scholarly journals Computational modeling of fire safety in metro-stations

2021 ◽  
Author(s):  
Philip McKeen
Keyword(s):  
Fire Safety ◽  
Performance Based Design ◽  
Cfd Model ◽  
Fire Dynamics ◽  
Evacuation Modeling ◽  
Fire Dynamics Simulator ◽  
Cfd Models ◽  
Smoke Spread ◽  
Modeling Software ◽  
Computational Fluid Dynamics Cfd

This research investigates and attempts to quantify the hazards associated with fire in metrostations. The use of numerical simulations for the analysis of fire safety within metro-stations allows for the prediction and analysis of hazards within the built environment. Such approaches form the growing basis of performance based design (PBD), which can optimize design solutions. The simulations utilize Fire Dynamics Simulator (FDS), a Computational Fluid Dynamics (CFD) model and Pathfinder, an evacuation modeling software. The safety of underground metro-stations is analyzed through the simulation of smoke spread and egress modelling. CFD models of TTC’s Union Station and TransLink’s Yaletown Station are developed to allow for simulations of smoke spread scenarios. These models are evaluated in regards to the preservation of tenability and influence on the Available Safe Egress Time (ASET). The egress of metro-stations is modelled and analyzed to determine the Required Safe Egress Time (RSET).

scholarly journals Computational modeling of fire safety in metro-stations

2021 ◽  
Author(s):  
Philip McKeen
Keyword(s):  
Fire Safety ◽  
Performance Based Design ◽  
Cfd Model ◽  
Fire Dynamics ◽  
Evacuation Modeling ◽  
Fire Dynamics Simulator ◽  
Cfd Models ◽  
Smoke Spread ◽  
Modeling Software ◽  
Computational Fluid Dynamics Cfd

This research investigates and attempts to quantify the hazards associated with fire in metrostations. The use of numerical simulations for the analysis of fire safety within metro-stations allows for the prediction and analysis of hazards within the built environment. Such approaches form the growing basis of performance based design (PBD), which can optimize design solutions. The simulations utilize Fire Dynamics Simulator (FDS), a Computational Fluid Dynamics (CFD) model and Pathfinder, an evacuation modeling software. The safety of underground metro-stations is analyzed through the simulation of smoke spread and egress modelling. CFD models of TTC’s Union Station and TransLink’s Yaletown Station are developed to allow for simulations of smoke spread scenarios. These models are evaluated in regards to the preservation of tenability and influence on the Available Safe Egress Time (ASET). The egress of metro-stations is modelled and analyzed to determine the Required Safe Egress Time (RSET).

Points to Note in Modeling Fire With Computational Fluid Dynamics

2012 ◽  
Author(s):  
L. Qu ◽  
W. K. Chow
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Design Tool ◽  
Performance Based Design ◽  
Cfd Model ◽  
Fire Dynamics ◽  
Design Fire ◽  
Computational Fluid Dynamics Cfd ◽  
Three Dimensional Simulations

Computational Fluid Dynamics (CFD) is a popular design tool in many projects for ensuring fire safety through performance-based design. However, there are always challenges on the quality and uncertainties of the CFD simulated results. Two points raised are on the grid size and free boundary conditions. A simple corridor fire with a small design fire is taken as an example to address these two points in this paper. The CFD model Fire Dynamics Simulator (FDS) version 5 was taken as the simulation tool Two-dimensional and three-dimensional simulations are compared. The geometry is proposed to outside for better description on minimizing opening boundary.

CFD Simulation of Smoke Spread Through Elevator Shafts During Fires in High Rise Buildings

2015 ◽  
Author(s):  
Qize He ◽  
Ofodike A. Ezekoye ◽  
Beth Tubbs ◽  
Carl Baldassarra
Keyword(s):  
Cfd Simulation ◽  
Gas Temperature ◽  
Fire Dynamics ◽  
High Rise ◽  
Fire Dynamics Simulator ◽  
Smoke Spread ◽  
Outflow Rate ◽  
Computational Fluid Dynamics Cfd ◽  
Temperature And Pressure ◽  
Two Phases

Smoke spread through the elevator shafts of high rise buildings has been numerically investigated using the Fire Dynamics Simulator (FDS), which is a computational fluid dynamics (CFD) program suitable for fire induced heat and mass transfer. A model of a high rise building was developed and a fire was set at the first level. The smoke spread process through the elevator shafts was evaluated. The process can be divided into two phases. In the first phase, the smoke gradually fills the shafts, and the gas temperature and pressure in the shafts are transient. After this phase, the smoke fully fills the shafts, the temperature and pressure in the shaft are almost steady, which suggests that the smoke inflow rate equals the outflow rate. Throughout the process, the spatial distributions of temperature and pressure in the elevator shaft under fire situations were reported. The hot fire product gases entering the shaft causes a stack effect, which transports smoke to the upper levels. A method of partially enclosing the elevator lobbies was also investigated by the CFD simulation. The results were compared with the unenclosed situation, and showed that enclosing lobbies not only increases the time needed for the smoke to fully fill the shafts, but also reduces the temperature and pressure differences in the shafts.

