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COBEM 2021
26th International Congress of Mechanical Engineering
A NUMERICAL STUDY OF BUOYANCY-INDUCED SMOKE FLOW IN REAL-SCALE EMERGENCY ENCLOSED STAIRS
Submission Author:
Augusto Bolzoni , RS
Co-Authors:
Augusto Bolzoni, Angela Graeff, Felipe Roman Centeno
Presenter: Augusto Bolzoni
doi://10.26678/ABCM.COBEM2021.COB2021-0830
Abstract
Emergency enclosed stairs is one of the safety exit methods for evacuating people in a building during a fire. Brazilian standards define implementation parameters by analyzing the effective height of the building as well as its predominant occupation. The present work focuses on the analysis of an emergency enclosed stair in order to evaluate the buoyancy-induced smoke flow generated by different heat release rates of an ethanol pool fire placed at the ground floor of the building. The objective of this work is to evaluate the influence of buoyancy in the process of the smoke rising in the stairwell verifying the results of numerical simulations using the active or not activated stratification parameter. Based on these simulations, it is possible to see a flow of smoke along the stairwell due to the recirculation of hot gases between different stair landings, so it is analyzed related parameters such as velocity, temperature and pressure along the stairwell height, showing a decrease of the buoyancy driving force. For this study, numerical simulations are performed using the software Fire Dynamics Simulator (FDS), including a validation step based on an experimental work available in the literature for an 89.7 m high emergency enclosed stair, and then the analysis of the buoyancy driven smoke flow is conducted for the same geometry but changing the heat release rates of the fuel source, aiming to obtain numerical data for the parameters variation. The main conclusion is that velocity, temperature and pressure of the smoke flowing along the stairwell height are the most sensitive parameters in the buoyancy-induced phenomenon.
Keywords
FDS, Enclosed stairs, Stratification, Buoyancy, Smoke flow
