Thursday 25 July 2013

Article in Engineering-News Record on Travelling fires and WTC



WTC during the Sept 11 attacks. From wikipedia
An article on July 25th in the professional magazine Engineering-News Record [*] highlights recent applied research that I led on the behavior of fires inside modern buildings. 

We pioneered the design concept of 'travelling fires' which offers a paradigm shift in the structural engineering of modern buildings. The work is directly impacting the way industry designs modern infrastructure and has already been applied to design six iconic buildings in London, Manchester and Birmingham.

The research, funded by Arup while I still was at Edinburgh, accounts for one of the fastest cases of knowledge transfer to industry seen in fire science. Coincidentally, Arup has recently agreed to fund me at Imperial College London the continuation of this work with a PhD studentship.


Tuesday 2 July 2013

Keynote: When the soil burns to ash, and smouldering episodes of haze


I gave this morning the first keynote lecture at the 4th International Meeting of Fire Effects on Soil Properties, in the pretty and small city of Vilnius. The title was "Fate of Organic Matter and Pyrogenic Char in Smouldering Fires: when soils burn to ash". I have posted a copy of my slides below.

I started by making a direct reference to the ongoing haze episode in South East Asia, caused by smouldering peat megafires. Like most organic soils, peat is flammable, and dry peat is extremely flammable. This haze episode is expected to last one or two more months, and is leading to a respiratory health crisis and hundreds of millions in economic losses in the region. I then did a quick overview of some smouldering fires as a way of illustrating different fire phenomena  (1997 Indonesia, 2006 Scotland, 2008 North Carolina). After an overview of what smouldering combustion is, I then made a case for these fires to be considered the largest on Earth (the most persistent and longest leading to the highest consumption of fuel). I  reviewed the chemistry of peat fires and some of the laboratory work we have conducted to study their horizontal and vertical spread, and the role of moisture content. The last bit is collaboration with soil chemists on the signature left by smouldering fire for paleoenviromental reconstructions of peat core. I concluded with my global views; that smouldering poses a possitive feedback loop for climate change in the Earth system, and that there is a acute need for more research on the topic.



The lecture was well received with plenty of good questions during the session and the coffee break. In particular I got this question from an American scientists of what would be the best conditions for the production of charcoal/char; it really inspired me and gave me an idea for an experimental and modelling research paper: what is the heat pulse (peak and duration) that leads to the largest production of i) charcoal and ii) char. My guess is that charcoal is maximized by a strong but short pulse (akin to a quick flaming front) whereas char is maximized by the quenching of a propagating smouldering front. 


NOTE: The difference between charcoal and char is that the former, we call it alpha-char, is produced at lower temperatures such that the shape of the original biomass can be identified, and the former, we call it beta-char, is produced at higher temperatures and the shape of the original biomass cannot be identified.