Numerical simulation of pressure changes in closed chamber fires

Chow, Wan Ki; Zou, G. W.

doi:10.1016/j.buildenv.2008.09.016

Cited by 47 publications

(19 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The self-extinction phenomena occurred at the time when the oxygen mole fraction in the flame reaches to a level of 10.7-15.3%. Chow and Zou [13,14] preformed several numerical simulation on closed chamber fires and suggested that the input heat release rate to fire dynamic simulator is a key point. Hu [15] conducted several fire experiments to investigate the compartment gas temperature distribution during smoke filling process.…”

Section: Introductionmentioning

confidence: 99%

An experimental study on crib fires in a closed compartment

2017

View full text Add to dashboard Cite

An experimental investigation on burning behavior of fire in closed compartments is presented. Fire experiments were performed in a closed compartment of interior dimensions 4 × 4 × 4 m (length × width × height) with ply board cribs as fire source. The parameters including the gas temperature, mass loss rate, heat flux, flame temperature, and compartment pressure were measured during the experiments. Experimental results indicated that the providing sudden ventilation to the closed compartment had great influence on the behavior of fire. The mass loss rate of the burning crib increased by 150% due to sudden ventilation which results in the increase in heat release rate by 198 kW. From the perspective of total heat flux, compartment pressure, and gas temperatures closed compartment with sudden ventilation were more hazardous.

show abstract

Section: Introductionmentioning

confidence: 99%

An experimental study on crib fires in a closed compartment

2017

View full text Add to dashboard Cite

show abstract

“…CFD predictions with FDS on the current airflow problem related to turbulent exchange flow across the opening has been justified (Chow and Zou, 2005). Grid size analysis of earlier versions of the CFD-FDS package to resolve the flow in the a turbulent fire plume was reported by Ma and Quintiere (2003), and comparisons of different versions in a close chamber fire by Chow and Zou (2009). However, in depth studies on how the location of the external (i.e.…”

Section: Deriving An Empirical Equation From the Cfd Analysismentioning

confidence: 98%

Possible Air Pumping Action in a Room Fire

Chow¹,

Zuo

Chow

2012

International Journal of Ventilation

Self Cite

View full text Add to dashboard Cite

The air pumping effect of a fire plume, proposed years ago, to give a higher air intake rate through vertical openings in a compartment fire is further investigated in this paper. Equations for the air intake rate through vertical openings found in the literature are reviewed. As most of the reported correlation expressions were derived empirically from experiments, results might be different if the fire geometry, fuel type and ambient conditions are different. Furthermore, most of the data on heat release rates in earlier experiments were measured from the mass loss rate of fuel, not by the oxygen consumption method. Values used therefore might deviate from the actual heat release rates. Aerodynamic flow through a doorway, induced by a compartment fire, is commonly simulated by Computational Fluid Dynamics (CFD). Factors which are difficult to control in experiments but affecting the doorway airflow can be studied more easily with CFD.In the study presented in this paper a two-room structure with a fire room connected to an adjacent room through a door was selected. Different door widths linking the two rooms were set to give different ventilation factors. A total number of 16 simulations using the popular CFD software, Fire Dynamics Simulator, based on large eddy simulations, were carried out with different heat release rates of a fire in the fire room. Predicted horizontal velocity components were used to estimate the air intake rates through the door to justify the air pumping action. It appears that there is an air pumping effect of the fire plume for cases with lower ventilation factors, even for pre-flashover fires. Results further confirmed earlier experimental data on post-flashover fires. Therefore, further study on possible air pump effects in a room fire is strongly recommended.

show abstract

“…There is no sensitivity study on smoke movement in tall buildings as the present problems. Some results reported earlier on closed pressure chamber and atrium hot smoke tests (Chow and Zou 2009;) indicated that grid size similar to this study would be adequate to understand the probable fire-induced flow pattern and air temperature contours.…”

Section: Wind-induced Air Flowmentioning

confidence: 98%

Fire Safety Aspects of Refuge Floors in Supertall Buildings With Computational Fluid Dynamics

Chow

2009

Journal of Civil Engineering and Management

View full text Add to dashboard Cite

Abstract. High-rise buildings in many big cities in the Far East, including Hong Kong, call for refuge floors as a matter of both practicality and compliance with regulations. Even though many countries' fire codes are not clear in spelling out the necessity for refuge floors, it is accepted within construction that such floors are essential in resisting fire, allowing users a means of escape and allowing emergency services a means of access to stricken buildings. This paper discusses the reasons behind providing refuge floors, while also considering related fire safety provisions, such as their enclosure behind fire-resistant construction or the protection of their openings behind a water curtain. Our discussion takes a tall building with balconies as a test example of refuge floors, running a hazard assessment based on Computational Fluid Dynamics assuming a fire of the broadly accepted level of 2 MW. The paper concludes that the design of the building's façade finally determines whether or not a refuge floor and associated fire safety provisions, such as a water curtain, can be waived. As the flat modelled used to store a high amount of combustibles up to 1135 MJm -2 , the breaking of large area of glass window could lead to a major conflagration. The consequences of a scenario with a fire of 25 MW are also discussed.

show abstract

Numerical simulation of pressure changes in closed chamber fires

Cited by 47 publications

References 8 publications

An experimental study on crib fires in a closed compartment

An experimental study on crib fires in a closed compartment

Possible Air Pumping Action in a Room Fire

Fire Safety Aspects of Refuge Floors in Supertall Buildings With Computational Fluid Dynamics

Contact Info

Product

Resources

About