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The design of smoke management systems for buildings such as atria, covered shopping malls and sports arenas require appropriate calculation methods to predict the volume of smoky gases produced in the event of a fire. The volume of smoke must be calculated in order to determine the required fan capacity or ventilator area for a smoke management system. In design, consideration is often given to entrainment of air into a smoke flow from a compartment opening that subsequently spills and rises into an adjacent atrium void. This type of plume is commonly known as a thermal spill plume. There has been much controversy over the validity of various entrainment calculation methods for the spill plume and there are considerable differences in the calculated smoke production rates using these methods. There are also scenarios involving the spill plume where design guidance is very limited. Whilst over-sizing of the required smoke exhaust can be uneconomical, under-sizing can compromise the design objectives. This work attempts to rigorously characterises thermal spill plume entrainment using new data obtained from an extensive series of 1/10th physical scale modelling experiments, supported by numerical modelling using Computational Fluid Dynamics. Spill plume behaviour and subsequent entrainment appears to be specifically dependent on the characteristics of the layer flow below spill edge, particularly in terms of the width and the depth of the flow. Plumes generated from narrow, deep layer flows entrain air at a greater rate with respect to height compared to plumes generated from wide, shallow layers. The findings of this work go some way to explain and reconcile differences in entrainment reported between previous studies. New guidance has been developed for the thermal spill plume in smoke management design, in the form of a range of new simplified design formulae,improvements to analytical calculation methods and an initial assessment of the use of numerical modelling using Computational Fluid Dynamics.

In Taiwan, the fire code is prescriptive in nature and is inappropriate to be utilized in buildings with large spaces and atria, where performance-based fire safety design method is applied. It is the goal of this dissertation to develop a design guide for this application. Through literature survey and theoretical analysis, the important parameters were induced, including: plume transport time lag, ceiling jet transport time lag, smoke entrainment rate, mechanical and natural ventilation rate. To predict smoke behavior and descending rate accurately, algebraic equations and field model were both used to calculate and compare with experimental result so that its applicability can be evaluated. Furthermore, a full-scale experiment has been conducted in the USTC campus to validate that the field model can predict the smoke behavior and descending rate accurately. Finally, the calculation models developed in this study were compiled into a guideline for fire engineering performance-based designs. Design examples were also demonstrated to explain its procedure in engineering application.

Prescribed burning (Rx) has become increasingly subjected to various regulations. Among these regulations are ordinances that restrict downwind impacts of smoke from prescribed fires. Regulations can severely limit burn managers and private landowners from using Rx as a forest management tool. This research can help us move away from these simplistic regulations, and help promote a regulatory environment in which scientific tools and knowledge are used to prohibit only activities for which the evidence suggests there will be adverse consequences. This research was divided into three parts that consisted of: (1) a pilot validation of the smoke emission model VSMOKE-GIS; (2) review of southeastern states' smoke management guidelines (SMG); and (3) a geographic analysis of Virginian's current SMG. VSMOKE-GIS showed good accuracy in predicting the PM2.5 concentration and location of the smoke plume downwind. Criteria were identified when managing Rx smoke and the strengths, weaknesses, and implications were discussed of the Rx programs. The geographic analysis demonstrated quantitatively how much area may be impacted with minimal apparent benefit. This research should provide a clearer spatial picture of the smoke management barriers associated with Rx on private woodlands in Virginia. These results should be a useful tool in developing a regulatory environment that encourages Rx when the conditions are optimal. We conclude with future recommendations for Virginia. / Master of Science

Recently, several major incidents occurred in worldwide metro and subway systems due to inadequate or inappropriate emergency procedures. In this study, the traditional and innovative metro underground stations were analyzed utilizity the CFAST and FDS computer program. A comparative study has been conducted to evaluate the smoke descending rate, and temperature distribution, etc with addressable zoned smoke control system. Dynamic egress analysis was followed to validate the NFPA 130 which was taken as the design guidelines to evaluate the evacuation time using SIMULEX program. Finally, the smoke management design and egress system was integrated, which warrants its qpplication in actual engineering designs.

ABSTRACT Almost people hurt or die because of heavy smoke when the building fires. Smoke Management is to keep the smoke in the limited zone or to change its direction and to keep the ways which the people escape bright. It is convenient for fireman to save them and to keep their life and to reduce the money loss. In the developed country of the world, smoke management design is one of the most important factors to affect egress system of the building. Effective smoke management design is to avoid the smoke diffusing or descending and to make the people have enough time to escape. The combination of smoke management and egress system using performance-based fire safety design should be developed safely and economically. In Taiwan,we haven¡¦t the proper law of smoke management and egress system about the atria of the large space. So we must progress the computer simulation about smoke management and egress system and then use full-scale experiment to perform. The major terms of the content are: 1.the optimal distribution zone analysis of smoke management of the building. 2.to design and to analyze smoke management of the atria. 3.the combination of design analysis of smoke management and egress system. 4.full-scale experimental investigation. We hope that the performance-based fire safety design method about smoke management and egress system of the large shopping mall could be the excellent model and enchance the safety of the building in Taiwan.

Many large space buildings have been built in Taiwan during the past decade and people are very concerned about the fire safety inside the large space. Therefore, a performance-based smoke management system with makeup air system has been exercised. For steady flow, the mass flow of air or smoke exhaust from the top of an atrium equals the mass flow of air entering below the smoke layer. This airflow entering the atrium is referred to as makeup air, and the makeup air can be either supplied naturally or by fan power. In this research, various full-scale hot smoke tests for makeup air systems will be performed to evaluate the temperature distribution of smoke layer and the smoke descending rate at ABRI large space fire lab in Tainan. The experimental results obtained will be utilized as an important reference to establish the code of smoke management system with makeup air system in Taiwan.

