Temperature and Smoke Prediction in Structural Fires

Author(s):  
Hyeong-Jin Kim ◽  
David G. Lilley

Abstract Temperature and smoke level predictions in several rooms of a structural fire are possible with a variety of available computer codes. The accuracy and applicability of the results is greatly enhanced though the comparison of the calculations with experimental data. Experimental work assists in understanding fire behavior in structural fires. Temperature measurements at different locations during a house fire provide necessary data for the development of mathematical models, which attempt to simulate the fire on a computer. In this paper, a small 46 square meter single-level house was the subject of a complete experimental burn, with temperature measurements and fire observations during the entire burn. The CFAST computer code (Consolidated Model of Fire Growth and Smoke Transport) can be used to calculate temperatures and smoke levels in the various rooms of the house during the burn. Five fire scenarios are considered in the simulation, with progressively increasing realism regarding the actual fire specification. It is seen that calculations with the most realistic fire simulation (permitting burning in all rooms during the course of the fire) are in very good agreement with the experimental data, with regard to rate of fire spread throughout the structure, and the accuracy of the calculations of flashover, temperatures and smoke levels in each of the rooms.

Author(s):  
Hyeong-Jin Kim ◽  
David G. Lilley

Calculations (with a 10-room and a simpler 3-room simulation of the large house fire) of temperature and smoke levels in several rooms of a structural fire are possible with the CFAST computer code. The accuracy and applicability of the results is greatly enhanced though the comparison of the calculations with experimental data. Experimental work thereby assists in understanding fire behavior in structural fires. Temperature measurements at different locations during a house fire provide necessary data for the development of mathematical models, which attempt to simulate the fire on a computer. In this paper, a large 170 square meter single-level house was subject to a complete experimental burn, with temperature measurements and fire observations during the entire burn, and subsequent modeling via a detailed 10-room simulation and a simpler 3-room simulation. The CFAST (Consolidated Model of Fire Growth and Smoke Transport) computer code is used to calculate temperatures and smoke levels in the various rooms of the house during the burn (with 10 different rooms). Four fire scenarios are considered in the simulation, with increasing realism regarding the actual fire specification. A simpler calculation (with 3 different rooms) has also done to see if the similar results would be shown with the 10-room simulation. It was found that results for smoke temperature and smoke layer heights were very similar, leading to the conclusion that a 3-room simulation of a 10-room building gives adequate modeling capability of the real structural fire. Computation results give the expected trends (deduced from local point temperature measurements) of initial temperature surge and decay, peak and leveling off temperatures, especially with respect to the northwest bedroom with a closed door. The effect of whether a door of a room would have been open was investigated computationally, with results illustrating far more dangerous smoke temperature and smoke level in the room when its door is open.


2000 ◽  
Author(s):  
Hyeong-Jin Kim ◽  
David G. Lilley

Abstract The ultimate goal of this study is to improve scientific understanding of fire behavior leading to flashover in structural fires. This document summarizes important information in five topic areas: burning rates, radiant ignition, fire spread rates, ventilation limit imposed by size of opening, and flashover criteria. These are the main components related to the scientific understanding of the fire growth and flashover problem involved in real-world structural fires. Within each topic area, there are four subsections dealing with background, theory, comments, and references. Main components of the study are to develop improved mathematical simulations so as to improve the accuracy of theoretical calculation and to develop and extend the range of knowledge and modeling capability so as to extend the range of available experimental data.


2009 ◽  
Vol 16 (1) ◽  
pp. 43-46 ◽  
Author(s):  
Leszek Matuszewski

Ring thruster — a preliminary optimisation study The ring thruster is a new type of propeller, for which there is no experimental data to verify analytical design calculations. A significant feature of the ring thruster is the absence of a shaft. Propeller blades are mounted to the ring rotating inside the housing, which has the shape of a nozzle. For this reason the ring thruster is closest, with respect to both the construction and principle of operation, to the Kort nozzle propeller. The absence of a shaft and no gap between the blades and the nozzle make it impossible to fully relay on results obtained from Kort nozzle propeller examination. What is more, the already existing computer codes developed for designing Kort nozzle propellers cannot be directly used for designing ring thrusters either. That is why for this purpose a new code determining hydrodynamic characteristics based on the theory of the vortex lifting surface will be used. When using the above method, some differences between calculated and experimentally recorded results are expected to be observed. To a significant extent, the level of the torque taken by the thruster will be affected by drag of the rotating ring to which the blades are fixed. Examining a propeller equipped with a rotating ring has revealed that the expected torque increment may reach as much as a few per cent, at the comparable level of axial force (thrust). At the present stage of ring propeller investigations there is no data available on how to shape the ring propeller blades. Possible comparison calculations, done using the existing computer code, will allow, the most, the shape of the blades to be determined for preliminary tests in the cavitation tunnel and on a self-propelled model. And only the results obtained in these tests will provide opportunities for verification of preliminary design calculations. It should be stressed, however, that developing design procedures for this type of propellers will require additional optimisation calculations, with further experimental verification. And this should be the subject of separate investigations.


