Large Outdoor Fire Model Analysis

2003 ◽  
Author(s):  
Peter Vidmar ◽  
Stojan Petelin
Keyword(s):  
Fluid Dynamic ◽  
Fire Behavior ◽  
Combustion Products ◽  
Validity Of Results ◽  
Quality Of Results ◽  
Fire Model ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
The Mathematical Model

The idea behind the article is how to define fire behavior. The work is based on an analytical study of fire origin, its development and spread. Mathematical fire model called FDS (Fire Dynamic Simulator) in used in a presented work. CFD (Computational Fluid Dynamic) model using LES (Large Eddie Simulation) is used to calculate fire development and spread of combustion products in the environment. The fire source is located in the vicinity of the hazardous plant, power, chemical etc. The article present the brief background of the FDS computer program and the initial and boundary conditions used in the mathematical model. Results discuss output data and check the validity of results. The work also presents some corrections of physical model used, which influence the quality of results.

Optimization of Positive Pressure Ventiliation Tactic for Wind Driven High Rise Fires

2011 ◽  
Author(s):  
Prabodh Panindre ◽  
Sunil Kumar ◽  
Atulya Narendranath ◽  
Vinay Kanive Manjunath ◽  
Venkata Pushkar Chintaluri ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Close Agreement ◽  
Positive Pressure Ventilation ◽  
Combustion Products ◽  
Positive Pressure ◽  
High Rise ◽  
Fire Scenarios ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Fire Location

Positive Pressure Ventilation (PPV) is a firefighting tactic that can mitigate the spread of fire and the combustion products to improve the safety of firefighters and civilians in wind-driven high-rise fires than without PPV. The performance of a PPV tactic in wind-driven high-rise fires depends on various parameters that include wind speed, control of stairwell doors, number of fans, fan positions and placements, fire location etc. This paper describes the influence of these parameters on the efficacy of PPV operation that was studied by simulating wind-driven high-rise fire scenarios using computational fluid dynamics softwares Fluent 12.0 and NIST’s Fire dynamic simulator (FDS 5.0). The results obtained from Fluent and FDS found to be in close agreement with each other and have been used to optimize the PPV operation for better performance.

scholarly journals Fire Emergency Evacuation Simulation of a shopping mall using Fire Dynamic Simulator (FDS)

2017 ◽  
Vol 30 (1) ◽  
pp. 32-36 ◽  
Author(s):  
Easir A Khan ◽  
Mohammad Abir Ahmed ◽  
Emamul Haque Khan ◽  
Suvash C Majumder
Keyword(s):  
Design Pattern ◽  
Chemical Engineering ◽  
Fluid Dynamic ◽  
Emergency Evacuation ◽  
Shopping Mall ◽  
Evacuation Simulation ◽  
Evacuation Modeling ◽  
Movement Dynamics ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator

Fire accident in a shopping mall, garments factory and other labor intensive industries nowadays has become a common incident in Bangladesh and poses a great threat to life, facilities and economy of our country. In this work, fire and evacuation simulation was performed for a single stored shopping complex utilizing computational fluid dynamic techniques. Fire Dynamic Simulator with evacuation (FDS+Evac) software was used to simulate a shopping mall fire and study the effects of fire on the emergency egress process of people. The shopping mall of area 64 m2 comprises of seven rooms with a pool fire at the center of the mall is modeled for simulation. The total evacuation time (TET) for a fixed population density were estimated with the change of heat release rate, soot yield, soot density and the design pattern or geometry of shopping mall. The evacuation of agents in different time and different design pattern of the mall has been assessed using the data obtained from the simulation. FDS+Evac provides an integrating platform where the interaction between fire growth and evacuees can be taken into account by simultaneous simulation allowing a full coupling of the fire conditions and human behavior. This makes FDS is an effective tool for simulating large and high density crowds where the movement dynamics of evacuees is affected by the crowd pressure. Full scale fire experiment is often quite difficult to study the fine and crowds evacuation behavior. This paper illustrates a promising application of fire dynamic simulator (FDS+Evac) for fire and evacuation modeling to predict the total evacuation time.Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 32-36

Numerical Simulation of Fire in Logistics Center

2011 ◽  
Vol 52-54 ◽  
pp. 984-988
Author(s):  
Jing Jing Zhang ◽  
Qing Jie Qi ◽  
Chan Juan Xu
Keyword(s):  
Numerical Simulation ◽  
Life Safety ◽  
Spreading Process ◽  
Logistics Center ◽  
Fire Model ◽  
Fire Scenarios ◽  
Dynamic Simulator ◽  
Simulation Results ◽  
Fire Dynamic Simulator ◽  
Fire Spreading

Goods and shelves are closely and numerously put in the logistics center, so there are many hidden dangers. People’s life safety and property safety are threatened by fire. The key of putting out fire and evacuating people is to grasp the changes of the important parameters in the fire. In this paper the FDS (Fire Dynamic Simulator) software developed by the U. S. National Institute of Standards and Technology (NIST) is used to build a fire model and sets two fire scenarios to analyze the fire spreading process in logistics center. According to the numerical simulation results, reasonable suggestions are put forward in the end.

