scholarly journals An Examination of the Relationship between Flow Parameters and Symptoms According to Fire Phase in a Mine Model

2017 ◽  
Vol 6 (2) ◽  
pp. 58
Author(s):  
Selçuk Keçel
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Boundary Conditions ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Ventilation System ◽  
Underground Mine ◽  
Computational Fluid Dynamics Cfd ◽  
The Relationship

This study examines the relationship between temperature, CO dispersions, symptoms, and COHb% levels accumulated in the blood on available ventilation conditions in cases of fire at point in an underground mine model. Based on operating parameters (air velocity and direction) of the ventilation system in the underground mine model, fast growing phase fire analyses were conducted according to the heat release rate (HRR) value in the range of 0-61.34MW. In fire scenarios prepared according to the hydrocarbon fuel type (C2.3H4.2O1.3), boundary conditions were calculated depending on the combustion equation considering fuel lower heating value (Qc). CO dispersions inside the tunnel were examined by transferring the time-dependent boundary conditions to the computational fluid dynamics (CFD) program.  yCO, COHb%, and COHb%/∆t changes were calculated according to the HRR value.  Findings regarding the effects of CO emission (acute and chronic poisoning), were expressed according to the HRR value. Keywords Combustion Model Design, Heat Release Rate (HRR), Carbon Monoxide emission, Symptoms and Survival Time, Computational Fluid Dynamics (CFD);

Numerical Simulation on Spreading Characteristic of Coach Fire

2012 ◽  
Vol 518-523 ◽  
pp. 1269-1272 ◽  
Author(s):  
Liang Yi ◽  
Jie Chen
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Heat Release ◽  
Heat Release Rate ◽  
Fire Protection ◽  
Release Rate ◽  
Software Package ◽  
Maximum Temperature ◽  
Peak Heat Release Rate

The aim of this work is to study the burning characteristics of coach fire. With application of computational fluid dynamics (FDS software package), coach fires caused by arson are simulated under different ventilation conditions. Variation of heat release rate (HRR) and distribution of temperature are analyzed. Peak heat release rate of coach fire caused by arson in passenger carriage can reach about 24 MW and maximum temperature in the carriage is over 1000 °C. Results of this study can be referred for fire protection and rescue design of coach.

Using Computational Fluid Dynamics Simulation to Perform Fire Investigation

2013 ◽  
Vol 393 ◽  
pp. 845-850 ◽  
Author(s):  
Mohammad Shakir Nasif ◽  
Rafat Al-Waked
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Detection System ◽  
Dynamics Simulation ◽  
Smoke Inhalation ◽  
Fire Investigation ◽  
Dynamic Simulator

Fire occurred evening 10thJuly 1989 at Terwindle Rest Home Auckland. Incident report shows that this fire resulted in seven fatalities and extensive fire damage to the building. The primary cause of the death was carbon monoxide poising from smoke inhalation. The fire started at the lounge which contained ten upholstered couches with polyurethane foam padding. Sprinkler fire protection system was not installed and the building has no smoke detection system (based on the New Zealand Building code requirement that was imposed at that time). In this study, the fire is modeled using Computational Fluid Dynamics (CFD) software FDS (Fire Dynamic Simulator). The heat release rate of the fuel burned was obtained from lab measurement of a sofa. The results were validated against the approximate time scale of the progress of the fire as it was found from the fire investigation report. It has been found that FDS can provide accurate simulation to the fire which can be used to perform fire investigation provided that the correct heat release rate of the fire used in the model.

scholarly journals Numerical simulation of performance and emission of marine diesel engine under different gravity conditions

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402092750
Author(s):  
Xiuwei Lu ◽  
Peng Geng
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Marine Diesel ◽  
Simulation Results

A computational fluid dynamics model of the marine diesel engine was established and validated, and the simulation studies were carried out using this model. Different gravity conditions were set in the computational fluid dynamics model to investigate their effect on marine diesel emissions and performance. By comparing the simulation results under different basic grid sizes, 1.2 mm was selected as the basic grid size of the computational fluid dynamics model. The model uses the experimental data including cylinder pressure, heat release rate, and nitrogen oxides (NO x) emissions to calibrate and validate the model. The simulation results are very close to the experimental data, and slight errors are also within the allowable range. In particular, when considering the heat transfer of the combustion chamber wall, the simulation results of the heat release rate are closer to the experimental data. The simulation results show that gravity has a slight effect on cylinder pressure and heat release rate, and has a certain degree of effect on fuel spray and atomization. The penetration length of the fuel is proportional to the gravity, and the maximum deviation of the Sauter mean diameter of the droplet is 25.74%. The spray and atomization process of fuel directly affects combustion and emissions. The maximum deviation of NO x emissions is 6.03%, which is reduced from 7.46 to 7.01 g/kW·h. Finally, the three-dimensional simulation results of temperature, equivalence ratio, and NO x emission of different crank angles under different gravity conditions are compared.

