scholarly journals Analysis of smoke stratification and smoke layer thickness in underground car parks

2018 ◽  
Vol 22 (5) ◽  
pp. 1963-1972
Author(s):  
Zeljko Spiljar ◽  
Daniel Schneider ◽  
Miodrag Drakulic
Keyword(s):  
Numerical Modelling ◽  
Layer Thickness ◽  
Time Interval ◽  
Building Structure ◽  
Smoke Movement ◽  
Evacuation Time ◽  
Smoke Layer ◽  
Car Park ◽  
Fire Accidents ◽  
Fire Design

Fire accidents in underground car parks have a significant impact on the building structure and lives of people and firefighters. Different methods are used to obtain a reliable estimation of fire and hot smoke influence on the building structure. Numerical modelling is crucial in the fire design and is a useful tool to determine smoke stratification and clear layers for safe human evacuation and firefighter access. Smoke stratification can be checked separately for any time interval in any section of an underground car park, regardless of the underground car park architecture complexity. This paper describes numerical modelling of smoke stratification and movement in an underground car park. The results show smoke movement and smoke layer thickness during the evacuation time, and how they can help reduce the harmful influence of fire on the underground car park structure.

On the Smoke Propagation of a Fire in a Tunnel With Concentrated Exhaust Ventilation

2011 ◽  
Author(s):  
Futoshi Tanaka ◽  
Masahiro Kato ◽  
Shouhei Majima ◽  
Nobuyoshi Kawabata ◽  
Tomoki Kikumoto ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Scaling Law ◽  
Experimental Results ◽  
Exhaust Ventilation ◽  
Tunnel Fire ◽  
The People ◽  
Fire Smoke ◽  
Smoke Layer ◽  
Fire Accidents ◽  
Real Scale

In recent years, tunnel fire accidents of about 20 occur every year in Japan. The Nihonzaka and the Sakai tunnel fire accidents are as famous typical examples. When concentrated exhaust ventilation device is activated in such a tunnel fire, it is of concern that the people who take shelter receive damage from the fire smoke. When a tunnel fire occurs, the concentrated exhaust ventilation device is stopped in Japan. Therefore, the research on the use of concentrated exhaust ventilation device at a tunnel fire has not advanced in Japan. The purpose of this study is to clarify the smoke propagation when concentrated exhaust ventilation device is activated. The model tunnel in the scale of 1/5 was used in this study. Froude scaling law was used to make the experimental results of the model tunnel correspond to the real scale tunnel. The concentrated exhaust ventilation device installed on the model tunnel extracts the fire smoke from a chimney. The smoke distribution in the model tunnel was measured with smoke concentration meters. In the case that the exhaust ventilation device was activated, the smoke layer thickness of the downstream of the chimney thinned. However, in the upstream of the chimney, the smoke layer thickness did not change though the exhaust ventilation device was activated.

Multi-Cell Concept for Simulating Fires in Big Enclosures Using a Zone Model

1996 ◽  
Vol 14 (3) ◽  
pp. 186-198 ◽  
Author(s):  
W.K. Chow
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Temperature Distribution ◽  
Physical Properties ◽  
Flow Pattern ◽  
Layer Thickness ◽  
Zone Model ◽  
Smoke Layer

The multi-cell concept is applied to simulate fire in a big com partment with the zone model CFAST. The predicted physical properties of the smoke layer are used to justify the results, including the smoke layer tempera ture, smoke layer thickness and flows between each cell. Microscopic pictures of the flow pattern and smoke temperature distribution similar to the results pre dicted by the Computational Fluid Dynamics technique can be obtained. This idea is recommended to study fires in big enclosures.

scholarly journals Full-scale and reduced-scale tests on smoke movement in case of car park fire

2013 ◽  
Vol 57 ◽  
pp. 35-43 ◽  
Author(s):  
István Horváth ◽  
Jeroen van Beeck ◽  
Bart Merci
Keyword(s):  
Full Scale ◽  
Smoke Movement ◽  
Car Park ◽  
Reduced Scale

Study of Smoke Stratification in Atrium Halls Using Scale Model

2009 ◽  
Author(s):  
N. K. Fong ◽  
C. H. Ko
Keyword(s):  
Air Temperature ◽  
Detection System ◽  
National Fire Protection Association ◽  
Ambient Air ◽  
Scale Model ◽  
Triangular Prism ◽  
Smoke Movement ◽  
Smoke Plume ◽  
Smoke Layer ◽  
Plume Temperature

Nowadays, atrium building is very popular because it can provide extensity and attraction to the users even if they are inside the enclosed environment. Similar to other buildings, fire safety is one of the major concerns especially the atrium are linked to shopping arcades. The major challenge is to control the smoke movement in the case of fire and maintain a stable smoke layer clear height to allow sufficient time for the occupants to evacuate from the building. Therefore, an efficient smoke management system (SMS) is necessary. For the SMS to function properly, the smoke behaviour inside the atrium must be studied. One of the phenomena affecting the operation of the SMS is smoke stratification. That is, due to the vertical temperature gradient inside the atrium, a thermally stratified environment is formed and smoke will not be able to reach the smoke detectors/smoke outlets in the ceiling. In the past decade, various studies were conducted to study the smoke filling process in the atrium. Only a few studies were carried out to study smoke stratification in atrium. This paper attempted to study the factors leading to the development of thermally stratified environment in an atrium and the formation of smoke stratification under the ceiling space of an atrium building using scale model. These factors included the temperature of the smoke plume, the air temperature under the ceiling, the configuration of roof ceiling and the ambient air temperature. Two types of ceiling configurations such as a cuboid and a triangular prism are used. Data concerning the ceiling air temperature, smoke plume temperature, effect of different ceiling configuration and maximum smoke layer height in a thermally stratified environment are collected. Comparisons are conducted with the calculated results from National Fire Protection Association (NFPA) 92B equations. With all these information, better design criteria of smoke detection system, SMS in an atrium building can be developed. Finally, the experimental results can be used to investigate the discrepancies between the experimental measurement and the calculated results from NFPA 92B equations. Put abstract text here.

scholarly journals MODELLING OF FIRE IN AN OPEN CAR PARK

2016 ◽  
Author(s):  
Timea Márton ◽  
Anne Dederichs ◽  
Luisa Giuliani
Keyword(s):  
Mechanical Properties ◽  
High Temperatures ◽  
Fire Spread ◽  
Current Paper ◽  
Spread Rate ◽  
Dynamic Simulator ◽  
Car Park ◽  
Fire Dynamic Simulator ◽  
Fire Accidents

Steel car parks exhibit high vulnerability to fire, as a consequence of the degradation of the steel mechanical properties at high temperatures and of the combustible type and amount. Real fire accidents in open car parks demonstrated a much faster and extended fire spread than predictions, assuming that a fire spread rate of 12 min and consider at most 3-4 vehicles on fire at the same time. Fire Dynamic Simulator (FDS) is applied in this current paper to study fire spread between cars. The outcomes of the investigations show that the fire spread is strongly influenced by the geometrical layout and that the distance between cars plays a determinant role on the fire spread rate and ignition of adjacent cars. In particular it was found that the fire spread can be faster than 12 minutes in the case of the cars parked 40 and 60 cm from each other.

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