Resistance Monitor and Control for Vacuum Evaporation of Metals and Carbon

1976 ◽  
Vol 34 ◽  
pp. 572-573
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe ◽  
J. Michael Moseley
Keyword(s):  
Electronic Device ◽  
Point Sources ◽  
High Contrast ◽  
Variable Resistor ◽  
Quality Of Results ◽  
Low Contrast ◽  
Evaporation Source ◽  
And Control ◽  
At Will

We have designed and built an electronic device which compares the resistance of a defined area of vacuum evaporated material with a variable resistor. When the two resistances are matched, the device automatically disconnects the primary side of the substrate transformer and stops further evaporation.This approach to controlled evaporation in conjunction with the modified guns and evaporation source permits reliably reproducible multiple Pt shadow films from a single Pt wrapped carbon point source. The reproducibility from consecutive C point sources is also reliable. Furthermore, the device we have developed permits us to select a predetermined resistance so that low contrast high-resolution shadows, heavy high contrast shadows, or any grade in between can be selected at will. The reproducibility and quality of results are demonstrated in Figures 1-4 which represent evaporations at various settings of the variable resistor.

Determination of Traces Heavy Metals from Solid Residues Formed by Combustion of Lignite in Relation to Degree of Accessibility in Soil and Plants

2017 ◽  
Vol 68 (10) ◽  
pp. 2363-2366
Author(s):  
Delia Nica Badea
Keyword(s):  
Heavy Metals ◽  
Power Plant ◽  
Thermal Power ◽  
Reference Value ◽  
Combustion Products ◽  
Toxic Heavy Metals ◽  
Area Of Influence ◽  
Risk Potential

The paper evaluates the presence and content of traces of heavy metals Hg, Pb, Ni, Cd (total forms) from coal and solid combustion products, the degree of transfer and accessibility in the area of influence of a lignite power plant. The content of toxic heavy metals in residues are characterized by RE Meiji [ 1 (Pb and Hg) and REMeij �1 (Ni and Cd) for the filter ash. Pb and Ni content in the soil exceeds normal values, and Pb exceeds and alert value for sensitive soils around the residue deposit (70.20 mg.Kg-1). The degree of accessibility of the metals in plants (TF), reported at the Khan reference value (0.5), indicates a significant bioaccumulation level for the metals: Cd (1.9) and Hg (0.6) inside the deposit; Cd (0.39) at the base of the deposit, Hg (0.8) in the area of the thermal power plant. The trace levels of heavy metals analyzed by GFAAS and CVAAS (Hg), indicates a moderate risk potential for food safety and quality of life in the studied area.

scholarly journals A novel p-harmonic descent approach applied to fluid dynamic shape optimization

2021 ◽  
Author(s):  
Peter Marvin Müller ◽  
Niklas Kühl ◽  
Martin Siebenborn ◽  
Klaus Deckelnick ◽  
Michael Hinze ◽  
...  
Keyword(s):  
Shape Optimization ◽  
Large Deformations ◽  
Fluid Dynamic ◽  
Shape Optimisation ◽  
Shape Features ◽  
Floating Bodies ◽  
Novel Method ◽  
Sharp Corners ◽  
Dynamic Shape

AbstractWe introduce a novel method for the implementation of shape optimization for non-parameterized shapes in fluid dynamics applications, where we propose to use the shape derivative to determine deformation fields with the help of the $$p-$$ p - Laplacian for $$p > 2$$ p > 2 . This approach is closely related to the computation of steepest descent directions of the shape functional in the $$W^{1,\infty }-$$ W 1 , ∞ - topology and refers to the recent publication Deckelnick et al. (A novel $$W^{1,\infty}$$ W 1 , ∞ approach to shape optimisation with Lipschitz domains, 2021), where this idea is proposed. Our approach is demonstrated for shape optimization related to drag-minimal free floating bodies. The method is validated against existing approaches with respect to convergence of the optimization algorithm, the obtained shape, and regarding the quality of the computational grid after large deformations. Our numerical results strongly indicate that shape optimization related to the $$W^{1,\infty }$$ W 1 , ∞ -topology—though numerically more demanding—seems to be superior over the classical approaches invoking Hilbert space methods, concerning the convergence, the obtained shapes and the mesh quality after large deformations, in particular when the optimal shape features sharp corners.