scholarly journals A Study on Microscale Wind Simulations with a Coupled WRF–CFD Model in the Chongli Mountain Region of Hebei Province, China

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 731
Author(s):  
Shaohui Li ◽  
Xuejin Sun ◽  
Shan Zhang ◽  
Shijun Zhao ◽  
Riwei Zhang
Keyword(s):  
Wind Field ◽  
Complex Terrain ◽  
Wrf Model ◽  
Mountain Region ◽  
Weather Research And Forecasting ◽  
Cfd Model ◽  
Improved Method ◽  
Comprehensive Understanding ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd

To ensure successful hosting of the 2022 Olympic Winter Games, a comprehensive understanding of the wind field characteristics in the Chongli Mountain region is essential. The purpose of this research was to accurately simulate the microscale wind in the Chongli Mountain region. Coupling the Weather Research and Forecasting (WRF) model with a computational fluid dynamics (CFD) model is a method for simulating the microscale wind field over complex terrain. The performance of the WRF-CFD model in the Chongli Mountain region was enhanced from two aspects. First, as WRF offers multiple physical schemes, a sensitivity analysis was performed to evaluate which scheme provided the best boundary condition for CFD. Second, to solve the problem of terrain differences between the WRF and CFD models, an improved method capable of coupling these two models is proposed. The results show that these improvements can enhance the performance of the WRF-CFD model and produce a more accurate microscale simulation of the wind field in the Chongli Mountain region.

3-D periodic CFD model of the heating system in a coke oven battery

2014 ◽  
Vol 24 (4) ◽  
pp. 891-906 ◽  
Author(s):  
Jacek Smolka ◽  
Adam Fic ◽  
Andrzej J. Nowak ◽  
Ludwik Kosyrczyk
Keyword(s):  
Coke Oven ◽  
Heating System ◽  
Cfd Model ◽  
Gas Combustion ◽  
Content Type ◽  
Cfd Models ◽  
Steady State Operation ◽  
Proposed Model ◽  
Computational Fluid Dynamics Cfd ◽  
Periodic Heat

Purpose – The purpose of this paper is to develop a 3-D fully transient numerical model of the heat and fluid flow associated with the chemical reactions that occur in the heating system of the coke oven battery. As a result, the model can be used to provide data for the control system of the battery to reduce energy consumption and emissions and to obtain a product of the desired quality. Design/methodology/approach – In the proposed model, an accurate representation of the heating flue geometry, the volumetric heat sources as a result of the coke oven gas combustion, the temperature- and mole fraction-dependent properties of the gases were taken into account. The most important part of the model was the unsteady boundary condition definition that allowed the modeling of the periodic heat delivery to the two oven heating walls, both in the coking and the reversion cycles. Findings – The temperatures obtained using the computational fluid dynamics (CFD) model showed the same pattern of temperature variations as that observed in the experiments. It was also found that the quality of the temperature variation predictions was highly dependent on the radiation model settings. Originality\value – The CFD models available in the literature describe the steady or pseudo-steady state operation of the heating system of the coke oven battery. The model developed in this work fully reflects the unsteady character of this heating system. Moreover, the proposed model is prepared for coupling with a model of the coking process that occurs in the two neighboring coke oven chambers.

scholarly journals The impact of sustainability on fire safety

2021 ◽  
Author(s):  
◽  
Mohammad Musa Al-Janabi
Keyword(s):  
Fire Safety ◽  
Sensitivity Study ◽  
Mitigation Measures ◽  
Fire Dynamics ◽  
Fire Event ◽  
Use Of Resources ◽  
Smoke Spread ◽  
Double Skin ◽  
The Impact ◽  
Small Models

<p>There is a growing demand for building green buildings that are perceived to have benefits environmentally through promoting recycling, energy efficiency and efficient use of resources. The green movement has also led to innovative technologies that are focused on reducing cost. However, the fire safety industry has concerns with the use of certain technologies that create passages for smoke and fire to spread such as passive ventilation or materials that can burn severely and release large amount of toxins. The benefit of this research is to determine which features are high risk and are commonly used. The aim of this research is to investigate whether sustainable or green features have an influence on fire safety in commercial buildings and determine which feature or features would have the most significant implications for building safety in regards to tenability. A detailed investigation was done on passive ventilation such as double skin facade and the thesis also briefly discusses other green features and their implications. There were two methods used to collect data. The first was a qualitative study done through sending out surveys to fire engineers to rate and rank the most significant features that have negative implications for fire safety in reference to the New Zealand Building Code Fire Safety Section criteria and objectives. Then, a one hour interview was carried out to determine the reason behind the engineers’ choice and their perceptions. The results from the surveys and the interviews were that double skin facade and atrium were ranked the most significant. The surveys established double skin facade has the highest ranking in terms of the worst feature, and the fire engineers reinforced that double skin facade needs to be studied as there is not enough research that have gone into this feature. While atrium issues are known and mitigation measures are well developed. A subsequent analysis for only double skin facade is conducted using Fire Dynamics Simulator (FDS) because little literature is found in regards to fire safety and double skin facade. FDS was used to simulate 14 small models and 2 large models for the best and worst scenarios of DSF. Each of the 14 models, one to three parameters are changed as part of the sensitivity study to determine which parameter have the most and least effect on fire safety in term of Carbon Monoxide (CO) and visibility. The issues the engineers raised and the mitigation measures were modelled, because the engineers had stated their opinions not facts. The output results from FDS illustrated that it is essential that the system shuts off in a fire event to prevent smoke spread to upper floors, which is the same mitigation measure that were emphasised at the interviews.</p>

