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Saturday, July 31, 2010

2009 Victorian Bushfires Royal Commission releases final report on "Black Saturday"

The 2009 Victorian Bushfires Royal Commission has just released its final report. The Commission conducted an extensive investigation into the causes of, the preparation for, the response to and the impact of the fires that burned throughout Victoria in late January and February 2009 and caused the death of 173 people.

The report is written and released openly and worldwide to ensure that lessons from the disaster are clearly defined and learnt:

The Final Report is the Summary document and the other four individual volumes
address the following topics:
Volume 1 - The Fires and the Fire Related Deaths,
Volume 2 - Fire Preparation, Response and Recovery,
Volume 3 - Establishment and Operation of the Commission,
Volume 4 - The Statements of Lay Witnesses.

Friday, July 30, 2010

Research and the release rate of FDS versions

I have recently posted in the Discussion Group site for FDS and Smokeview some questions related to the release rate of FDS versions that I would like to post here as well.

Note: Fire Dynamics Simulator (FDS) is a computational fluid dynamics model of fire-driven fluid flow developed by NIST.

First, note that I am not a code developer but an user. I am a particular type of user: a researcher. An academic who studies methodologies to use some of the tools available to fire safety engineers. Hopefully I have helped or will help to develop the state of the art in fire modelling. I certainly support improvements to FDS and greatly admire the work of the FDS developers team.

For the last two years I am facing two problems stemming from the different versions of FDS that are released with some frequency. Research (my research at least) has a characteristic time that seems to be significantly longer that the time between version releases. This means that when we start a research project on modelling that includes FDS we use the newest version available but by the time the work is finishing and concluding, there are one or two new versions of FDS available. Note: PhD thesis in the UK last for three or four years.

This has led to these issues in my research group:

I - Different results from different versions
We have accidentally observed two times already (in two different PhD thesis work) that the same input file produces significantly different results in different but consecutive versions of FDS (eg v5.2.0, v5.2.5 and v5.3.0). In one case it took us months to figure out the problem. Both of these problems were discussed in due time in the FDS forum. My personal recommendation to my students is that they fix the FDS version of their interest at the beginning of the project and stay with it until the very end of the thesis.

I wonder if other researchers would like to express their views on this issue?

II - Peer reviewed of FDS results
We have had reviewers complaining and requesting rejection of our modelling papers because results are not in the latest version of FDS. NOTE: just the review process in fire and combustion typically takes anything from 3 to 16 months.

About modelling work on the Dalmarnock Fire Tests (Chp 2 of this thesis), one anonymous reviewer recently said "Given that [version] 5 has significant changes in the combustion model and other submodels, there is no value to the community in publishing a paper on FDS 4 unless the paper can demonstrate that the conclusions on FDS performance will remain valid for the current version and versions under active development".

To demonstrate that the conclusions of the work apply to the newest version of FDS effectively implies repeating the thesis work. This is not affordable in most cases, at least not for my group. Should academics fear every new version of FDS because it means one extra year of work for PhD students?

I wonder if other researchers would like to express their views on this issue?

III - Corollary
Following from issues I and II, I am confronted with the question, what happens with buildings which design was aided and approved using previous versions of FDS. What are the implications to forensic investigations that reached conclusions in court using a previous version of FDS?

Tuesday, July 27, 2010

Starting early with fire experiments

As part of their science education programme the children at Chapter One childcare on Drum Street in Gilmerton spent the morning learning about fire and watching some fire experiments. Dr Stephen Welch from the fire group demonstrated key phenomena governing fire behaviour, i.e. effects of air and water, via the Fire Tornado experiment and an investigation of water suppression of a small pool fire. At the end of the demonstrations all of the children were aware of the possibilities of fire doing unexpected and dangerous things, and they all know that children should NEVER play with fire!

Thursday, July 22, 2010

Combustion Institute British Spring Meeting 2010 - Combustion Phenomena in Fire Science

One-Day Meeting on Combustion Phenomena in Fire Science

Combustion Institute British Section: Spring Meeting 2010

Minutes by Stephen Welch, July 2010
BRE Centre for Fire Safety Engineering, The University of Edinburgh

Seven invited speakers from home and abroad represented research interests spanning experimental studies and modelling of fire phenomena.  The meeting opened with a good context setting talk on “Enclosure fires modelling: where are we and where are we going?”, by Prof Bart Merci of Ghent University.  The capabilities of models are progressively advancing but equally if not more important is the knowledge of the user.  Options to increase knowledge of FSE were discussed and the value of Masters programmes in Fire Safety Engineering emphasised. The complexity of fire phenomena and the strong dependence of fire development on details of the input must be recognised. The need for systematic validation exercises working up from simple cases, and recognising measurement uncertainties, remains vital.  Discussion focussed on the problem of models validated for benchscale scenarios being misused in other large-scale applications.

