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Modelowanie wpływu warunków środowiska pożarowego na dostępny czas ewakuacji

Kita Łukasz, Krauze Andrzej, Boroń Sylwia

Materiały Budowlane

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2021

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nr 7

26--28

PL

W artykule przedstawiono analizę numeryczną wpływu czynników towarzyszących występowaniu pożaru na dostępny czas ewakuacji, na podstawie przyjętego scenariusza pożarowego w wybranym pomieszczeniu. Środowisko pożaru modelowano za pomocą zaawansowanych metod numerycznych CFD w programie FDS. Na podstawie wartości krytycznej zasięgu widzialności określony został czas, po którym użytkownicy nie byli w stanie ewakuować się z analizowanego pomieszczenia objętego pożarem w sposób bezpieczny dla ich zdrowia i życia. Dokonano oceny potencjału aplikacyjnego oprogramowania FDS do przeprowadzenia analiz związanych z wpływem warunków pożaru na dostępny czas ewakuacji w obiekcie.

EN

In the article a numerical analysis of the influence of factors accompanying the occurrence of fire for the available evacuation time was presented, based on the adopted fire scenario in a selected room. The fire environment modeling was performed using advanced numerical methods CFD in the FDS software. On the basis of the critical value of the visibility range, the time after which the users were not able to evacuate from the analyzed room under fire in a safe manner for their health and life was determined. The application potential of the FDS software was assessed for carrying out analyzes related to the impact of fire conditions on the available evacuation time in the facility.

2

The Critical Conditions and Kinetics Required for Dynamic Recrystallization in a High-Carbon Tool Steel

Zhang Yong-Ji, Wu Guang-Lian, Wu Shang-Wen

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 1

119--125

EN

A hot compression test was conducted on a Gleeble-3500 thermo-simulation machine to study the critical conditions and kinetics of dynamic recrystallization in a high-carbon tool steel. The critical conditions for the initiation of dynamic recrystallization were determined using the working-hardening theory. The quantitative relationship between the critical characteristics of dynamic recrystallization and the hot deformation parameters were elucidated based on two different methods: the apparent method and physically based method. It was found that the two methods both have high applicability for the investigated steel, but the physically-based method needs less parameters and makes it possible to study the effect of different factors. A dynamic recrystallization kinetics model was used to calculate the recrystallization volume fraction under different conditions. The calculation results matched well with the data obtained from the flow curves.

3

The influence of methane addition on the propagation of hydrogen-methane-air detonation in partially confined geometry

Cieślak I., Rudy W., Teodorczyk A.

Archivum Combustionis

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2016

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Vol. 36 nr 2

121--130

EN

The aim of this study was to perform the experiments of detonation propagating in stoichiometric hydrogen-methane-air mixtures in partially confined geometry. The experiments were done to examine the influence of the methane fraction in fuel on the ability of detonation to propagate. Four types of gaseous mixture composition were used: 0%, 2.5%, 5% and 10% of methane in fuel. The critical height h* was found for each mixture. Furthermore, by using the smoked-foil technique the detonation cell sizes λwere measured and the correlations h*/λ were calculated for each mixture. The results showed that detonation of hydrogen-methane-air mixture may propagate in partially confined geometry only when the channel height is at least equal to 1 cell size which is similar to the condition for planar detonation propagating in closed, rectangular channel. The research showed high influence of the boundary dividing the flammable layer from the air layer.

4

Ochrona przeciwpożarowa. Oddziaływania pożaru na użytkowników i konstrukcję. Część 1

Kosiorek M.

Builder

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2015

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R.19, nr 10

86--90

PL

W czasie trwania dwóch pierwszych faz pożaru możliwa jest ewakuacja, a oddziaływania na konstrukcję budynku (z wyjątkiem konstrukcji drewnianych) są pomijalne. Po rozgorzeniu w pożarze rozwiniętym temperatura w ciągu kilku minut osiąga kilkaset stopni Celsjusza. Z tą fazą pożaru związana jest odporność ogniowa konstrukcji lub odporność pożarowa. Cykl artykułów, który rozpoczynamy, będzie dotyczył konstrukcji w warunkach pożaru.

EN

The article discusses the fire environment and fire safety critical condition. However, the fire environment has an action on the structure and the users, different properties of this environment or different action levels are considered in both cases. Critical structure condition and critical condition of the environment due to its action on the users are also separated in time and space. Because of this the methodology of analyzing both the critical conditions is also different; the structure is designed taking into consideration the expected actions, whereas when taking users into consideration, the building has to be designed so that in a specific time in some locations the critical environment condition will not be exceeded. The structure can be designed taking into consideration the expected thermal actions of a fire environment, and from he viewpoint of the users, the environment must be adapted in such a way that it will be possible to leave the threatened area within specific time.

5

Oddymianie obiektów po nowelizacji przepisów techniczno-budowlanych

Brzezińska D.

Ciepłownictwo, Ogrzewnictwo, Wentylacja

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2010

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T. 41, nr 7-8

279-282

PL

Znowelizowane w 2009 r. Rozporządzenie w sprawie warunków technicznych jakim powinny odpowiadać budynki i ich usytuowanie wprowadziły znaczące zmiany w sposobie podejścia do projektowania instalacji oddymiania w obiektach budowlanych. Wśród projektantów rodzi to obecnie wiele trudności, z których niektóre spróbujemy rozwiązać w cyklu artykułów omawiających techniki obliczeniowe, poparte przykładami, dla kilku grup powszechnie występujących budynków. Pierwsza część stanowi wstęp do cyklu i omawia ogólny sposób podejścia do problemu oraz zakres zmian wprowadzonych do przepisów.

EN

The revised in 2009 regulations on technical conditions to be met by buildings and their location have introduced significant changes in the treatment of the smoke exhaust system design in the buildings. The regulations arouse many difficulties among the designers.The author’s proposal tries to solve some problems in a series of articles discussing the computational techniques, supported by examples for several groups of commonly occurring buildings. The first part provides an introduction to the cycle and discusses the general approach to the problem including the scope of amendments to the legislation.

6

Application of real-time kinematic GPS method in critical conditions

Bogusz J., Kujawa L., Rogowski J., Szołucha M., Korcz M., Leszczyński W.

Reports on Geodesy

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2001

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z. 2/57

175-183

EN

This paper deals with different application of RTK-GPS methods for precise monitoring of the moving objects of different kind. The high accuracy of this method (which actually reaches a few centimetres) makes the possibility for much wider application as used until now. The authors performed the tests aimed at the investigation of the RTK measurements accuracy made in critical conditions (obstructions, multipath, etc.). This paper describes results of such tests, which were performed using manmanned models of VLLC in Warsaw and practice determination of the accuracy of the real-time kinematic GPS. It also presents the contemporary methods of the multipath elimination and the results of their practical application.

7

Linear disturbances and critical conditions in one – dimensional flow of constans media

Bilicki Z., Downar-Zapolski P.

Zeszyty Naukowe Instytutu Maszyn Przepływowych Polskiej Akademii Nauk w Gdańsku

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1999

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nr 505/1464

63--83

EN

This paper investigates the influence of inertial processes on the of small disturbances and the properties of the critical flow of continuos media. The intertial processes may stem from heat and mass exchange on the component two-phase flow. Since almost all the models of a flow medium take the form of hyperbolic, quasi-linear systems of partial-differential equations, the mathematical background of the critical flow and the propagation of linear disturbances, for this type of equations, is presented. The problem of discontinuous solutions and its possible influence on the critical flow has been discussed Finally, some important differences concerning linear waves in dispersive and non-dispersive systems are discussed.