Impact of Heat Transfer on Contaminant Dispersion in a Public Building

2006 ◽  
Author(s):  
Sue Ellen Haupt ◽  
Robert F. Kunz ◽  
L. Joel Peltier ◽  
James J. Dreyer ◽  
Howard J. Gibeling
Keyword(s):  
Thermal Effects ◽  
Building Materials ◽  
Time Of Day ◽  
Thermal Coupling ◽  
Cfd Model ◽  
Thermal Heating ◽  
Contaminant Dispersion ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact

Computational fluid dynamics (CFD) models are effective at predicting dispersion of contaminants in or near a building. It is well known that thermal effects impact the flow around and within structures. This study assesses the importance of time of day, building materials, sky cover, etc. on the local thermal heating of a building. All these features affect the buoyancy, and thus, the resulting flow and dispersion about and inside a building. This study examines that impact through including full thermal coupling with flow calculations for an environmentally friendly building, including thermal radiation, conduction, and convection effects with a CFD model for both the interior and exterior of a building. The emphasis here is on simulating the impact of heating on contaminant dispersion.

Numerical Study on the Outdoor Wind Effects on Movement Smoke along a Corridor

2020 ◽  
Author(s):  
Brady Manescau ◽  
Khaled Chetehouna ◽  
Quentin Serra ◽  
Aijuan Wang ◽  
Eric Florentin
Keyword(s):  
Fluid Dynamics ◽  
Input Data ◽  
Numerical Study ◽  
Numerical Data ◽  
Experimental Result ◽  
Fire Dynamics ◽  
Entire Volume ◽  
Global Sensitivity ◽  
Fire Dynamics Simulator ◽  
Computational Fluid Dynamics Cfd

In this chapter, a numerical investigation is presented in order to highlight the effects of outdoor wind on smoke movements along a corridor in a compartment. For this, the Computational Fluid Dynamics (CFD) code, fire dynamics simulator (FDS), was used to model the reactive flows in interaction with outdoor wind. The wind velocity is taken between 0 and 12.12 m/s, based on the experimental result data come from the work of Li et al. was performed. From numerical data, it was found that smoke stratification state in the corridor depends on Froude number (Fr) and it can be divided into three cases: stable buoyant stratification (Fr < 0.38), unstable buoyant stratification (0.38 ≤ Fr < 0.76), and failed stratification (Fr ≥ 0.76). When Fr ≥ 0.76, smoke stratification is completely disturbed and smoke occupies the entire volume of the compartment, highlighting a risk of toxicity to people. Indeed, it was observed that the velocity of the outdoor wind influences strongly the concentration of O2, CO2, CO, and visibility in the corridor and smoke exhaust. Moreover, for the input data used in the numerical modelling, the global sensitivity analysis demonstrated that the main parameters affecting the smoke temperature near the ceiling are the mass flux of fuel and the activation energy.

scholarly journals An Investigation of the Flow Distribution Inside a Radial Sidestream Inlet of a Centrifugal Compressor

2000 ◽  
Author(s):  
Zheji Liu ◽  
D. Lee Hill ◽  
Gary Colby
Keyword(s):  
Test Data ◽  
Centrifugal Compressor ◽  
Flow Distribution ◽  
Production Test ◽  
Cfd Model ◽  
Cfd Models ◽  
Multi Stage ◽  
Final Design ◽  
Computational Fluid Dynamics Cfd ◽  
Return Channel

A radial sidestream inlet is commonly utilized in multi-stage centrifugal compressors to introduce additional gas into the mid-stage of the compressor. The flow distribution after the junction of the sidestream and the main return channel of the upstream stage can significantly affect the performance of the next stage. In this study, the mixing between the fluid from the sidestream component and the fluid from the main return channel was investigated numerically using Computational Fluid Dynamics (CFD). A variety of CFD models of different geometry, different boundary conditions, and different grid density were developed to analyze the uniformity of the flow entering the impeller of the next stage. The flow distribution difference between the sidestream CFD model and the CFD model with the sidestream coupled to the main return channel suggests that both the return channel and the sidestream have to be modeled together to get meaningful results. The results of this effort were used in conjunction with production test data to help resolve a performance shortfall of a multi-stage centrifugal compressor with sidestream injection. The test data from the final design is also provided to show the resulting improvement in head rise.

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