The current limits of our knowledge became rapidly apparent in the next talk on the Buncefield incident by Dougal Drysdale, emeritus professor at Edinburgh University.  Lavishly illustrated by impressive images of tank fires and explosion aftermath, Dougal highlighted a number of thought-provoking aspects of the incident: the possibility that the vapour had been ignited by the pumps turned on to disperse it, with initially puzzling damage features elucidated as pertaining to the reverse flow in the rarefaction wave, all pointing at the pumphouse, and the environmental impact of the use of remaining stocks of old foam concentrate, which had been banned from further use.  The severity and exact nature of the explosion has still not been satisfactorily resolved via modelling studies that were completed with Cartesian hedgerows. Despite opinions expressed at the time that this incident was unique and could never happen again Dougal noted that there have recently been two more of a similar nature.  Hedgerows may indeed have had a role in providing turbulence generation mechanisms and perhaps we need to consider their removal!

Dove-tailing nicely with Dougal’s conclusions, Dr Savio Vianna of Cambridge University picked up the theme of dealing with complex geometries in accidental explosion modelling.  Peak pressures have been well predicted in a range of applications using a Modified Porosity Distributed Resistance (MPDR) model for approximating the flow effects due to complex obstructions (thus potentially of value for Dougal’s hedgerows?!).  Work is ongoing on addressing further aspects of the combustion modelling and the impact of suppression phenomena via deluge and micromist systems.

With another slick progression Prof Kai Luo of Southampton University then took us deeper into the challenges of modelling fire suppression.  Liquid phase effects tend to invalidate most of our existing modelling tools for diffusion flames and attempting to include them we are immediately confronted by severe computational challenges.  Nevertheless, by adopting an Eulerian-Lagrangian Approach with an LES/DNS framework valuable insights into mechanisms have now been achieved – highlighting the need to supply sufficiently small drops which are able to effectively reach the reaction zones and the fact that the cooling effects are dominant over dilution and direct kinetic impacts.  Thus fine mists with large evaporation enthalpies will tend to be most effective but optimum droplet size is dependent on the nature of the fire flows.

Having exhausted the topic of suppression we returned to fluid dynamics and the particular problems of entrainment of air into thermal spill plumes, studied in great detail by Dr Roger Harrison in his work at the University of Canterbury.  These are very relevant practical problems for design of large public spaces but hitherto the spill plume formulae have been constrained by insufficient empirical knowledge, and the application of advanced numerical models, i.e. CFD, limited by other uncertainties.  It was found that spill plume behaviour and entrainment are dependent on the characteristics of the layer flow below the spill edge.  Roger’s work has also resulted in a range of new and improved simplified design formulae for a variety of spill plume scenarios and new guidance on the use of CFD models for these applications.

Coming back to fundamental fire phenomena, Prof John Griffiths of Leeds University addressed the topic of lagging fires, a common problem in industrial environments when potentially flammable fluids leak from pipe work into the surrounding insulation material. Such fires may have devasting consequences, and are neglected at our peril!  The participating phenomena are highly complex, but John’s experimental, numerical and theoretical investigations have revealed the role of different processes related to the nature of the combustion (gas or liquid phase) and the dependence on the fluid properties in interaction with the heating environment, i.e. the energetic effects of vaporisation and the possibility of fluid and vapour movement and recondensation within the porous media. Thus fuel volatility, overlooked in previous studies with mainly involatile liquids, is a key parameter.

The day concluded with a wide-ranging talk on Forest Fire Research by Prof Domingos Viegas of the University of Coimbra.  We were informed of the fundamental experimental research on fire spread dependencies which have clarified basic sensitivities to effects of wind and slope.  At full-scale level the role of convection is vital.  The mechanisms involved in spot fires have been individually examined and fire tornados have been studied in the lab and at full-scale.  The concept of eruptive fire behaviour was described, and the extreme dangers arising from sudden transitions in fire development illustrated by a number of sobering case studies.  The talk concluded with lessons learned from the Australian fires in Victoria in 2009, which claimed 173 lives and destroyed 4000 km2 within 10 hours. 

All of the talks (downloadable*) raised our awareness of the potentially serious consequences of fire in various arenas and the challenge to the fire community in furthering our understanding and knowledge of the fundamental underpinning fire phenomena.  We add to this our responsibility to educate and inform and clearly we have our work cut out and much to do.  In concluding the meeting the awards committee recognised some of the outstanding work already being done in these areas in conferring the best poster awards to  Dr A Snegirev of Saint-Petersburg State Polytechnic University, for his work on modelling spray fires, and to Jamie Stern-Gottfried et al. of Edinburgh University/Arup, for his studies of non-homogeneous fire environments.

