Fire Dynamics Simulator (Version 4.0) Simulation for Tunnel Fire Scenarios with Forced, Transient, Longitudinal Ventilation Flows

2007 ◽  
Vol 44 (2) ◽  
pp. 137-166 ◽  
Author(s):  
Esther Kim ◽  
John P. Woycheese ◽  
Nicholas A. Dembsey
Keyword(s):  
Fire Dynamics ◽  
Fire Dynamics Simulator ◽  
Tunnel Fire ◽  
Longitudinal Ventilation ◽  
Fire Scenarios

Numerical Analysis of Evacuation from Taiwan Hsuehshan Tunnel Fire

2014 ◽  
Vol 955-959 ◽  
pp. 1840-1849
Author(s):  
Cherng Shing Lin ◽  
Kuo Da Chou
Keyword(s):  
Numerical Simulation ◽  
Fire Protection ◽  
Quantitative Data ◽  
Relevant Information ◽  
Simulation Software ◽  
Escape Time ◽  
Fire Dynamics ◽  
Fire Dynamics Simulator ◽  
Tunnel Fire ◽  
Protection Engineering

Taiwan is an island nation with numerous mountains and few plains. Consequently, the number of tunnel projects has gradually increased and tunnels are becoming longer. Because the number of large tunnels that exceed 1000 meters in length has increased, the effective escape and evacuation of people during a fire and the minimization of injury are crucial to fire protection engineers. For this study, an actual example of a fire that occurred in Hsuehshan Tunnel (12.9 kilometers and the longest tunnel in Southeast Asia) was used. A fire dynamics simulator (FDS) including numerical simulation software was applied to analyze this fire and the relevant information that was collected was compared and verified. The fire site simulation showed the escape and evacuation of people during the fire. Simulations of the original fire site and the possible escape time for people with various attributes were discussed to provide quantitative data and recommendations based on the analysis results, which can serve as a reference for fire protection engineering.

scholarly journals Tunnel Fire Dynamics as a Function of Longitudinal Ventilation Air Oxygen Content

2019 ◽  
Vol 11 (1) ◽  
pp. 203 ◽  
Author(s):  
Sanjay Kumar Khattri ◽  
Torgrim Log ◽  
Arjen Kraaijeveld
Keyword(s):  
Oxygen Content ◽  
Oxygen Concentration ◽  
Ambient Air ◽  
Fire Dynamics ◽  
Maximum Heat ◽  
Tunnel Fire ◽  
Longitudinal Ventilation ◽  
Rate Maximum ◽  
Air Ventilation ◽  
Safety Parameters

Longitudinal ambient air ventilation is the most common methodology for maintaining an amicable environment in tunnels during normal operations while providing an evacuation path during tunnel fire emergencies. The present work investigates the influence of forced ventilation air oxygen concentrations on tunnel fire dynamics. Mixing inert gasses such as nitrogen, argon, or carbon dioxide with ambient air changes the ventilation air oxygen concentration. In order to quantify the influence of the oxygen content on the critical tunnel safety parameters, multiple computational fluid dynamics (CFD) simulations were done on a reduced-size tunnel while preserving the system Froude number. Analytical expressions were developed to describe the importance of oxygen content on the tunnel fire dynamics. By employing Froude scaling, the resulting relations were extrapolated to real scale tunnels. For the ambient air ventilation, the extrapolated expressions displayed good agreement with experimental literature data. By adjusting the oxygen concentration, parameters such as maximum tunnel ceiling temperature, fire growth rate, maximum heat flux to the tunnel floor, maximum flux on the tunnel ceiling, and maximum heat release rate can be controlled. This is the case also for oxygen levels where people can survive. This may increase the possibility for evacuation and improve the conditions for firefighting, significantly improving tunnel fire safety.

A Study on Tunnel Smoke Control Strategies by Experiment and Numerical Simulation

2011 ◽  
Vol 402 ◽  
pp. 864-867
Author(s):  
Xiao Yang Liu ◽  
Jing Yan Zhang ◽  
Yan Feng Li ◽  
Li Li Zhang ◽  
Jin Feng Yuan
Keyword(s):  
Scale Model ◽  
Road Tunnel ◽  
Smoke Control ◽  
Fire Control ◽  
Fire Dynamics ◽  
Tunnel Fire ◽  
Longitudinal Ventilation ◽  
Fire Smoke ◽  
Smoke Layer ◽  
Layer Velocity

In order to meet the need of the study on the tunnel fire safety system, taking the tunnel laboratory bench in the key laboratory of the university of science and technology of China as the object, this paper does a scale model experiment on the tunnel fire, and uses the Fire Dynamics Simulator（FDS）software to simulate fire smoke layer velocity under different longitudinal ventilation control, by comparing the experimental and simulation results, this paper not only gives the variation law of the tunnel fire smoke layer velocity under different longitudinal ventilation speed, but also proposes the concept of the smoke stratification critical wind speed , which will provide some references for the road tunnel fire control, rescue and evacuation.

