Numerical Simulations on Airflow to the Double-Skin Fac¸ade Cavity by an Adjacent Room Fire

Author(s):  
C. L. Chow

The architectural feature of double-skin fac¸ades has been proposed in green or sustainable buildings. However, there are potential fire risks and so the design was normally not accepted by the authorities having jurisdictions. The scenario of trapping heat and smoke in the fac¸ade cavity is identified as hazardous and should be better understood. Hot smoke flowing out of openings driven by an adjacent room fire to the double-skin fac¸ade cavity was simulated using computational fluid dynamics (CFD). A five-level building model was taken as an example. A fire occurred in a room at the third level under two different heat release rates of 1 MW and 5 MW, and cavity depths of 0.5 m, 1 m and 2 m were considered. Based on the simulation results, three stages of flame spreading from the room fire to the adjacent fac¸ade cavity were proposed in fire hazard assessment for this architectural feature. Results suggested that wider cavity depths would be more dangerous, having a greater chance to break the adjacent upper interior glass panes. Smoke or even flames can then spread to the upper levels.

2011 ◽  
Vol 17 (3) ◽  
pp. 371-392 ◽  
Author(s):  
Cheuk Lun Chow

Double-skin façade (DSF) is an environmental friendly architectural feature. However, fire hazard is a concern. A scenario of having a flashover room fire adjacent to the façade was identified. Heat and mass would be trapped in the façade cavity. This paper examines air flow driven out of a flashover room fire to the cavity of a DSF by Computational Fluid Dynamics. The software Fire Dynamics Simulator developed at the Building and Fire Research laboratory, National Institute of Standards and Technology, USA was selected as the simulation tool. Three DSF features labeled as DSF1, DSF2 and DSF3 were considered. Detailed simulations were carried out to understand the fire-induced aerodynamics in a 5-level model DSF1 with a fire room at the third level. Hot gas spreading out to the façade cavity was simulated under two heat release rates of 1 MW and 5 MW. Air cavity depths of 0.5 m, 1 m, 1.5 m and 2 m were considered. Three stages of flame spreading out to a DSF with a wide air cavity depth were identified. Results suggested that wider air cavity depths would be more dangerous, with higher risk of the upper interior glass pane's breaking. To study spreading of heat and mass up the façade cavity as vertical channel flow, two taller DSF façade features DSF2 and DSF3 with differing air cavity depths were simulated. Both features were of height 24 m but of differing fire room height. Vertical temperature profiles with and without the DSF feature were compared. Santrauka Dvigubas fasadas yra ekologiškas architektūrinis sprendimas. Tačiau dvigubas fasadas yra problemiškas gaisrinės saugos požiūriu. Nagrinėjamas scenarijus, kai greta dvigubo fasado esančioje patalpoje įvyksta gaisro pliūpsnis. Dvigubo fasado ertmėje gali būti uždaryti karštis ir masė. Taikomi skaitmeninės skysčių dinamikos metodai nustatyti, kaip iš patalpos, kurįoje įvyksta gaisro pliūpsnis, oras ir degimo produktai išstumiami ī dvigubo fasado ertmę. Modeliuoti naudojama kompiuterinė programa, parengta JAV Nacionaliniame standartų ir technologijos institute. Nagrinėjami trys dvigubų fasadų sprendimai. Atliekamas detalus pirmojo sprendimo fasado modeliavimas siekiant suprasti gaisro lemiamą aerodinamiką penkių aukštų fasade, kai gaisras kyla trečiame aukšte. Modeliuojamas karštu dujų sklidimas iš fasado ertmės viršaus teigiant, kad gaisro išskiriama Siluma yra 1 MW ir 5 MW. Ertmės plotis imamas lygiu 0,5 m, 1,5 m ir 2 m. Nustatomi trys liepsnos sklidimo iš dvigubo fasado etapai. Gauti rezultatai leidžia daryti išvadą, kad platesni fasadai yra pavojingesni, nes didina viršutinių stiklo diskų dužimo tikimybę. Aukštesni antro ir trečio sprendimo fasadai naudoti tirti, kaip karštis ir masė juda vertikalia fasado ertme. Skyrėsi šių fasadų ertmės plotis. Abu fasadai buvo 24 m aukščio, tačiau skyrėsi gaisro patalpos aukštis. Buvo palygintas vertikalusis temperatūros pasiskirstymas dvigubo fasado ertmėje.


