Fire Safety Engineering at Aalto

In Dec 2018, Hadi Bordbar gave a keynote speech at the 9th National Conference on CFD Applications in Chemical and Petroleum Industries hosted by the University of Tehran. The title of the speech was High Fidelity Modeling of Spectral Thermal Radiation in Combustion Systems. He also ran a half day workshop of numerical modeling of thermal radiation in combustion systems in the University of Tehran.

The same seminar was also given in Sharif University of Technology. The event was hosted by the research group of Prof. Masood Darbandi in Dep. of Aerospace Engineering and Center for Development of Modern Energy Systems.

Posted by Hadi

Hadi Bordbar hosted “BRING THE HEAT” seminar in Aalto presented by FLIR in partnership with Infradex. Representatives of these two companies exhibited their up-to-date thermal imaging technologies and cameras during a 2 hours seminar. The event was free and open to all the Aalto’s employees and students. The participants received the certificate of attendance.

         Thermal bridge around a window

   Thermal portrait of some members of Aalto Fire Safety Eng. Group

from left: Rahul Janardhan, Aleksi Rinta-Paavola, Hadi Bordbar, Deepak Paudel, Simo Hostikka

The companies awarded a thermal imaging camera to Aalto Fire Safety Eng. group in compensations of Hadi Bordbar’s efforts in organizing the event. Here is a video of its unboxing ceremony 🙂

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We had a pleasure to welcome new members and short-term visitors to the FSE team:

Ada Malagnino (right) from the University of Salento, Italy, is visiting our group for six months. Her PhD topic deals with the management of safety design and fire safety assessment during building renovations. The focus is on the utilization of Building Information Modelling on fire safety management.

Guilherme Fraga (left) is a PhD student at Universidade Federal Do Rio Grande Do Sul,  Brazil. His research topic is turbulence-radiation interaction, and he has already implemented different spectral models of radiation medium into FDS. The purpose os Guilherme’s short visit is to make some of these models available for all FDS users, and to investigate if we can improve the accuracy of radiation predictions with WSGG models.

Eetu Veikkanen (middle) started his MSc thesis on the effectiveness of fire sprinklers in protecting the life safety of patients in hospital fires. He will analyze the data that we collected with VTT in fall 2018 in Sysmä.

Posted by Simo Hostikka

New things are coming! We are hiring two new doctoral students to the team:

First is about the numerical simulation of spectral thermal radiation in condenced phase materials. Hadi will be the advisor for this thesis – the best possible person you can imagine!
https://www.aalto.fi/careers/doctoral-candidate-in-numerical-modelling-of-thermal-radiation-in-fires

The second one will contribute to the international OECD PRISME3 fire test project by performing CFD simulations of the cable tunnel fires.
https://www.aalto.fi/careers/doctoral-candidate-in-numerical-simulation-of-fire-spreading-on-electrical-cables

Posted by Simo Hostikka

The Nordic Fire and Safety Days was held in Trondheim, Norway on 7.-8. June this time. From the Aalto fire safety engineering group, Prof. Simo Hostikka and doctoral students Aleksi Rinta-Paavola, Deepak Paudel and Teemu Isojärvi attended the conference. Prof. Hostikka had the honor of giving the first keynote lecture, with title “Handling overpressure and ventilation in modern building fires”, and discussing the risk of dangerous overpressure development when accidental fires occur in modern airtight buildings.

Aleksi Rinta-Paavola was awarded the prize for this year’s best fire science master’s thesis (congratulations!), and gave a presentation “Numerical simulation of passive fire protection systems”.

Aleksi Rinta-Paavola receiving his Master’s thesis award at NFSD 2018.

Deepak Paudel presented his work in a talk titled “Modeling uncertainty in the prediction of wall temperature in compartment fires”. In his presentation, Deepak showed that we can take into account the model uncertainty when we use deterministic models for probabilistic fire risk assessments.

Teemu Isojärvi had a presentation titled “Radiation transmittance through the liquid phase in an n-heptane pool fire“. The work is, to our knowledge, the first time when k-distribution method is used for liquid material radiation calculations.

Some of the presentations will be shared publicly in ResearchGate.

The event was a great opportunity to connect with other people working on either the practical or scientific aspects of fire safety. Now looking forward to the ESFSS 2018 symposium, to be held in Nancy, France in September.

Posted by rahul

The fire safety engineering group visited the historic Suomenlinna fortress (UNESCO World heritage site) on 11th June. It was fun, exploring the tunnels and basking in the evening sun by the coast, as we watched the cruise set sail towards Stockholm.

PC: Hadi Bordbar, Deepak Paudel & Tito Adibaskoro

Posted by rahul

Today, 19th January,  Topi Sikanen defended his dissertation on “Simulation of transport, evaporation, and combustion of liquids in large-scale fire incidents” supervised by Prof. Simo Hostikka. The opponent for his defence was Prof. Jennifer Wen from University of Warwick, UK. Congratulations to Topi Sikanen.

Topi Sikanen’s doctoral defence at the Department of Civil Engineering, Aalto University.