Minutes by Stephen Welch, July 2010
BRE Centre for Fire Safety Engineering, The University of Edinburgh

PROGRAMME of Invited Speakers:


Registration, coffee/tea and poster setup


Ghent University
Enclosure fires modelling

University of Edinburgh
2005 Buncefield oil depot explosions

University of Cambridge
Accidental explosions modelling

Lunch and Poster Session

University of Southampton
Fire suppression modelling

University of Canterbury
Fire plume experiments

Coffee/tea and Poster Session

University of Leeds
Lagging fires: Experimental, numerical and theoretical investigations.

University of Coimbra
Forest fires research

Best Poster Awards


Meeting Co-sponsored by IOP Combustion Physics Group

Wednesday, July 21, 2010

One-day Conference: Emerging Technologies in Combustion, 29 Sept

Emerging Technologies in Combustion
29 September 2010
Heriot-Watt University, Edinburgh


The Autumn meeting of IOP Combustion Physics Group will take place at Heriot-Watt University, Edinburgh, on 29 September 2010. This one-day meeting will cover current and emerging technologies in Combustion in industry and academia. The topics will include, Clean Combustion; Coal Combustion; Carbon Capture and Storage and biochar; Underground Coal Gasification; Methane Hydrate; and Soil contaminant remediation.

Organised by the IOP Combustion Physics Group
(co-sponsored by the Combustion Institute British Section)

More information here.

09:15Registration and Coffee
09:45Welcome to HWU, Edinburgh, Prof. James Ritchie
Morning Section
Section Chair: Professor David Fowler, NERC, Edinburgh
10:00Clean Combustion: The Challenge!Prof Doug Greenhalgh, Heriot-Watt University
10:30Topic: To be decided
Mr. Richard Dennis, Doosan Babcock
11:00Carbon Capture and Storage: current status and implications for combustion technologies Prof. Jon Gibbins, University Edinburgh
11:45Methane Hydrate: The Burning SnowballProf. Bahman Tohidi (Heriot-Watt University)
12:15Discussion, Chair: Prof. David Fowler
Afternoon section
Session Chair: Dr. Guillermo Rein (University of Edinburgh)
13:40Underground Coal GasificationDr Richard Marsh, Cardiff University
14:10Biochar as a Climate Change Mitigation Technology and Adaptation measure - promises and challenges of its deploymentDr. Ondrej Masek, University of Edinburgh
14:40Combustion Technology for the Remediation of Industrial Soil Pollution: Environmental Benefits from Combustion ScienceDr Christine Switzer, University of Strathclyde
15:10The combustion of fossil fuels in novel power cycles capable of capturing CO2 suitable for sequestrationDr. John Dennis, University of Cambridge
15:40Discussion section
Chair: Dr. Guillermo Rein, University of Edinburgh
16:10Tea, Close

Sunday, July 11, 2010

Prof Torero elected Fellow of the Royal Academy of Engineering

Congratulations to Prof Jose Torero on being elected a Fellow of the Royal Academy of Engineering (FREng).  FREngs are UK's leading engineers and a unique national resource.

Prof Mike Forde said "This is an incredibly competitive award and reflects Jose's personal engineering achievements related to advances in structural behaviour in fire, material flammibility, tunnel fire safety,  contaminant remediation technology and sensor driven emergency response. It also recognises Jose's engineering contributions as an advisor to industry and governments worldwide".

Official announcement can be read here: Academy elects 'unique national resource' to assist in economic recovery, RAEng News Release, 08 July 2010

Saturday, July 10, 2010

Conference Report: Interflam 2010 at Nottingham

The 12th Interflam conference took place from 5 to 7th July 2010 at Nottingham, UK. Some 130 papers and over 70 poster paper were presented. It was well attended by individuals both from research institutions and industry.

Edinburgh presented four papers and one poster, and was represented by
David Rush, Nicolas Bal, Jamie Stern-Gottfried, Freddy Jervis, Luke Bisby and Guillermo Rein.

There was only one plenary talk, the Keynote Lecture by M Janssens that opened the conference on Monday morning. It focused on Interflam's past, with plenty of statistics about old papers and historical topics. It was a lost opportunity to inspire the incoming generation of researchers.

There were many excellent papers presented, specially on pyrolysis modelling and compartment fires. But overall, the best element at Interflam was the lively discussions experienced at most sessions.

Event organisation was flawless and the venue very comfortable. Only complains mentioned were the low quality accommodations (student dorms) and the very high conference fees.