Les travaux de recherche présentés dans ce manuscrit portent sur le mécanisme de remplissage et de vidange simultanés d’un local ventilé naturellement, pouvant éventuellement être rencontré dans des situations d’incendie. L’objectif de ce travail et d'améliorer la compréhension des phénomènes physiques dominants ce mécanisme, notamment, une fois que le régime stationnaire est établi à partir d’études théoriques et expérimentales. Le travail est divisé en deux parties. Dans la première partie, nous reformulons dans un premier temps le modèle théorique de Linden et al. (1990) dans le cadre de l’approximation de Boussinesq basé sur la modélisation du panache turbulent proposé par Morton et al. (1956). Ce modèle est par la suite étendue au cadre général non-Boussineq. Dans un second temps, nous proposons un nouveau modèle basé sur les solutions exactes du panache turbulent à partir des travaux de Michaux & Vauquelin (2008). Une campagne d’essais densimétriques réalisée à échelle réduite permet ensuite d’éprouver et valider ces modèles. Dans la deuxième partie de ce mémoire, nous abordons la problématique de remplissage et de vidange dans le cadre plus spécifique de l'ingénieur de la sécurité incendie (ISI) appliquée au désenfumage. Nous commençons par présenter quelques modèles de flammes panache. Ensuite, ces modèles de flammes panache sont implémenté dans un modèle de remplissage vidange et comparés aux modèles présentés dans la première partie du manuscrit. La dernière partie porte sur une campagne d'essais thermiques à l'échelle du laboratoire. Le premier modèle théorique présenté dans la première partie est confronté aux différents résultats expérimentaux. / Research works presented in this thesis deals with the filling and simultaneous emptying of a naturally ventilated room subject to a continuous source of buoyancy, for example, the problem of natural ventilation of a room containing a fire. The aim of this work is to improve from a theoretical and experimental point of view the understanding of the dominant physical phenomena of this mechanism, especially once the stationary state is reached. This work is divided into two parts. In the first "academic" part, we revisit the theoretical model developed by Linden et al. (1990) under the Boussinesq approximation, based on Morton et al. (1956) turbulent plume assumption. This model is then extended in the general non-Boussinesq case and a parametric study highlights the influence of the governing parameters on which it depends. Secondly, we propose a new model based on the exact turbulent plume solutions proposed by Michaux & Vauquelin (2008). Laboratory experiments were also conducted using a light gas air-helium mixture in order to test and validate these models. In the second part of this work, we address the problem of filling and simultaneous emptying in the more specific context of fire safety engineering applied to smoke management. We begin by presenting some engineering relations for fire plumes, which we implement in a filling emptying model. A comparison is then made between these models and those presented in the first part of the manuscript. The last part deals with a fire test campaign at the laboratory scale and on full-scale. The first theoretical model presented in the first part is confronted with different experimental results.

A series of numerical modeling studies were conducted to characterize the mass flow rates in balcony spill plumes (BSP), a type of buoyant fire plume occurring in atria. The variation of BSP mass flow rate as a function of elevation, fire size and fire compartment geometry was examined both numerically and experimentally. A new method for estimation of BSP mass flow rates, appropriate for design of smoke management systems in high-elevation atria, was developed based on simulations of BSP mass flow rate. An experimental program conducted in a 12 m high atrium measured BSP mass flow rates as well as temperatures in the fire compartment and atrium. This data was used to evaluate CFD models of the fire compartment and atrium in the experimental facility. These were implemented using the Fire Dynamics Simulator (FDS) software. The models were extended to investigate BSP behaviour at elevations up to 50 m. The removal of atrium walls in the model to allow free development of the BSP is a unique approach among published numerical modeling studies of BSP behaviour. The high-elevation CFD model was used to perform a parametric study of BSP mass flow rate as a function of elevation, fire size and fire compartment geometry. Predictions of BSP mass flow rate from this study extend to 50 m above the atrium floor, extending the range of elevations represented in the published experimental data (<= 9 m). Data from the parametric study was used to develop a new method for estimation of BSP mass flow rates at high elevations. BSP mass flow rates estimated using the new method are shown to be bounded by values estimated using existing methods based on low-elevation experimental data.

A series of numerical modeling studies were conducted to characterize the mass flow rates in balcony spill plumes (BSP), a type of buoyant fire plume occurring in atria. The variation of BSP mass flow rate as a function of elevation, fire size and fire compartment geometry was examined both numerically and experimentally. A new method for estimation of BSP mass flow rates, appropriate for design of smoke management systems in high-elevation atria, was developed based on simulations of BSP mass flow rate. An experimental program conducted in a 12 m high atrium measured BSP mass flow rates as well as temperatures in the fire compartment and atrium. This data was used to evaluate CFD models of the fire compartment and atrium in the experimental facility. These were implemented using the Fire Dynamics Simulator (FDS) software. The models were extended to investigate BSP behaviour at elevations up to 50 m. The removal of atrium walls in the model to allow free development of the BSP is a unique approach among published numerical modeling studies of BSP behaviour. The high-elevation CFD model was used to perform a parametric study of BSP mass flow rate as a function of elevation, fire size and fire compartment geometry. Predictions of BSP mass flow rate from this study extend to 50 m above the atrium floor, extending the range of elevations represented in the published experimental data (<= 9 m). Data from the parametric study was used to develop a new method for estimation of BSP mass flow rates at high elevations. BSP mass flow rates estimated using the new method are shown to be bounded by values estimated using existing methods based on low-elevation experimental data.