Left to right: Prof. Jennifer Wen, Topi Sikanen and Prof. Simo Hostikka

The dissertation can be accessed through this link:  https://aaltodoc.aalto.fi/handle/123456789/29568  

Posted by rahul

Aalto fire research group at the IAFSS 2017 symposium banquet.Left to Right: Dr. Kaiyuan Li, Rahul Janardhan, Prof. Simo Hostikka, Topi Sikanen and Deepak Paudel

The 12th edition of the triennial IAFSS Symposium was held at Lund University, Sweden this year. Four members of the Aalto fire research group, headed by Prof. Simo Hostikka, were present at the symposium to share their research with the fire science community.

Prof. Hostikka spoke about “Heat and mass transfer in the condensed phase” in the Condensed phase subgroup of the MacFP workshop.

Dr Kaiyuan Li presented his paper about “Char cracking of MDF due to thermal shock effect induced pyrolysis shrinkage“.

Rahul Janardhan, PhD student, presented the paper from the PAHAHUPA project titled, “Fire induced pressure and smoke spreading in mechanically ventilated buildings with air tight envelopes“.

Deepak Paudel, PhD student, presented the poster “Uncertainties in the prediction of
fire-barrier temperature: Simulation and validation of a fire experiment”. 

Also, Topi Sikanen from VTT Technical Research Centre of Finland presented his paper on “Predicting the heat release rates of liquid pool fires in mechanically ventilated compartments“.

Posted by rahul

Cooking or stove -originated fires are a significant group of residential fires. These fires start from a stove or a cooktop if it is left on alone, food is left on a hot pan for a long time or if there are other, flammable materials too close the high-temperature parts. Different technologies are already available to avoid such ignitions, including the stove guards that cut off the voltage when they detect a possible ignition. Although such technologies can be very efficient, I have started to think if the kitchen fires could be reduced with some other means. Could we prevent fires from igniting in the first place? Or could we improve safety without extra investment?

The importance of the stove fires is evident. According to the Finnish fire statistics of 2011-15 [1], the yearly count of building fires was 5760 in average, leading to 73 fire deaths and 124 M EUR direct economic losses annually. About 1000 (17 %) fires originated from cooking and 700 (12 %) from electrical appliances. In fire deaths, the shares of these two origins were  8.2 % and 7.4 %, respectively. On top of these, we have the ‘unknown’ category in each statistics.

So what technological change could make the change? Let’s have an analogy: When I started to work in fire research at the end of 1990’s, televisions were one of the most important ignition sources. A lot of effort was put in developing fire-safe televisions, mainly by using fire retardant polymers. Interestingly, about the time when the fire retardant polymers fully came into market, TV-technology changed from cathode ray tubes to flat screens, and televisions practically disappeared from fire ignition statistics. Natural evolution of the market removed the problem. Could we see similar evolution in stoves?

Based on my personal experience, induction heating -based stoves can make the difference. Instead of first heating the stove and relying on heat conduction to heat up the cooking pans or pots, an alternating magnetic field is used to create magnetic hysteresis and electrical current in the pan, which then heats up due to the resistance. The fire safety benefit is obvious because the amount of high temperature surfaces is reduced.

The yearly number of sold cooktops and kitchen stoves in Finland is about 168,000. In 2016, about 50,000 (30 %) of them were based on the induction technology [2]. The share of induction -based appliances is much higher in integrated cooktops (65 %) than in floor-standing stoves (10 %), but their shares are gradually increasing in both stove types.

To estimate the potential safety impact, we must compare the rate of stove renewals to the total population. At the end of 2015, there were 2,600,000 occupied dwellings in Finland, 45 % of them being in the blocks of flats [3]. Assuming that the floor-standing stoves are installed in flats, the share of induction stoves in these dwellings will increase only by 1 % each year. Also assuming that the integrated cooktops are installed in the other dwelling types, we can estimate that about 3 % of dwellings will have a new induction cooktop each year. If the share of the induction cooktops and stoves does not increase significantly, the possible safety benefit cannot be reached within the next 30 years. The impact will smallest in the low-investment housing, such as rental buildings. On the other hand, that’s where the cities and municipalities have the greatest power to influence.

I think this topic needs more research to investigate the potential safety improvement. First of all, we should understand the physics of stove ignitions and the difference between thermal conditions typical for different stove technologies. Second, we should estimate the potential for natural and enforced market shares, as well as policy making. When the money is tight, we should utilize the possibility.

References

1. Pelastustoimen taskutilasto 2011-2015. Pelastusopiston julkaisu, D-sarja: Muut 4/2016. 2. painos. http://info.smedu.fi/kirjasto/Sarja_D/D4_2016.pdf
   
2. Elektroniikan Tukkukauppiaat ry (ETK), www.etkry.com and www.gotech.fi. Visited December 2, 2016.
3. Official Statistics of Finland (OSF): Dwellings and housing conditions [e-publication].
   ISSN=1798-6761. Overview 2015, 1. Dwelling stock 2015 . Helsinki: Statistics Finland [referred: 10.4.2017].

Posted by Simo Hostikka

Aalto University is one of the organizers of the 2017 Nordic Fire and Safety Days.

There are still few days to submit your abstract. Last year, it was great event.

Posted by Simo Hostikka