scholarly journals Monitoring and Debugging the Quality of Results in Approximate Programs

2015 ◽  
Vol 43 (1) ◽  
pp. 399-411 ◽  
Author(s):  
Michael Ringenburg ◽  
Adrian Sampson ◽  
Isaac Ackerman ◽  
Luis Ceze ◽  
Dan Grossman
Keyword(s):  
Quality Of Results

Effects of Exit Vent Location on Fire Room Conditions During PPV

2008 ◽  
Author(s):  
Colin M. Beal ◽  
Ofodike A. Ezekoye
Keyword(s):  
Positive Pressure ◽  
Computational Simulations ◽  
Cold Flow ◽  
Flow Simulations ◽  
Advantages And Disadvantages ◽  
Experimental Compartment ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Hot Products ◽  
Vent Location

Positive Pressure Ventilation (PPV) is a widely used fire fighting tactic in which a fan is used to push hot products of fire out of a burning structure. There is a recent body of research that has been conducted regarding the advantages and disadvantages of PPV. Studies of PPV most commonly use full scale experimental fires and/or computational simulations to evaluate its effectiveness. This paper presents computational simulations that have been conducted using Fire Dynamic Simulator (FDS) version 5 to evaluate the effects of exit vent location on resulting fire room conditions during the application of PPV to a ventilation constrained fire. The simulations use a simple one room structure with an adjacent hallway. We are simulating this geometry because we are in the process of designing and constructing a similar experimental compartment. Cold flow simulations are first conducted to understand how much the presence of the fire heat release affects the flow patterns. Then, two simulations which employ PPV with different exit vent locations are compared. The differences between the two simulations are detailed and a physical explanation for the differences is presented.

scholarly journals Fluid-dynamic behavior of flaxseed fluidized and spouted bed

2017 ◽  
Vol 47 (10) ◽  
Author(s):  
Elza Brandão Santana ◽  
Maria da Conceição da Costa Valente ◽  
Lorena Gomes Corumbá ◽  
Elisangela Lima Andrade ◽  
Cristiane Maria Leal Costa ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Dynamic Behavior ◽  
Seed Treatment ◽  
Fluid Dynamic ◽  
Seed Processing ◽  
Linum Usitatissimum L ◽  
Air Temperatures ◽  
Physiological Properties ◽  
Physiological Quality

ABSTRACT: Processing of particles in a moving bed, such as a fluidized bed or a spouting bed, is commonly used in the operations of drying, coating, and granulation of particulate systems. This process has applications in the chemical, pharmaceutical and, presently, agronomical industries, especially for seed treatment/coating. This research aimed to analyze the fluid-dynamic behavior of fluidized and spouting beds with different air temperatures and loads of flaxseeds (Linum usitatissimum L.), with estimates of the fluid-dynamic parameters correlated to each process. The parameters were compared with the values obtained from classical correlations in the literature, with indications of associated percentages of deviation. Influence of fluid dynamics on the physiological quality of seeds was assessed by germination tests and the germination speed index. An analysis of the results indicated that seed processing was adequate for processing in dynamically active beds; however, temperatures above 50ºC in both beds caused significant reductions in the physiological quality of the seeds. Processing in a fluidized bed presented a smaller reduction of the physiological properties of the flaxseed.

Evaluation of Uncertainty for the Determination of Magnesium Oxide Content in Limestone by the Atomic Absorption Spectrometry

2014 ◽  
Vol 707 ◽  
pp. 283-288
Author(s):  
Xiang Dong Wen ◽  
Zheng Zhou ◽  
Wen Yang Pan ◽  
Mei Shao
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Magnesium Oxide ◽  
Influence Factors ◽  
Absorption Spectrometry ◽  
Oxide Content ◽  
Standard Solution ◽  
The Mathematical Model

According to GB/T3286.1-2012(The determination of calcium oxide and magnesium oxide content in limestone and dolomite), the mathematical model of magnesium oxide content determination in limestone by atomic absorption spectrometry was established. The various uncertainty factors of different elements for a sample were discussed and compared in the testing process. The confidence interval for the measurement result was (0.74±0.03)%,k=2 in uncertainty evaluation .The results showed that the variability of working curve and accuracy of standard solution volume for working curve were main influence factors of uncertainty. It could effectively reduce the uncertainty from the perspective of the main factors,and improve the quality of analysis.

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