Numerical study of combustion characteristics and emissions of a diesel–methane dual-fuel engine for a wide range of injection timings

2018 ◽  
Vol 21 (5) ◽  
pp. 781-793 ◽  
Author(s):  
Xingyi (Hunter) Dai ◽  
Satbir Singh ◽  
Sundar R Krishnan ◽  
Kalyan K Srinivasan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Release ◽  
Combustion Chamber ◽  
Heat Release Rate ◽  
Diesel Fuel ◽  
Release Rate ◽  
Turbulent Flame ◽  
Dual Fuel ◽  
Model Predictions

Computational fluid dynamics simulations are performed to investigate the combustion and emission characteristics of a diesel/natural gas dual-fuel engine. The computational fluid dynamics model is validated against experimental measurements of cylinder pressure, heat release rate, and exhaust emissions from a single-cylinder research engine. The model predictions of in-cylinder diesel spray distribution and location of diesel ignition sites are related to the behavior observed in measured and predicted heat release rate and emissions. Various distributions of diesel fuel inside the combustion chamber are obtained by modifying the diesel injection timing and the spray included angle. Model predictions suggest that the distribution of diesel fuel in the combustion chamber has a significant impact on the characteristics of heat release rate, explaining experimental observations. Regimes of combustion in the dual-fuel engine are identified. Turbulent flame speed calculations, premixed turbulent combustion regime diagram analysis, and high-temperature front propagation speed estimation indicated that the dual-fuel combustion in this engine was supported by successive local auto-ignition and not by turbulent flame propagation.

Optimal Hardware Placement in a Minitower Computer Enclosure System

2011 ◽  
Author(s):  
M. Alfaro Cano ◽  
A. Hernandez-Guerrero ◽  
C. Rubio Arana ◽  
Aristotel Popescu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Operating Temperature ◽  
Optimal Placement ◽  
Cfd Analysis ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
The Relationship ◽  
Key Questions

One of the requirements for existing personal computers, PCs, is that the hardware inside must maintain an operating temperature as low as possible. One way to achieve that is to place the hardware components at locations with enough airflow around it. However, the relationship between the airflow and temperature of the components is unknown before they are placed at specific locations inside a PC. In this work a Computational Fluid Dynamics (CFD) analysis is coupled to a Design of Experiment (DOE) methodology to answer typical minitower key questions: a) how do the possible positions of hardware components affect their temperature?, and b) is it possible to get an optimal placement for these hardware components using the data collected by the CFD simulation results? The DOE methodology is used to optimize the analysis for a very large number of possible configurations. The results help in identifying where the efforts need to be placed in order to optimize the positioning of the hardware components for similar configurations at the designing stage. Somehow the results show that general conclusions could be drawn, but that there are not specific rules that could be applied to every configuration.

On the Use of Atmospheric Boundary Conditions for Axial-Flow Compressor Stall Simulations

2004 ◽  
Vol 127 (2) ◽  
pp. 349-351 ◽  
Author(s):  
M. Vahdati ◽  
A. I. Sayma ◽  
C. Freeman ◽  
M. Imregun
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Boundary Conditions ◽  
Hysteresis Loop ◽  
Axial Flow ◽  
Computational Domain ◽  
Computational Fluid Dynamics Cfd ◽  
Fan Blade ◽  
Flow Compressor ◽  
Speed Characteristic

This paper describes a novel way of prescribing computational fluid dynamics (CFD) boundary conditions for axial-flow compressors. The approach is based on extending the standard single passage computational domain by adding an intake upstream and a variable nozzle downstream. Such a route allows us to consider any point on a given speed characteristic by simply modifying the nozzle area, the actual boundary conditions being set to atmospheric ones in all cases. Using a fan blade, it is shown that the method not only allows going past the stall point but also captures the typical hysteresis loop behavior of compressors.

Uncertainty in Computational Fluid Dynamics

1996 ◽  
Vol 210 (1) ◽  
pp. 91-94 ◽  
Author(s):  
E H Fisher ◽  
N Rhodes
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Quality Assurance ◽  
Boundary Conditions ◽  
Error Estimation ◽  
Validation Studies ◽  
Postgraduate Training ◽  
Sources Of Uncertainty ◽  
Expert Meeting ◽  
Computational Fluid Dynamics Cfd

The Annual EPSRC/IMechE Expert Meeting brought together some 44 experts to consider sources of uncertainty in computational fluid dynamics (CFD). Presentations and discussions covered modelling, numerical solution techniques, boundary conditions, evaluation protocols and QA (quality assurance) procedures. The principal conclusions to emerge were: (a) the need for additional collaborative validation studies; (b) the desirability of introducing appropriate QA procedures, possibly based on the CFD Community Club initiative; (c) the need for additional postgraduate training, possibly based on the IGDS principle; (d) the value of continuing work in modelling and error estimation techniques for numerical schemes.

Sign in / Sign up

Export Citation Format

Share Document