2012 ◽  
Vol 468-471 ◽  
pp. 1753-1757
Author(s):  
Yang Wei Shao ◽  
Shih Feng Kao ◽  
Neng Chun Yu ◽  
Yu Shiang Wu ◽  
Chi Jan Huang ◽  
...  

Although meeting the regulations of the time, early buildings are prone to fire hazards, such as damages to the fire zones, changes of floor entrances and exits, locked emergency exit doors, blocking of entrances and exits by vehicles, increased fire sources, dense population in the buildings, due to insufficient professional knowledge and technology in fire prevention. Once a fire occurs, it can result in major casualties, serious loss of social costs, as well as environmental and social issues. This study investigated 17 major fire cases occurring in residential-commercial composite buildings in the last 20 years in Taiwan. The fire hazard factors were determined based on expert review. The findings can serve as a reference for fire agencies in promoting fire prevention.


2014 ◽  
Vol 694 ◽  
pp. 256-259
Author(s):  
Xin Zhan ◽  
Hua Yang ◽  
Feng Yun Jin

Airflow and heat transfer simulation was conducted for a double-skin façade (DSF) system equipped with shading devices in the cavity, using computational fluid dynamics (CFD) with RNG turbulence model and PISO algorithm, for five conditions of slat angles (θ=0°, 30°, 45°, 60°, 90°). The present study indicates that the presence of shading devices influences the temperatures, the ventilation rate and the air distribution in the DSF system. Besides, the different angles will make different influences.


JOURNAL ASRO ◽  
2021 ◽  
Vol 12 (02) ◽  
pp. 10
Author(s):  
Dodiek Alfianzi ◽  
Ikhwan Syahtaria ◽  
Udisubakti Cipto Mulyono ◽  
I Made Jiwa Astika

Designing a fire prevention inspection system in buildings is very necessary, to determine the level of reliability. The fire prevention management system uses the following criteria: precautionary measures and preventive supervision against fire hazards. The assessment of the system design is carried out by means of a questionnaire for respondents who understand / are experts in fire problems, and the application of the system design uses direct surveys and questionnaires to the building manager. The assessment is carried out at the smallest level. Analysis of the building reliability inspection system in fire prevention using the Analytical Hierarchy Process (AHP) method, the criteria used are: prevention, limitation and extinguishing against fire. The fire prevention management system uses the following criteria: precautionary measures and preventive supervision against fire hazards. The results of the reliability inspection of the Ki Hadjar Dewantara Mako Kodiklatal building in Surabaya with a value of 94.06% indicated that the reliability system was in the "Less Reliable" category for fire hazard prevention.   Keywords: Inspection, fire prevention, reliability.


2021 ◽  
Author(s):  
Verónica Dankiewicz ◽  
Matilde M. Rusticucci ◽  
Soledad M. Collazo

