On the fluid dynamics of the make-up inlet air and the prediction of anomalous fire dynamics in a large-scale facility

Abstract

The present paper is focused on the fluid dynamics of the make-up air at the vents in case of an atrium fire, its influence on the fire-induced conditions and the necessity of properly model it to obtain an accurate numerical prediction. For this aim, experimental data from two full-scale atrium fire tests conducted in a 20 m cubic facility, with venting conditions involving mechanical smoke exhaust and make-up air velocities larger than 1 m/s, and with different fire powers, are presented. Subsequent numerical simulations of these tests have been performed with the code Fire Dynamics Simulator v5.5.3. Two different approaches have been followed to simulate the make-up air inlet fluid dynamics, involving one domain which only considers the inside of the building and another which includes part of the outside. In the former simulations, anomalous phenomena around the fire appear, while the inclusion of the exterior domain provides with a completely different fluid dynamics inside the facility which agrees better with the experimental data. A detailed analysis of the fluid mechanics at the air inlet vents is conducted to explain these discrepancies. Finally, further simulations are performed varying the make-up area to assess the appearance of the aforementioned phenomenon. University of Jaén Department of Mechanical and Mining EngineeringFluid Mechanics Division 12 th May, 2011 Dear Professor José Torero:Please find enclosed the full-paper "On the Fluid Dynamics of the Make-Up Inlet Air and the Prediction of Anomalous Fire Dynamics in a Large-Scale Facility" for possible publication in the International Journal Fire Safety Journal. The authors have read numerous papers from your journal related to the subject tackled at the present work, which have been source of knowledge, as well as published some research papers in it, and so we think the subject of the present work could fit some of the scopes of this journal and could be of your interest. The authors guarantee the originality of the work and think that contributes to the state-of-the-art of the study of fires within big volume buildings or atria. Specifically, this work is focused on the make-up air influence which is one of the most important issues to take into account when designing smoke exhaust systems. One of the most relevant contributions of this research is the presentation of new experimental data of fires within a new full-scale fire test facility for fire models validations. Additionally, a comparison of these experimental data with predicted results from numerical simulations carried out using one of the most extensively used fire field model, FDS, is presented.Also attached you will find the figures as original graphics files.We would greatly appreciate it if you begin the revision process of the above mentioned paper.Kind regards, Dr. Gutiérrez-Montes.- ----------------------------------------------------------- ------------------------------------------------------------- Abstract:The present paper is focused on the fluid dynam...

Fire Experiments and Simulations in a Full-scale Atrium Under Transient and Asymmetric Venting Conditions

“…The experiments have been conducted at the fire atrium located in Murcia, Spain ( Figure 1a) [5][6][7][8]23]. This atrium, with dimensions of 19:5 Â 19:5 Â 17:5 m 3 , has four exhaust fans installed at 1.75 m far from the centre, represented in Figure 1b as ''A'', ''B'', ''C'' and ''D''.…”

“…Prior to the experiments presented in this paper some fire tests were carried out in the fire atrium by Gutierrez et al [5][6][7][8], which were used to validate temperatures Fire Experiments and Simulations in a Full-scale Atriumin atrium fires at the fire plume and close to walls under different HRRs using FDSv4 and FDSv5 [10]. Table 3 shows a summary of the tests performance.…”

“…Additionally, Gutierrez et al [5][6][7][8] validated some fire tests numerically with FDSv4 [9] and FDSv5 [10] with HRRs from 1.22 MW up to 2.34 MW in the fire atrium located in Spain. The studies on the smoke layer interface highlighted the importance of the make-up air supply or the exhaust flow rate conditions on its behaviour.…”

Numerical Studies on the Natural Smoke Venting of Atria

“…The atrium is in the laboratory of Technological Metal Centre. Many studies were carried out in the atrium and all of them were widely described [17][18][19][20][21].…”

Turbulent smoke flow in evacuation staircases during a high-rise residential building fire

“…FDS is a large-eddy simulation (LES) code for low-speed flows, with an emphasis on smoke and heat transport from fires. FDS is a free software developed through the National Institute of Standards and Technology of the United States Department of Commerce, which have been used in a lot of studies including combustion, heat flow and environment (Shi et al, 2007;Su et al, 2011;Sun et al, 2011;Fereres et al, 2012;Gutiérrez-Montes et al, 2012;Chi, 2013).…”