Using experimental sprinkler actuation times to assess the performance of Fire Dynamics Simulator

2018 ◽  
Vol 36 (4) ◽  
pp. 342-361 ◽  
Author(s):  
Charlie Hopkin ◽  
Michael Spearpoint ◽  
Adam Bittern
Keyword(s):  
Degrees Of Freedom ◽  
Goodness Of Fit ◽  
Relative Difference ◽  
Sensitivity Analyses ◽  
Fire Dynamics ◽  
Actuation Time ◽  
Fire Dynamics Simulator ◽  
Fire Scenarios ◽  
Modelling Studies ◽  
Modelling Methods

This article considers the predictive capabilities of Fire Dynamics Simulator for sprinkler actuation time when benchmarked against data from a series of 22 enclosure experiments. Sensitivity analyses have been undertaken for grid size, conductivity factor, radiative fraction and enclosure leakage areas. ‘Goodness of fit’ calculations indicate that Fire Dynamics Simulator is able to provide an average prediction of sprinkler actuation time within a Euclidean relative difference of 0.18. Comparisons to results determined in previous studies, using different modelling methods and Fire Dynamics Simulator versions, have also been made. The sensitivity analyses and comparisons indicate the importance of the decisions made by the modeller in representing fire scenarios, even when modelling ‘simple’ experiments where data for inputs such as the heat release rate, geometry and sprinkler characteristics are available. The comparisons therefore indicate that with the reduced degrees of freedom compared to other modelling studies, there is still potential for a range of assumptions and simulation results.

scholarly journals Numerical study on the effect of shaft position on natural smoke exhaust in tunnels with one closed portal

2020 ◽  
Vol 194 ◽  
pp. 05061
Author(s):  
GENG Pengqiang ◽  
WANG Zihao ◽  
WENG Miaocheng ◽  
LIU Fang
Keyword(s):  
Temperature Distribution ◽  
Heat Release ◽  
Release Rate ◽  
Numerical Study ◽  
Fire Dynamics ◽  
Fire Dynamics Simulator ◽  
Fire Source ◽  
Tunnel Fire ◽  
Ceiling Temperature ◽  
Longitudinal Distance

.This paper uses Fire Dynamics Simulator (FDS) to study the effect of the longitudinal distance from the shaft to the fire source on the natural smoke exhaust of the tunnel fire with one closed portal, and analyzes the temperature distribution of the smoke and the shaft’s smoke exhaust efficiency. The results show that when the shaft is located downstream of the fire source (Ds<0), with the increase of the distance from the shaft to the fire source, the smoke exhaust efficiency decreases first and then stabilizes at a fixed value. At this time, the ceiling temperature attenuation’s coefficient at upstream of the fire source is only related to the heat release rate of the fire source (HRR). When the shaft is located upstream of the fire source (Ds>0), the smoke exhaust efficiency increases slightly with the increase of the distance from the shaft to the fire source, but the overall value is relatively small. When HRR is fixed, the shaft located downstream of the fire source has a higher smoke exhaust efficiency. As the distance between the shaft and the fire source increases, the plug phenomenon decreases.

Evaluation of Positive Pressure Ventilation for High-Rise Buildings in Compartment Fire Situation

2012 ◽  
Vol 446-449 ◽  
pp. 2908-2913 ◽  
Author(s):  
Xiao Feng ◽  
Yan Feng Li
Keyword(s):  
Positive Pressure Ventilation ◽  
Optimal Rate ◽  
Positive Pressure ◽  
Airflow Rate ◽  
Compartment Fire ◽  
Fire Dynamics ◽  
High Rise ◽  
Fire Dynamics Simulator ◽  
Fire Condition ◽  
Fire Scenarios

An alternate means for protecting high-rise stairwell enclosures using the positive pressure ventilation is evaluated. An analysis performed by using the Fire Dynamics Simulator (FDS) model shows that the positive pressure ventilation can be an effective method for protecting the stairwell enclosure. Three types of ventilation methods are compared in the same fire condition and the best one is determined based on the decrease of temperature in the stairwell. The optimal rate for ventilating the stair requires optimization of the airflow rate according to postulated fire scenarios for the building and the desired performance with respect to tenability conditions within the stair.

scholarly journals FDS simulation of smoke backlayering in emergency lay-by of a road tunnel with longitudinal ventilation

2021 ◽  
Vol 2090 (1) ◽  
pp. 012100
Author(s):  
P Weisenpacher ◽  
J Glasa ◽  
L Valasek ◽  
T Kubisova
Keyword(s):  
High Performance ◽  
Road Tunnel ◽  
Smoke Movement ◽  
Fire Dynamics ◽  
Computer Cluster ◽  
Longitudinal Ventilation ◽  
Smoke Spread ◽  
Fire Scenarios ◽  
Significant Length ◽  
High Performance Computer

Abstract This paper investigates smoke movement and its stratification in a lay-by of a 900 m long road tunnel by computer simulation using Fire Dynamics Simulator. The lay-by is located upstream of the fire in its vicinity. The influence of lay-by geometry on smoke spread is evaluated by comparison with a fictional tunnel without lay-by. Several fire scenarios with various tunnel slopes and heat release rates of fire in the tunnels without and with the lay-by are considered. The most significant breaking of smoke stratification and decrease of visibility in the area of the lay-by can be observed in the case of zero slope tunnel for more intensive fires with significant length of backlayering. Several other features of smoke spread in the lay-by are analysed as well. The parallel calculations were performed on a high-performance computer cluster.

Sign in / Sign up

Export Citation Format

Share Document