A Novel Multiscale Methodology for Simulating Tunnel Ventilation Flows During Fires

Colella, Francesco, Rein, Guillermo, Borchiellini, Romano and Torero, Jose L. (2011) A Novel Multiscale Methodology for Simulating Tunnel Ventilation Flows During Fires. Fire Technology, 47 1: 221-253. doi:10.1007/s10694-010-0144-2

Author Colella, Francesco
Rein, Guillermo
Borchiellini, Romano
Torero, Jose L.
Title A Novel Multiscale Methodology for Simulating Tunnel Ventilation Flows During Fires
Journal name Fire Technology   Check publisher's open access policy
ISSN 0015-2684
Publication date 2011
Year available 2011
Sub-type Article (original research)
DOI 10.1007/s10694-010-0144-2
Open Access Status
Volume 47
Issue 1
Start page 221
End page 253
Total pages 33
Place of publication New York, NY United States
Publisher Springer New York LLC
Collection year 2011
Language eng
Subject 2213 Safety, Risk, Reliability and Quality
2500 Materials Science
Abstract This paper applies a novel and fast modelling approach to simulate tunnel ventilation flows during fires. The complexity and high cost of full CFD models and the inaccuracies of simplistic zone or analytical models are avoided by efficiently combining mono-dimensional (1D) and CFD (3D) modelling techniques. A simple 1D network approach is used to model tunnel regions where the flow is fully developed (far field), and a detailed CFD representation is used where flow conditions require 3D resolution (near field). This multi-scale method has previously been applied to simulate tunnel ventilation systems including jet fans, vertical shafts and portals (Colella et al., Build Environ 44(12): 2357-2367, 2009) and it is applied here to include the effect of fire. Both direct and indirect coupling strategies are investigated and compared for steady state conditions. The methodology has been applied to a modern tunnel of 7 m diameter and 1.2 km in length. Different fire scenarios ranging from 10 MW to 100 MW are investigated with a variable number of operating jet fans. Comparison of cold flow cases with fire cases provides a quantification of the fire throttling effect, which is seen to be large and to reduce the flow by more than 30% for a 100 MW fire. Emphasis has been given to the discussion of the different coupling procedures and the control of the numerical error. Compared to the full CFD solution, the maximum flow field error can be reduced to less than few percents, but providing a reduction of two orders of magnitude in computational time. The much lower computational cost is of great engineering value, especially for parametric and sensitivity studies required in the design or assessment of ventilation and fire safety systems.
Keyword Jet fans
Multiscale modelling
Ventilation systems
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Civil Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 10 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 15 times in Scopus Article | Citations
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Created: Fri, 08 Aug 2014, 10:42:49 EST by Julie Hunter on behalf of School of Civil Engineering