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Tuesday, October 26, 2010

10 January 2011 is the Application Deadline for the International Master of Science in Fire Safety Engineering Program

The blog of the SFPE remind us that 10 January 2011 is the application deadline for the International Master of Science in Fire Safety Engineering Program (IMFSE).

The IMFSE is commonly organized by the universities of Ghent (Belgium - coordinator), Edinburgh (UK) and Lund (Sweden). This two-year educational program in the Erasmus Mundus framework provides the required knowledge for a professional fire safety engineer in a Performance Based Design environment.

The application forms, basic requirements and all other information are found on the website:

Monday, October 18, 2010

A novel methodology for simulating tunnel fires

A recent journal paper titled "A Novel Multiscale Methodology for Simulating Tunnel Ventilation Flows During Fires" has recently been published in the journal Fire Technology. Its content is presented here. This is a joint research effort between Politecnico di Torino and University of Edinburgh.

PD NOTE: This paper won this year’s Lloyd’s Science of Risk Prize in the Technology Category. The prize is awarded to academics and aims to keep the world’s leading specialist insurance market abreast of the latest academic knowledge and cutting-edge thinking. See press release by Springer.

In the past decade over four hundred people worldwide have died as a result of fires in road, rail and metro tunnels. In Europe alone, fires in tunnels have destroyed over a hundred vehicles, brought vital parts of the road network to a standstill - in some instances for years - and have cost the European economy billions of euros. Disasters like the Mont Blanc tunnel fire (1999) and the three Channel Tunnel fires (2008, 2006 and 1996) show that fire poses a serious threat.

Comprehensive risk assessments for tunnel fires are not easy to conduct. The development of the possible emergency scenarios is dependent on the combined influence of fire detection technologies, ventilation system, tunnel layout, atmospheric conditions at the portals and the presence of vehicles. Nowadays, the analysis of such complex phenomena is performed using numerical computational fluid-dynamics (CFD) tools. But CFD has a significant drawback: its requires very large computational resources (e.g., weeks or months of computing time). This limitation affects the completeness of the risk analyses because they can only be based on a limited number of possible scenarios but do not explore the wide range of possible events.

This recent paper proposes a novel multiscale modelling approach generated by coupling a three dimensional CFD model with a simple one-dimensional model. This allows for a more rational use of the computational resources. The methodology has been applied to a modern tunnel of 7 m diameter section and 1.2 km in length (similar layout to the Dartford Tunnels in London). Different ventilation scenarios are investigated involving fire sizes ranging from 10MW to 100MW.

The multiscale model is proved to be as accurate as the traditional time consuming CFD techniques but provides a reduction of two orders of magnitude in the computational time. This greatly widens the number of scenarios that can be efficiently explored. The much lower computational cost is of great engineering value, especially when conducting comprehensive risk analyses, parametric, sensitivity and redundancy studies, required in the design or assessment of ventilation and fire safety systems.

The multiscale methodology is the latest contribution to the state-of-the-art in computational methods for tunnel flow simulations. The model has been validated against experimental data of cold flow ventilation and shown to be accurate. This work was published in Building and Environment in 2009. It has also been used to provide the tunnel operator with a comprehensive assessment of the ventilation in the Dartford Tunnels, located under the River Thames about 15 miles east of London. This work was published in Tunnelling and Underground Space Technology in 2010 (open access version).

Thursday, October 14, 2010

Heron Tower and the begining of the concept of travelling fires in design

A recent article about Arup's fire design of Heron Tower (among the tallest buildings in London) appeared in The Heron Tower project won the Fire Safety Engineering design category at the Fire Excellence Awards in May 2009.

14 September 2009,

Heron Tower is a landmark in our collaboration with Arup since it led to a joint PhD thesis and a series of papers. Since 2007 we are working together to define novel design fires in similar large spaces to that in Heron Tower. We came up with the concept of "travelling fires". The initial work was presented at Interflam 2007.

Figure: Snapshot from the fire model using FDS published here. Temperature map for a 500 kW/m2 well-distributed fire on the bottom floor with top and bottom floor ventilation. The atrium acts as a chimney, linking the bottom and the top floors.

Since then, the research has advanced significantly and led to several other papers and case studies. We recently published an overview and a building survey in the magazine Fire Risk Management. The key element behind this research is the need to provide design solutions to the large parts of modern buildings that fall outside the limits set out in the Eurocodes.

The two articles published in Fire Risk Management led to an unusual number of Letters to the Editor. Letters from Mike Wood, Pilkington Group, and from Dr Kirby, Sirius Fire Safety Consultants, were received. This and this were our respective replies (our reply to Dr Kirby is also attached below).

NOTE: Thanks to Chris for mentioning the article.

On Fire Risk Management Feb 2010, Dr Kirby from Sirius Fire Safety Consultants commented on our article "Out of Range".

Our reply, Beyond Limits, in Fire Risk Management March 2010 read:
We are pleased to read the letter that Dr Kirby, from Sirius Fire Safety Consultants, wrote in response to our December cover article, "Out of range". In our article, we reported a survey of 3,080 compartments on the campus of the University of Edinburgh buildings underlining the compartment volume that falls inside of the design fire specifications of current Eurocode 1 (66 % of the older buildings, but only 8% of the most modern one). Instead of volume, Dr Kirby prefers to quote our results as % of the number of compartments (95 % of the older buildings, but only 63% of the most modern one), assuming perhaps that all compartments are equally important regardless of the very large differences in size (e.g., atria vs. single desk office). But the main conclusion of our article, that the modern building contains a very large portion of built environment outside the limits of the Eurocode, stands true no matter what survey quantity is quoted.
Dr Kirby also refers to the UK National Application Document which extends beyond the Eurocode 1 range and without limit, the use of these post-flashover design fires. We consulted this document while investigating the technical origins of the Eurocode, but after two years of searching and requests, we have not been able to find a copy of the validation work it cites. If Dr Kirby or any reader of the FRM magazine could kindly send us a copy of the validation work, we would be grateful. We hope that full details of these studies are made available to the fire research community at large for the benefit of all.
We agree that Eurocode 1 is a good document and a first step putting fire engineering into a codified form. We appreciate Dr Kirby's kind words of support for research in alternative design fires. His comments on fuel-control fires in large compartments resonate very well with our previous article in this publication ("Travel guide", November 2009, pp.12-16 by J Stern-Gottfried, G Rein and J Torero). In that article, we highlight that in large compartments, a post flashover fire is not likely to occur, but that a travelling fire spreading across the floor plate should be considered instead. We think that in the future travelling fires should also be considered as design fires and compliment the current Eurocode. Work conducted to date is available and easily accessible to the fire research community at large for the benefit of all.
Dr Guillermo Rein, BRE Centre for Fire Safety Engineering, The University of Edinburgh