<p>Forest fires are a global phenomenon and result from complex interactions between weather and climate conditions, ignition sources, and humans. Understanding these relationships will contribute to the development of management strategies for their mitigation and adaptation. In the context of climate change, fire hazard conditions are expected to increase in many regions of the world due to projected changes in climate, which include an increase in temperatures and the occurrence of more intense droughts. In Argentina, northwestern Patagonia is an area very sensitive to these changes because of its climate, vegetation, the urbanizations highly exposed to fires, and the proximity of two of the largest and oldest National Parks in the country. The main objective of this work is to analyze the possible influence of climate change on some atmospheric patterns related to fire danger in northwestern Argentine Patagonia. The data were obtained from two CMIP5 global climate models CSIRO-Mk3-6-0 and GFDL-ESM2G and the CMIP5 multimodel ensemble, in the historical experiment and two representative concentration pathways: RCP2.6 and RCP8.5. The data used in this study cover the region's fire season (FS), from September to April, and were divided into five periods of 20 years each, a historical period (1986-2005), which was compared with four future periods: near (2021-2040), medium (2041-2060), far (2061-2080) and very far (2081-2100). The statistical distribution of the monthly composite fields of the FS was studied for some of the main fire drivers: sea surface temperature in the region of the index EN3.4 (SST EN3.4), sea level pressure anomalies ​​(SLP), surface air temperature anomalies (TAS), the Antarctic Oscillation Index (AOI) and monthly accumulated precipitation (PR). In addition, the partial correlation coefficient was calculated to determine the independent contribution of each atmospheric variable to the Fire Weather Index (FWI), used as a proxy for the mean FS danger. As a result, we observed that SST EN3.4 is the only one that could indicate a reduction in fire danger in the future, although no variable presented a significant contribution to the FWI with respect to the others. In the RCP8.5 scenario, greater fire danger is projected by the TAS, the PR, the SLP, and relative by the AOI, while in the RCP2.6 scenario, only the TAS shows influence leading to an increase, which would be offset by the opposite influence of SST EN3.4 for the same periods in this scenario. In conclusion, in RCP8.5 it could be assumed that there is a trend towards an increase in fire danger given the influence in this sense of most of the variables analyzed, but not in RCP2.6 where there would be no significant changes.</p>


Author(s):  
Kedar Pathak ◽  
Kendrick Aung

Study of fire in a tunnel is very important for fire safety. Increasing concerns over terrorism put a lot of focus on the fires in tunnels as they are used extensively in mass transit systems all over the world. A lot of experiments have been carried out to study the fire hazard, smoke movement, and the effects of ventilation on fire behavior. In this paper, dynamics of a ventilated tunnel fire have been simulated using Computational Fluid Dynamics (CFD) Software, CFX 5.6, from Ansys Inc. Simulations considers different models of turbulence and radiation heat transfer. Combustion of methane is modeled using the chemical reaction schemes available in the CFX software. Two turbulent models, k–ε and Shear Stress Transport, are considered. Radiant heat exchange between the species is modeled using P1 model available in CFX 5.6. The results of the simulation have highlighted the effects of ventilation on the fire and movement of harmful gases such as carbon monoxide and nitrogen oxide. Comparison of simulated temperature fields and flame shape with the experimental data has shown good agreement.


2011 ◽  
Vol 368-373 ◽  
pp. 1175-1181
Author(s):  
Shu Ping Zhang ◽  
Wen Jun Wei

This paper took a large store building from Xi'an city which was on fire in 2008 to be the research object, simulating fire smoke, temperature and flame situation with FDS computer numerical simulation, and performed a comparative analysis with its real fire scene pictures. The research shows that during the early 12 minutes, the flamed area is small, the simulated temperature, smoke are highly coherent with the real scene; In the mean time, when considering the whole spreading tendency of building fire in a period of time from macro angle, large eddy simulation can truly reflect fire transient turbulence properties, but the volumetric heat source method has some limitations in fire spreading simulation, thereby it will have a certain affect on smoke flowing simulation.


2018 ◽  
Vol 32 ◽  
pp. 01020 ◽  
Author(s):  
Sebastian Valeriu Hudişteanu ◽  
Cătălin George Popovici ◽  
Nelu-Cristian Cherecheş

The paper presents a wind tunnel experimental analysis of a small-scale building model (1:30). The objective of the study is to determine the wind influence on the ventilation of a double skin façade channel (DSF) and the cooling effect over integrated photovoltaic panels. The tests were achieved by conceiving and implementation of an experimental program using a wind tunnel with atmospheric boundary layer. The effect of the wind over the ventilation of the horizontal channels of double skin façades is evaluated for different incident velocities. The results are generalized for the average steady state values of the velocities analysed. The experimental results put in evidence the correlation between the reference wind velocity and the dynamics of the air movement inside the double skin façade. These values are used to determine the convective heat transfer and the cooling effect of the air streams inside the channel upon the integrated photovoltaic panels. The decrease of the photovoltaic panels temperature determines a raise of 11% in efficiency and power generated.


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