2007 ◽  
Vol 11 (2) ◽  
pp. 259-270 ◽  
Author(s):  
Alexander Karpov ◽  
Henry Telitsyn ◽  
Nadezhda Efimova ◽  
Victor Berdonosov ◽  
Sergey Popovich

The approach to the implementation of a computer code, based on the geographic information system, for the forest fire behavior prediction is presented. Consecutive steps are considered, which include the formulation of fire spread mathematical model, classification of vegetation fuels using the forest inventory data, approximation of fire perimeter propagation, and overall arrangement of fire simulation code. .


Author(s):  
Hyeong-Jin Kim ◽  
David G. Lilley

Abstract The ultimate goal of this study is to improve scientific understanding of fire behavior leading to flashover in structural fires. This document summarizes important information in five topic areas: burning rates, radiant ignition, fire spread rates, ventilation limit imposed by size of opening, and flashover criteria. These are the main components related to the scientific understanding of the fire growth and flashover problem involved in real-world structural fires. Within each topic area, there are four subsections dealing with background, theory, comments, and references. Main components of the study are to develop improved mathematical simulations so as to improve the accuracy of theoretical calculation and to develop and extend the range of knowledge and modeling capability so as to extend the range of available experimental data.


2020 ◽  
Vol 51 (4) ◽  
pp. 359-376
Author(s):  
Dongmei Huang ◽  
Qi Yuan ◽  
Yu Wang ◽  
YiWei Hu ◽  
Yongliang Chen ◽  
...  

2021 ◽  
Vol 13 (4) ◽  
pp. 2136
Author(s):  
Sayaka Suzuki ◽  
Samuel L. Manzello

Wildland fires and wildland urban-interface (WUI) fires have become a significant problem in recent years. The mechanisms of home ignition in WUI fires are direct flame contact, thermal radiation, and firebrand attack. Out of these three fire spread factors, firebrands are considered to be a main driving force for rapid fire spread as firebrands can fly far from the fire front and ignite structures. The limited experimental data on firebrand showers limits the ability to design the next generation of communities to resist WUI fires to these types of exposures. The objective of this paper is to summarize, compare, and reconsider the results from previous experiments, to provide new data and insights to prevent home losses from firebrands in WUI fires. Comparison of different combustible materials around homes revealed that wood decking assemblies may be ignited within similar time to mulch under certain conditions.


Author(s):  
Petya Vryashkova ◽  
Pavlin Groudev ◽  
Antoaneta Stefanova

This paper presents a comparison of MELCOR calculated results with experimental data for the QUENCH-16 experiment. The analysis for the air ingress experiment QUENCH-16 has been performed by INRNE. The calculations have been performed with MELCOR code. The QUENCH-16 experiment has been performed on 27-th of July 2011 in the frame of the EC-supported LACOMECO program. The experiments have focused on air ingress investigation into an overheated core following earlier partial oxidation in steam. QUENCH-16 has been performed with limited pre-oxidation and low air flow rate. One of the main objectives of QUENCH-16 was to examine the interaction between nitrogen and oxidized cladding during a prolonged period of oxygen starvation. The bundle is made from 20 heated fuel rod simulators arranged in two concentric rings and one unheated central fuel rod simulator, each about 2.5 m long. The tungsten heaters were surrounded by annular ZrO2 pellets to simulate the UO2 fuel. The geometry and most other bundle components are prototypical for Western-type PWRs. To improve the obtained results it has been made a series of calculations to select an appropriate initial temperature of the oxidation of the fuel bundle and modified correlation oxidation of Zircaloy with MELCOR computer code. The compared results have shown good agreement of calculated hydrogen and oxygen starvation in comparison with test data.


PEDIATRICS ◽  
1960 ◽  
Vol 26 (3) ◽  
pp. 499-499
Author(s):  
Robert J. Haggerty

I am delighted to have Dr. Jawetz again bring to the attention of your readers his definitive work on the subject of antimicrobial combinations. We certainly have no quarrel with the points he reiterates. Our choice of words, "It is not clear why these results are at variance with the experimental data of Jawetz or the clinical data of Lepper and Dowling," was probably unfortunate, for Dr. Jawetz points out why the results did differ from his experimental work.


2021 ◽  
Vol 2 (2) ◽  
pp. 36-43
Author(s):  
Evgeniy P. FIGURNOV ◽  
◽  
Yury I. ZHARKOV ◽  
Valeriy I. KHARCHEVNIKOV ◽  
◽  
...  

Methodology provided summarizes published, original and foreign theoretic and experimental data on the subject of heating and cooling of standard and shaped conductors of overhead power transmission line and uses those of them which are most affected to fundamental heat-transfer laws. Computation surface area of standard and shaped wire formulas are given. The common formula of convection heat transfer coefficient is provided, based on wind speed and direction, concerning antiicing mode. Parameters of this formula do not coincide with those existing, as they are based on experimental data on standard and shaped conductors but not on round tubes. Formula of computation of heat transfer power under the influence of solar radiation is given. Summarized formula of admissible continuous current computation is given, all the components have detailed description in the article.


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