

Dependable Fire Detection System with Multifunctional Artificial Intelligence Framework

Park

Lee

Yun

et al. 2019

Sensors

View full text Add to dashboard Cite

A fire detection system requires accurate and fast mechanisms to make the right decision in a fire situation. Since most commercial fire detection systems use a simple sensor, their fire recognition accuracy is deficient because of the limitations of the detection capability of the sensor. Existing proposals, which use rule-based algorithms or image-based machine learning can hardly adapt to the changes in the environment because of their static features. Since the legacy fire detection systems and network services do not guarantee data transfer latency, the required need for promptness is unmet. In this paper, we propose a new fire detection system with a multifunctional artificial intelligence framework and a data transfer delay minimization mechanism for the safety of smart cities. The framework includes a set of multiple machine learning algorithms and an adaptive fuzzy algorithm. In addition, Direct-MQTT based on SDN is introduced to solve the traffic concentration problems of the traditional MQTT. We verify the performance of the proposed system in terms of accuracy and delay time and found a fire detection accuracy of over 95%. The end-to-end delay, which comprises the transfer and decision delays, is reduced by an average of 72%.

show abstract

Section: Discussionmentioning

confidence: 99%

Dependable Fire Detection System with Multifunctional Artificial Intelligence Framework

Park

Lee

Yun

et al. 2019

Sensors

View full text Add to dashboard Cite

show abstract

“…However, the main purpose is still fulfilled, as a great amount of air is forced inside the apartment. The inflow boundary is wider than the door to be sure that its flow covers the entire door, as the cone of air from the fan should do (see recommendations in [16]). The research described in [17] has investigated optimal airflows when utilizing PPV against hot-fire conditions and suggested an ideal flow based upon a minimum value of 1000 m 3 Figure 6 shows Scenario 4A-flammable region after 20 and 60 s. The quantitative study detailed later shows that the apartment is almost empty of smoke gases, after around 60 s for low flow rate (Figure 16), and 40 s for high flow rate (Figure 15).…”

Section: Scenario 4: Offensive Attack Using Positive Pressure Ventilamentioning

confidence: 99%

“…To estimate the effect of different tactics on backdraft mitigation, the flammable region obtained in CFD simulations is plotted at different times in both defensive tactics, e.g. natural ventilation, or offensive tactics, such as using PPV fans [16][17][18] or dilution by water mist.…”

Section: Introductionmentioning

confidence: 99%

The Use of CFD Calculations to Evaluate Fire-Fighting Tactics in a Possible Backdraft Situation

Guigay

Gojkovic²,

Bengtsson

et al. 2008

Fire Technol

View full text Add to dashboard Cite

This paper is an attempt to integrate theoretical Computational Fluid Dynamics (CFD) calculations with practical fire-fighting tactics commonly used when arriving at the scene of an underventilated fire. The paper shows that CFD has a great potential in improving understanding and creating better effectiveness in the estimation of fire-fighting tactics. If burning has occurred in a lack of oxygen for a long time, excessive pyrolysis products may have accumulated in the fire compartment. If air is suddenly introduced in the compartment a backdraft may occur. The CFD code used for the simulations is fire dynamics simulator (FDS). In this paper, we focus on the conditions that can lead to backdraft, and not the deflagration or rapid combustion in itself. Therefore, the simulations focus on the gravity current and the mixing process between cold fresh air and hot smoke gases by considering a uniform temperature inside the building as initial condition. The different tactics studied include natural ventilation, positive pressure ventilation (PPV) and dilution by water mist. Their effectiveness is observed comparing them with a reference scenario, where no action is taken. The main objective of natural ventilation is to find the fire source, and the venting is more effective with several openings. Tactics involving PPV are very effective in evacuating the unburnt gases, but increases the mixing, and consequently the probability of backdraft during the early stage of operation. On the other hand, the addition of water mist can reduce the danger of backdraft by reducing the concentration of unreacted combustible gases below the critical fuel volume fraction (CFVF), where ignition cannot occur. If the dilution level is insufficient the danger of backdraft is increased, mainly because the process of gases evacuation is longer due to cooling, which reduces the density difference between hot and cold gases. During a fire-fighting operation, the choice of tactic depends mainly on whether there are people left in the building or not, but also on the fire-fightersÕ knowledge of the buildingÕs geometry and the fire conditions. If the situation shows signs of strongly underventilated conditions, the danger of backdraft has to be considered and the most appropriate mitigation tactics must be applied. 12 Nomenclature C airThe heat capacity of air (approximately 1 kJ/(kg K)) CFVF Critical fuel volume fraction CMC Critical mixture composition D(X) Dilution level, corresponds to a scenario with X % mass concentration GML Gas measurements line LFL Lower flammability limit M o Initial mass of hot gases M vap Mass of vapor added to obtain the desired dilution M CH4 Mass of unburnt gases (methane) Q fan Flow rate of the PPV fan tSimulation time T Temperature T final Temperature of hot gases after dilution T in Temperature of hot gases inside the compartment T out Temperature of cold gases outside the compartment (ambient) UFL Upper flammability limit v fan Velocity at the inflow boundary, due to PPV fan V gas Volume of hot gases in the en...

show abstract

“…Positive pressure ventilation is used to remove heat and smoke or prevent heat and smoke from entering the structure's stairwell and public hallways. Positive pressure ventilation is being applied by firefighters in smaller buildings to control fire-driven airflow by exerting pressure from the front door and venting the building via a strategic exit opening [80][81][82].…”

Section: Fire-wind Interaction Effects On Low-rise Buildingmentioning

confidence: 99%

Existing Improvements in Simulation of Fire–Wind Interaction and Its Effects on Structures

Ghodrat

Shakeriaski

Nelson

et al. 2021

Fire

View full text Add to dashboard Cite

This work provides a detailed overview of existing investigations into the fire–wind interaction phenomena. Specifically, it considers: the fanning effect of wind, wind direction and slope angle, and the impact of wind on fire modelling, and the relevant analysis (numerical and experimental) techniques are evaluated. Recently, the impact of fire on buildings has been widely analysed. Most studies paid attention to fire damage evaluation of structures as well as structure fire safety engineering, while the disturbance interactions that influence structures have been neglected in prior studies and must be analysed in greater detail. In this review article, evidence regarding the fire–wind interaction is discussed. The effect of a fire transitioning from a wildfire to a wildland–urban interface (WUI) is also investigated, with a focus on the impact of the resulting fire–wind phenomenon on high- and low-rise buildings.

show abstract

Evaluation of the ability of fire dynamic simulator to simulate positive pressure ventilation in the laboratory and practical scenarios

Cited by 9 publications

References 10 publications

Dependable Fire Detection System with Multifunctional Artificial Intelligence Framework

Dependable Fire Detection System with Multifunctional Artificial Intelligence Framework

The Use of CFD Calculations to Evaluate Fire-Fighting Tactics in a Possible Backdraft Situation

Existing Improvements in Simulation of Fire–Wind Interaction and Its Effects on Structures

Contact Info

Product

Resources

About