The aim of this study is to illustrate some features of the water curtains generated by edge nozzles in order to offer a fire protection mechanism based on water screens. Water curtains from edge nozzles in an experimental setup are firstly investigated in terms of essential characteristics such as hydraulic patterns and heat absorption and then used as a basis for a CFD model. The setup is made with the water curtains used as a screen between a heptane pool as the fire source and an iron plate as the heat target. Several measures of temperature are taken by means of a set of thermocouples placed on the target, both in presence and in absence of the water curtains, to capture the effect of the heat reduction on the target due to the water discharge. The data collected may serve as a basis for some quantifying analysis and for comparisons with different configurations. Further research will involve thermal and hydraulic measures both necessary for preparing CFD models that may be used as a basis for applications in fire safety engineering and useful for assessment in active fire protection design.
This paper reports the fire conditions that occurred in a townhouse and the results of software simulations that were performed to provide insight on the peculiar thermal conditions that developed. Fire rescue was called by the occupants of the house when they became aware that smoky conditions were developing on the second floor. Two of the firefighters entered the bedroom where the smoke was originating from and a short time after a flame front invested them while propagating them backward into the stairwell. The post fire investigation determined that the fire started as a consequence of the smoldering combustion of material contained in a wardrobe located adjacent to one of the room walls. A simulation scenario was developed based on the information obtained on the actual building geometry, material thermal properties and the fire behaviour. The calculations that best represented the actual fire conditions indicate that the partial opening of the window and bedroom door provided outside air (oxygen) to a pre-heated, under ventilated fire compartment.
Short contact time circulating fluidized beds (CFBS Arena et al. (1993) and Tinabum et al. (1996) for two different riser configurations. A parametric analysis was performed to investigate inlet geometry influence on flow pattern along the riser. Internal tube and circumferential gas inlet produced the most promising configuration to realize optimal flow condition.
The aim of this study is to illustrate the possibilities offered by using a multi agent approach -agent based modelling (ABM) -to deepen the understanding of behavioural phenomena possibly arising in a multitude of people exposed to a sudden variation in environmental conditions. The environment, people are in, is one typical exhibition hall that is part of a larger interconnected space, such as a mall or an art centre. The normal condition is characterised by the hall with the exhibition of artworks, with people inside to enjoy the performance. Suddenly an alarm is triggered, thus defining the onset of the critical condition, activating the sequence of emergency operations. Thus, there is a change in the behaviour of the people inside the hall: from enjoying the exhibition to finding their way out.This study tries to figure out some behavioural patterns that may appear to be present among the people in real life situations similar to the one considered here. Once defined the basic quantitative assumptions in terms of spatial domain and number of people involved, a proper toolkit is used to manage the qualitative issues, such as environment modifications and people characteristics. The open source ABM platform NetLogo is adopted for modelling purposes and capturing the resulting behavioural patterns.
The aim of this study is to explore some features of a complex system arising from the interactions of a fire stream in a hub space layout, with fire protection through water curtains issued by edge nozzles activated by smoke detectors. The hub layout represents the landside part of an airport terminal, made of clusters of semi-enclosed isles open to the interconnected enclosed spaces that form a series of longitudinal paths with services and utilities. Once a fire source emits matter (smoke) and energy (enthalpy) out of one of the isle, in the absence of any fire protection barrier, the stream wanders following its buoyancy and the boundary conditions filling the available spaces inside the hub, making the occupants' conditions untenable. The design of water curtains that are activated in response to the fire onset may help to limit the dangerous spread of the fire stream and to support in the unfolding of protected paths for egress. While the activation of the water curtains in the proximity of the fire source once a threshold value is reached is the classical approach, a different design strategy is here investigated with CFD modelling based on a sequence of adaptive responses of the hub layout to the fire stream.
The aim of this study is to illustrate the advantage of using agent based models (ABM) in order to deepen the understanding of crowd phenomena and help manage design strategies and egress operations on the field.The crowd stream, recognised as a proper nonlinear system, is in fact able to produce characteristic patterns that interact with the environment in recurring shapes. In particular, the free stream and the multi-leader stream are chosen as two mostly representative patterns that develop under typical conditions in a real life egress environment, so that the ABM engineering may bring an added value also in the development of the environment layout.The first part of the study describes the features of these emerging patterns in one geometrical enclosure typical of a Mall. Such issues as queuing, clogging generation, paths of crowd spreading are, for instance, the primary goal upon which to compare the modelling. The overall outcomes, in terms of travel times and people fluxes, complete the scene.The second part of the study describes the connected evolution of these emerging patterns in an environment typical of the landside space in an Airport terminal.Such issues as people advancement, emotions transport, and change of direction are, for instance, the primary goal for the modelling. The overall outcomes of the travel times and people fluxes are the remaining issues to be assessed.The comparison between the results coming from the various ABM packages (Evac, Pathfinder) completes the study, showing how a proper choice in modelling can be based depending on the foreseen goal of the design stage.The procedure developed in this study, then, may be used and form the basis for an advanced design method that can be of practical use both in Fire Safety Engineering and in Egress Management.
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